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Identifier
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Thesis_MES_1997_FarrellT
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Title
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An investigation of food availability and nesting habits of the harlequin duck (Histrionicus histrionicus) on the Olympic Peninsula
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Date
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30 June 1997
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Creator
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Farrell, Tracy H.
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extracted text
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An Investigation Of Food Availability And Nesting Habits Of The
Harlequin Duck (Histrionicus histrionicus) On The Olympic
Peninsula
by
Tracy H. Farrell
A Thesis: Essay of Distinction
Submitted in partial fulfillment
of the requirements for the degree
Master of Environmental Studies
ABSTRACT
The objective of the paper is to better understand the habits of the Harlequin duck
(Histionicus histrionicus) to aid in Washington State' s efforts to protect this species. The
paper begins with an introduction to the life history of the Harlequin duck through a
literature review and a habitat characterization. Following this is data and analysis
regarding nest initiation timing relative to stream flow and a preliminary comparison of
Harlequin duck distribution on the streams of the Olympic Peninsula to benthic
invertebrate density.
The Harlequin duck is impacted by flood activity brought about by spring snow
melt on the interior mountain streams of its Western U.S. distribution. Data gathered by
brood surveys for the Washington State department of Fish and Wildlife was used to
determine the influence of spring stream flow regimes on the nest initiation of
Harlequins. From the data analyzed in this paper there was found to be no significant
difference in the mean nest initiation times of Harlequin ducks on the streams of the
Olympic Peninsula. Further there was no correlation between daily average stream flow
and the range of nest initiation times for the years 1991-94 and 1996.
It is also well documented that the Harlequin duck utilizes the abundance of
benthic freshwater larvae as a food source while on the breeding grounds. Using data
collected by the Washington Department of Ecology benthic invertebrate densities were
correlated to the occurrence of Harlequin ducks in pool and riffle habitats. On the
breeding grounds of the Olympic Peninsula there is a significant difference between
benthic invertebrate densities in the riffle habitat of streams that support Harlequin ducks
and the riffle habitat of streams that do not support Harlequin ducks. There is no
significant difference for the pool habitats compared for benthic invertebrate densities
with and without Harlequin ducks.
CHAPTER ONE: INTRODUCTION .......................................................................................................... 1
CHAPTER TWO: THE HARLEQUIN DUCK .......................................................................................... 6
INTRODUCTION ................................................ .............. .................. ...... ....... ...... ..... .. .... .... ... ....................... .... 6
DISTRIBUTION AND APPEARANCE .... .......... ....... ............................... ............... ...... .... ... ........ ....... .................. ... 7
TAXONOMY AND EVOLUTION .. .................. ..... .................. ...................... .... ... ............. ............ .. ... .. ... ...... ....... 10
POPULATION SIZE, DISTRIBUTION AND STATUS ..... .. .. ............. ............ .... ........ .............. ................. ............. .. 11
HABITAT UTILIZATION ... ... ..... ......... .... .... .. .... ........ ........ .. ...... .... ...... ................ .. .... ... ....... .... ....... .... ... .. .. ...... ... 14
Wintering Habitat ........ ................. .... ......... ............... .. ..... ........ ............ .. ..... ... ..... ....... ... .......... .............. .... . 15
Breeding Habitat ................. .... ...... .... ......... ................................................... ... .... ...... .. ..... ......... .... .......... . 17
CHAPTER THREE: HABITAT CHARACTERIZATION .................................................................... 25
INTRODUCTION ...... ......... ............. .......... ....................... ....... .... ..... ... .............. ................. .... .......... .. ..... ... ....... 25
RIPARIAN ECOLOGY............ ..... ...... .. ........ ....... .......... ........... ........ .... .............. ................ ... ............... .............. 25
BENTHIC INVERTEBRATES ......... ...... ... ..... .. ...... ..... ...... .... .... ... ... ..... ....... ... .............. ... .... ......... ........ .......... ...... 27
BIOASSESSMENT ........ .... ..................... ...... .. .... .. ... .. ............... .... ... ........... ... ...... ... .. .... ............ ........ ............ .. ... 28
HABITAT REQUIREMENTS ........ ...... ...... ............... ........ ... .... ......... ............................ ............. ................ ..... ..... 29
Specific Requirements ......... ... ... ..... ..... .................. ......... .. .................. ........... ......... ... ..... ..... ........ ... ....... .... 30
HARLEQUIN DUCK PRODUCTION .. .... ............... ............... ........... ....................................... .. ... ............ .. 30
Summary Statistics for Washington State ................ ... ... ........... .. ... ...... ..... ......... ........ .......... ............. ........ 31
Brood Requirements .. .................... ................ .. ... ... ..... ............. .............................. ......... ........ .. ... .............. 32
CHAPTER FOUR: NEST INITIATION AND THE ROLE OF STREAM FLOW .............................. 34
COMPARISON OF MEAN NEST INITIATION DATES ................................................ ............. .............. 34
Methods ... ..... .. ............. .... .... ..... .... ................. .... .......... ....... .... ........ ..... .............. .. ... .. .. ... ............ ............ .... 35
Results ............ .... .. ... .. ... ....... ..................... .... .... ...... ...... ..... .. .......................... ......... .... ........ ... ....... ............. 38
Discussion ................................... ...... ........ .. ....... ............ ... .. ....... .. ..... ....... ............ ... ... ................ ........ .... .. . 38
FLOW DATA CORRELATED TO THE TIMING OF NEST INITIATION .................... ......... ...... ........ ... 39
Methods .......... ......... .... ... ........ .... ...... ...... .... ............ .... .... ............. ............... ............ ........ ... ............ .. ... ...... . 39
Results ... .............................. ....... ...... ..... ..... ....... ............. .. ... ................................ .... .. ..... ... ............. ..... ..... . 41
Discussion .. ... .... ......... ................ ...... ................. ...... .............. .................. ............. ... .... .......... ............. ...... . 41
CHAPTER FIVE: INVERTEBRATE DENSITIES AND THE OCCURRENCE OF DUCKS ........... 43
Methods ................. .. ............. .... ............ .................. .......... ................ ... ........................ .... .......................... 43
Results ... ...... ........ ......... ..................... ...... ................ .. .............. ...... .. .... ...... .......... ........ ...... .... .... ... ... ...... .... 46
Discussion ........ .... ..... ................... ...... ........ .................. ...... ... .... ...... ............... ......... .... ....... ... ... ..... ..... .... ... 46
CHAPTER SIX: LAND MANAGEMENT, HUMAN ACTIVITIES AND
RECOMMENDATIONS ............................................................................................................................ 48
INTRODUCTION ...... .... ........ .. .. .......... ........... ......... .............. .... ......... .... .... ........ ...... .. ... .. .. ................ ...... ..... .... . 48
THE OLYMPIC PENINSULA ..... ........ .. .... .... ....... .. .... ... .......... ...... ........ ........ .......... ....... .. ....... ....... .... .. .... ... 48
Olympic National Park .. ...... ...... ....... .... ...... ...... ............ ....... ..... ... ............ ... ..... .. ... .... .... ........................... .. 48
Olympic National Forest ......... ..:.... ....... ............ .. .. ........ .. ...... ...... ........ ......... .. ..... ... ....... ...... ... ......... ..... ... .. 51
HUMAN ACTIVITIES ..... .... ... ..... .......... .......... ............... ........... .... ....... ................ ............... .... ...... ....... ....... 52
Historic Events .......... ..... ... .. .... ... ...... ........... .... ............. .... .... ........ ..... ...... ... ..... ...... ....... .... ... ........... .... ....... 52
Current Threats and Management ..... ...... .... ... .... ....... ...... ............. ... .. ............................... ... ....... .. ... ....... .. . 53
Recommendations ........... ...................... .... ............... ..... ...... .... ... .... ................... .......... ... ....... ........ ............ 57
LITERATURE CITED ................................ :.............................................................................................. 60
l1l
List of Figures
FIGURE 1. THE HARLEQUIN DUCK (HISTRIONICUS HISTRIONICUS) ............. .... .. ................ ... .... ......... 9
FIGURE 2. DISTRIBUTION OF HARLEQUIN DUCKS INN. AMERICA ...... .... ....... ... ... ..... ...................... 12
FIGURE 3. THE OLYMPIC PENINSULA ............................................................................................ .49
List of Tables
TABLE 1. STREAM SURVEY DATA ................................................................................................ 37
TABLE 2. NEST INITIATION DATA .......... ...... ...... ....................... ................. .. .... ........ ..... ... ........... .40
TABLE 3. lNVERTEBRATE DENSITY DATA ................................................................................... .44
TABLE 4 . INVERTEBRATE DENSITY DATA ...... .... ..... ....... ..... ... ...... .. .. ... ..... .... .. ........ ... ......... .. ...... . .45
iv
ACKNOWLEDGMENTS
In appreciation for the assistance and support I have received in
completing this paper I would like to thank Greg Schirato from the Washington
State Department of Fish and Wildlife for providing the data for this paper.
Furthermore I am grateful for his assistance and support in studying and learning
about the Harlequin duck. I would like to thank my faculty reader, Tom
Womeldorff, for agreeing to read and critique this paper for completion of the
requirements at The Evergreen State College. Tom has been a great teacher to me
for two years and an insightful reader. I am thankful to my mother, Judi Hawkins,
and my friend, Norm Hay for experienced text editing and baby-sitting. And
finally I am forever grateful for the love and support from my husband and
daughter Kevin and Caoilinn Farrell, without whom this achievement might not
have been realized.
V
CHAPTER ONE: INTRODUCTION
There are three objectives to this study: First, it is an exploration of the
ecology of the Harlequin duck (Histrionicus histrionicus) bearing in mind the
topography, water regime and riparian ecosystem of the Olympic Peninsula.
Second, it is an original coordination of brood survey data, stream flow data and
invertebrate density data with the objective of learning more about this species in
its breeding habitat on the Olympic Peninsula. Third, it is an in-depth and critical
look at the management practices and current issues surrounding the Harlequin in
Western Washington.
Understanding food resources, habitat characteristics, stream morphology
and the biology of the bird all have important bearing on the successful protection
of the Harlequin duck and biodiversity.
The integration of physiology and
behavior evolved by the Harlequin to survive is fascinating in its scope and
refinement. The management policy for the Harlequin is incomplete because the
understanding of its needs and pertinent threats are lacking.
The impetus of this paper is to make a critical assessment of the nature of
information and management practices regarding the Harlequin duck on the
Olympic Peninsula and to come up with some original conclusions about this
species. The unique position of the Harlequin as an indicator species and a link
between the coast and the mountain streams creates an opportunity to use this
duck as a guide in the management of wildlife that shares the breeding and
wintering habitats with them.
Effective Harlequin management relies on harvest prov1s10ns, habitat
protection and conservation. The gaps in our knowledge of this species creates
weaknesses and limitations in our ability to fully understand, and better manage
these birds. These deficiencies include poor harvest limits set by the evaluation of
dabbling duck populations, reliable information on diving duck harvest (Wick &
Jeffrey 1966), the incomplete evaluation of regional biology and habitat
requirements, and the analysis, synthesis and implementation of known data.
The Harlequin duck is not steeped in controversy and social issues to the
same extent as the Spotted owl (Strix occidentalis) or the Marbled murrelet
(Brachyramphus marmoratus). Nonetheless, as a species officially regarded by
the Washington State Department of Fish and Wildlife as a Priority Species, by
the U.S. Forest Service in the adjacent regions as a Species of Special Concern
and at one time a Category 2 candidate under the Endangered Species Act, the
Harlequin duck warrants special attention and as complete an understanding as is
possible.
The Washington State Growth Management Act (1990) regards the list of
State Priority Habitats and Species when planning and development are regulated.
This is particularly important because one premise of this paper is that the
consideration of Harlequin duck breeding and wintering habitat during relevant
times of the year for lowered impact, conservation and further study is necessary
2
in order to provide better management for this species.
The Harlequin duck is a species about which too little is known. It is a
fascinating bird that alternates wintering and breeding environments throughout
its range and utilizes the harshest zones of these habitats, namely turbulent and
fast moving water. This species spends the winters in the coastal environments of
the northern Pacific and Atlantic Oceans. In the spring, pairs migrate upstream to
breed in the active channel of the rivers where the females were hatched and
raised.
Harlequin ducks have evolved several behavioral characteristics to
overcome the rigors of inhabiting the fast waters of the active channel of a river
that is their breeding habitat. Research indicates that in their Rocky Mountain
breeding range nests initiated before the peak runoff from snow melt can be
devastated by the increased flow.
Harlequin ducks are regarded as late nesters and this behavior has been
linked to the increased stream flow events that regularly occur on the interior
glacially fed streams of their Rocky Mountain breeding habitats. High spring
stream flow is devastating to nests and broods because they can be washed away.
The males leave shortly after incubation begins for the coastal habitat and the
females are unable to replace this loss. A comparison of nest initiation and stream
flow data would be a good indication as to whether or not the spring precipitation
events impact the survival of this species along the breeding habitat of the
3
Olympic Peninsula.
The impact of food availability and abundance on the breeding habitat of
the Harlequin duck is unknown for the state of Washington. Currently there is no
quantitative data concerning exactly what these birds consume while living on the
rivers. It has been well documented that they are opportunistic feeders of
invertebrate species in both of their habitats. Some of the best data for this are
their selection of prey items on the rivers of their Icelandic distribution where the
most abundant insect larvae, Dipterans, constitute the majority of their diet
(Bengtson 1966; 1972; Gaines 1993; Gardarsson and Einarsson 1994). The
preliminary comparison of invertebrate densities on streams with and without
Harlequin ducks on the Olympic Peninsula can provide a base of knowledge that
will be useful in further studies.
The issues of concern for this paper are some aspects of their reproductive
biology, specifically the timing of nest initiation relative to the fluctuation of
stream flow, duration of nesting correlated to daily average streamflow and the
distributive influence of relative invertebrate densities on streams with and
without Harlequin ducks. This paper will introduce the reader to the Harlequin,
investigate briefly the habitat characteristics related to this species on the Olympic
Peninsula, and provide a comparison and analysis of brood survey, stream flow
and invertebrate density data from which further study and management
recommendations will be made based on the history and policy of the study area.
4
Chapter two based on a thorough literature review, is a summary of the
ecology of the Harlequin duck. The third chapter discusses the habitat
characteristics and present unde,rstanding of this bird along the riparian corridors
through short accounts of riparian ecology, habitat requirements and Harlequin
duck production.
Chapters four and five are a culmination of learning and understanding.
They introduce, analyze and discuss an original correlation of governmental data
records for stream flow (United States Geological Survey) and invertebrate
densities (Washington State Department of Ecology) with the activities of
Harlequin ducks on the breeding habitat of the Olympic Peninsula. Chapter six is
an introduction to the study area through geologic events and recent human
impacts covering the Olympic National Park and Forest, some historical events,
current threats
and
habitat
management.
Chapter
six
concludes
with
recommendations based on chapters two through five and a desire to perpetuate
this species far into the future.
5
CHAPTER TWO: THE HARLEQUIN DUCK
Introduction
The Harlequin duck (Histrionicus histrionicus) is designated as a priority
habitat species by the State of Washington. This means that this species and its
habitat are indicated as a preferentially ranked and, therefore qualifies for
management and preservation by state wildlife officials (Schirato 1994).
However, because of a lack of information about certain critical aspects of this
species' habits in Washington, there is a\need for further studies. The intention of
this paper is to summarize the phenology (life history), reproductive and survival
rates of the Harlequin duck, and based on information cited in the literature,
examine the impact of streamflow and invertebrate density cycles on distribution.
This information will be addressed in concert with the influence of human activity
on the Harlequin duck's breeding grounds and the resulting implications for
management practices and conservation.
The phenology, reproductive and survival rates of the Harlequin will be
discussed according to the most current literature available for the Pacific
Northwest population. This species occupies a unique position as an indicator
species and a link between the coast and the mountain streams (Chadwick 1993).
This creates an advantage for this duck in the management of wildlife because of
a traditionally specialized focus on species that use a range of sensitive habitats.
The ecological dependency of the Harlequin on the components of its anadromous
life cycle obliges us to fully understanding and evaluate the coastal and riparian
6
habitat components essential for its persistence over time (Ruggiero, Holthausen,
Marcot, Aubry, Thomas and Meslow 1988).
Distribution and Appearance
In the state of Washington the maritime distribution of Harlequins
includes northern Puget Sound, northern Hood Canal, the Straight of Juan de
Fuca, the San Juan Islands, and the outer coast. Interior distribution in the state
includes the Olympic, Cascade, Blue and Selkirk Mountains (Gaines 1993). The
interior U.S. distribution of the breeding Western population outside of
Washington include Oregon (39 streams), Idaho (35 streams), Montana (40
streams) and Wyoming (19 streams) (Status Report 1993).
The appearance of the Harlequin duck is as unusual and enigmatic as its
anadromous life cycle. Linnaeus is responsible for the use of Harlequin as the
common name that is used throughout this text and in nearly all other literature on
this subject. This colorful descriptor indicates how influential the nuptial plumage
of the male is to the image we have of this energetic little bird (Friederici 1996).
The female and the juvenile birds have much duller plumage and are very similar
to each other. The juvenile males do not have full nuptial plumage until their
second summer (Status 1993).
All plumage colorations and patterns are cryptic enough to obscure the
shape of the bird and to blend its movements into the waves and riffles of the
habitat where it can be found (Figure 1). The males have a blue-grey foundation
7
with a burnt sienna patch posterially beneath each wing and a same color strip
near the crown. The most striking feature of their plumage is the intermittent
distribution of white dots, dashes and commas, most of which is bordered by
black that melts unnoticeably into the blue-grey background. The females and
juveniles are a dull brown with three indistinct white spots on the head.
8
,
'!,•• ··· -
' ...;.~,:::i:~
0
Figure l. The Harlequin Duck (Histrionicus histrionicus).
Taxonomy And Evolution
The taxonomic placement of the Harlequin duck is in the tribe Mergini in
the family Anatidae. As a member of the Mergini or sea duck tribe, several
evolutionary features in common with the other members of this group
characterize the Harlequin duck. However, it is more closely related to the Scoters
(Melanitta) and Oldsquaw (Clangula) than the Eiders and other diving ducks
(Johnsgard 1960). This duck differs most distinctly from these other genera in its
breeding migration from the ocean coasts to fast water habitats in mountain
streams. This migration pattern makes the Harlequin duck ecologically unique.
There is no other similar waterfowl in the Northern Hemisphere. In the Southern
Hemisphere only the Blue duck (Hymenolaimus malacorhynchos) and the Torrent
duck (Mergaetta armata) are adapted to swift flowing mountain streams (Kuchel
1977). However, they do not lead an anadromous life as the Harlequins do
(Cassirer 1991 ).
The Harlequin's fossil history is recorded as early as the Pleistocene Era
(California, Alaska, and Sweden) (USFWS 1994).
They are considered a
monotypic species among a diverse collection of diving waterfowl, with an
equivocal evolutionary history based mostly on reproductive behavior and
esophageal physiognomy (Johnsgard 1960). They are thought to have evolved in
the western part of their population distribution and later migrated eastward. This
theory is based on the number of ducks that occur regionally (Turbak 1997).
10
Population Size, Distribution And Status
The Harlequin duck population has a disjunct, Nearctic frequency (Figure
2) with the greatest population concentrated in the northern Pacific and smaller
populations located in Iceland, Greenland and northeastern North America
(Vermeer 1983). These populations range in size from less than five hundred
breeding pairs on the Atlantic coast of North America to close to one million
individuals observed wintering in the Pacific off the Coast of Alaska. Iceland and
Greenland each have approximately ten thousand birds determining the breeding
populations (Breault & Savart 1991 ). The distribution of the Harlequin duck
expands in the spring and summer when pairs travel inland to breed on coastal and
interior streams. Washington State is home to the largest population of Harlequin
ducks in the lower 48 states.
II
-
, w¾
,,
..
~
..:.·.. . ..
~
.,
a,,
....
....
·.·:
,
:•·
Breedlngrang•
rBJ
Wlnlwrang•
~
Hlalol1C l>rHCll"II range
~-···-
m
'?
C
Figure 2. Distribution of Harlequin ducks in North America. 1993. Breeding status is unknown on Baffin
Island New Brunswick and Quebec north of the Gulf of St La\\Tence in the Atlantic population. Status is
unknmm in the Blue Mountains of Oregon and Washington. the southern Cascades of Oregon and many
areas of western Canada and Alaska in the Pacific population (Status 1993).
The population size and its change over time are indicators of whether a
species can remain successful under the pressures of human impact. The only
designated endangered population of Harlequin ducks is the Atlantic population
that breeds in the coastal region of Canada. The endangered status was given by
the Canadian government in 1990 (Status 1993). The U.S. policy for the East
coast population, covered under the federal hunting regulations outlined by the
Migratory Bird Treaty Act (1918), is the elimination of hunting in the State of
Maine (Chadwick 1993; Turbak 1997).
The estimated minimum viable population size for the eastern population
of the Harlequin is between 715 to 1785 breeding adults. These calculations are
from the research of I. Goudie (1992) based on the theory put forth by Soule
(1987). Soule describes population viability and conservation through the
relationship between population lifetimes and the various conditions that can
influence those lifetimes, including stochastic events, abundance, distribution,
habitat availability and abundance of the species. The Harlequin appears to be
retracting from its usual historical distribution along the breeding grounds (Genter
1993).
Although it has suffered less from the impact of human disturbance
because of the selection of remote areas to winter and breed, there is cause for
concern as the expansion of land use increases.
The United States Forest Service classifies the Harlequin as a Sensitive
Species, incorporating specific management policy in areas where they occur for
13
Region 1 (Montana, northern Idaho, North Dakota, and northwestern South
Dakota) and Region 4 (southern Idaho, Nevada, Utah, and western Wyoming).
The United States Department of the Interior-Bureau of Land Management has
also developed streamside management zones that include concern for the
Harlequin duck (USFWS 1994).
However under the 1976 National Forest
Management Act, the Forest Service classification has more legal bearing than the
management policies of the BLM (Clark, Reading and Clarke eds. 1994).
Washington is the only state that has developed a management policy for the
habitat of Harlequin ducks where it is managed as a Priority Species. In Oregon
they are designated a state sensitive species; in Idaho and Montana they are a
species of special concern (Status 1993).
Habitat Utilization
The Harlequin selects wintering and breeding habitats by a combination
of availability of specific habitat requirements and site fidelity (Bengtson 1972;
1966; Gaines 1993; Gardarsson & Einarsson 1994). These birds migrate mostly
in pairs to their natal breeding grounds during the late spring and early summer
months. Males return to their wintering grounds starting in June while females
and juveniles migrate in September. They winter on the coasts of the region
where they live and breed mostly on first-,
second-, and third-order streams
(Bengtson 1972; Genter 1993). This movement back to the coast is done in order
to molt in a safe and productive habitat. The following sections will describe the
coastal and riparian habitats used by Harlequin ducks and their migration timing.
14
Wintering Habitat
The Harlequin duck is a sea duck and spends the majority of its life
foraging on the rugged coasts of its range. Males spend as much as ten months of
the year on their wintering grounds (Fleishner 1983). Although a sea duck, the
Harlequin has adapted a cycle in its life for breeding on mountain streams.
However, the capacity of the streams to support the ducks is ephemeral, requiring
the ducks to return to the sea.
There are many factors that contribute to the
distribution and composition of Harlequin duck populations along its wintering
habitat. These include food availability, site fidelity and safety from predation
(Salomonsen 1968).
Food and Feeding
Harlequins are social when wintering and congregate in flocks discreetly
distributed over their selected range. They are adept divers and prefer to stay near
shore over gradually sloping cobble or cobble/rock substrate in order to feed
(Bengtson 1966). Hirsch's (1980) research shows a preference by Harlequins on
the inland waters of Washington for gradually sloping, sandy substrate featuring
an eelgrass ecosystem. Further habitat parameters include a preference for low
depths and short distances from the shore.
Harlequins exhibit distinct habitat preferences along the coast of
Washington, and although no quantitative data on diet has been collected, possible
sources of food are crustaceans including small crabs (Hemigrapsus spp.), isopods
15
had no conspicuous benefits over nearby sites of comparable value leading to the
conclusion, based on the literature, that food availability is the cause for this
arrangement of dispersal. The flocks of ducks vary considerably in size; they are
in the hundreds along the coast of Washington and reach the thousands along the
Aleutian Islands of Alaska (Breault & Savard 1991; USFWS 1994; Friederici
1996).
/7
The Harlequin duck has a complex phenology. This bird is slow to reach
sexual maturity, the clutches are small, there is low recruitment annually, and they
are long-lived, which makes them a K-selected species with populations
comprised primarily of adults and sensitive to any increase in mortalities (Goudie
1996). As a result of this reproductive strategy that leads to a population
composed mostly of adults, there are questions about the wintering ecology and
survival of the juveniles (Chadwick 1992, Proceedings; Fleishner 1983).
Observations indicate that discreet congregations of age classes characterize the
winter gathering activities of Harlequins.
Greater quantitative data on winter
ecology and survival of juveniles would contribute considerably to current
knowledge.
Breeding Habitat
Like the salmon, the Harlequin ascends rivers and return to its natal stream
to reproduce. In Washington and the other northwest states of its territory the
Harlequin breeds mostly on first-, second-, and third-order streams (Bengtson
17
1972; Genter 1993 ). Their migration begins near the end of March and beginning
of April in Washington, and is influenced by environmental factors (Kuchel
1977).
The most important characteristics of the stream habitat are food
availability, nesting and loafing sites, slow water areas for young broods, and
isolation (Kuchel 1977).
Many physical and morphological features of the
nparian area can be identified for promoting these important characteristics
including stream gradient, width, depth, substrate, velocity, turbidity, bank
vegetation, woody debris, and sinuosity (Bengtson 1972; Beschta and Platts 1986;
Stanford and Ward 1992; Status 1993).
The Harlequin may leave the coast, but the turbulent waters that it does so
well in are also selected for in its stream habitat (Bengtson 1966; 1972; Inglis,
Lazarus and Torrence 1989; Genter 1993).
The composition of the stream
includes riffles, pocket water and runs, cobble and boulder substrate, trees and
shrubs (Gaines 1993).
The streams are usually straight and confined by the
geomorphic surface of the river valley (Gaines 1993; Gregory 1991 ). All of these
factors vary regionally in providing acceptable breeding habitat (Bengtson 1966;
1972; Cassirer & Groves 1991; Gaines 1993; Jarvis & Bruner 1996; Kuchel
1977).
Food and Feeding
Harlequin ducks feed almost exclusively on animal matter, but do not
specialize in their selection of prey species (Bengtson 1966; 1972; Bengtson &
18
Ulfstrand 1971; Inglis et al. 1987; Kuchel 1977).
Their food base switches
according to whether they are in a marine or freshwater environment. Keeping in
mind the evolutionary theory for r and K-selected species, this limited food base
gives some evidence for the following adaptations: harlequins breed relatively
late, the females' lay smaller clutches of larger eggs, the young fledge quickly and
the males depart soon after the incubation phase begins (Bengtson 1966). In the
freshwater environment, the Harlequin duck feeds almost exclusively on insects.
The emergence of insect larvae impacts the timing of migration, the distribution
and productivity of these birds along the stream during their breeding and nesting
cycle (Bengtson 1972; Bengtson & Ulfstrand 1971).
Several sources describe the Harlequin as an opportunistic feeder of high
protein foods, almost exclusively benthic invertebrate larvae (Bengtson 1966;
1972; Bengtson & Ulfstrand 1971 ; Gardarsson & Einarsson 1994; Inglis et al.
1987).
Studies in Iceland show that the blackfly (Dipteran) larvae are their
primary source, with up to 99% of stomach contents containing this species
(Bengtson 1972).
Other studies indicate predation of Plecopterans (stonefly
larvae) and Ephemeropterans (mayfly larvae) where these species are
dominant/abundant (Wallen 1987).
Wallen (1987) observed the casings of
caddisfly (Tricopteran) larvae in fecal material in his study of Harlequin duck
ecology in Grand Teton National Park. It has yet to be determined what the
Harlequin eats on the streams of Washington.
19
Courtship
Outside of feeding, the most important activity for survival of a species is
reproduction. Reproduction for this species involves ritualized courtship displays,
pairing, migration to the breeding grounds, copulation, nesting and brood rearing.
Their breeding behavior has few visual components because of the difficulty of
displaying on turbulent waters. The reduced use of vocal communication has
evolved because of the constant background noise that dominates their white
water habitat (Inglis et al. 1989). Courtship displays begin on the coast preceding
the breeding migration to natal streams and the Harlequin continues to perform
courtship displays and copulate on the breeding grounds (Genter 1993).
Migration
Site fidelity or philopatry is well developed in the Harlequin and has been
recorded in both sexes. The Harlequins form a pair bond and are known to return
to nearly exact locations (ex.: same loafing sites) each year (Bengtson 1972;
Crowley 1993 ; Gaines 1993; Goudie 1996; Kuchel 1977). The vast majority of
sexually mature Harlequins are paired before entering the riparian system (Genter
1993). Unpaired sexually mature males also migrate to the breeding grounds.
Aldrich (1983) describes this as a mechanism for stimulating courtship behavior
and providing further opportunity to breed if a paired male is killed on the stream
or during migration.
Unpaired females have also been documented on the
breeding grounds. Researchers have concluded that these birds are underaged non-
20
breeders prospecting for next season or birds that have lost their brood (Wallen
1987; Cassirer & Groves 1991)
There are no conclusive reports on how Harlequins migrate to and from
the breeding grounds. It is certain that whenever possible they fly low over the
active river channel paralleling each bend.
Yet, birds have been documented
outside the riparian corridor of final breeding destinations (Cassirer & Groves
1991 ). Furthermore, the populations that breed east of mountain divides must fly
overland to arrive there.
Behavior
Kuchel ( 1977) divides the breeding season into two periods, courtship and
nesting, and brood rearing. The times of these events differ regionally but the
duration is relatively stable. Courtship begins on the coastal waters where the
Harlequins begin pair formation. Furthermore, characteristic duck breeding
behaviors, such as head nodding and rushing, are sparse (Kuchel 1977; Inglis et
al. 1989). The males are not territorial but defend an area around the female
(Inglis et al. 1989; Bengtson 1972). The females' prone position when soliciting
her mate is a distinguishing behavior of the Mergini tribe (Inglis et al. 1989).
However, the male Harlequin's act of pecking the back of the female's neck
differentiates the Harlequin within this tribe and Inglis et al. (1989) give this as
evidence of a primitive evolutionary link to the Cairini tribe because of its
resemblance to the Wood Duck's (Aix sponsa) behavior.
21
Nesting
Until nesting begins, the females stay within a few meters of the stream
(Inglis et al. 1989). Once nest prospecting begins, the females will spend hours
walking on shore or will fly to search for cavities (Bengtson 1966). The
requirements for nesting vary regionally and nests are found in a variety of sites:
ground, ledges, snags, cavities and log jam debris (Breault & Savard 1991 ; Genter
1993 ; Status 1993).
Breault and Savard (1991) suggest that nesting in short coastal creeks
contribute greatly to annual Harlequin duck production. This is because of the
availability of marine invertebrates, which are far more numerous than freshwater
invertebrates and closer to nesting and brood rearing areas than if the families
were significantly farther up stream. In contrast, Crowley (1993) who studied the
Harlequins breeding in eastern Prince William Sound, stated that the productivity
of coastal breeding Harlequins is similar to that of inland breeders.
An interesting aspect of the Harlequins' nesting behavior is that of timing.
The late nesting time of the Harlequin duck corresponds to the condition of the
breeding habitat, the food supply and the lack of possibilities for renesting
(Bengtson 1966). The timing of nesting (Glacier National Park, Montana) is
correlated to spring stream runoff and food availability (Kuchel 1977; Bengtson
and Ulfstrand 1971 ). Stream runoff has a devastating effect on Harlequin nest
sites if the sites are selected too early (Kuchel 1977; Wallen 1987).
In
22
variation in productivity among the western coterminous United States is said to
be primarily the difference among the success of the broods (Genter 1993).
Mortality is highest within the first two weeks after hatching (Bengtson
1972; Kuchel 1977). The ducklings' survival is based on the availability of food
and their ability to escape predation (Kuchel 1977).
The architecture and
complexity of the stream provides the necessary food supplies and refugia for
adequate survival to fledging (Cassirer 1991; Genter 1993; Wallen 1987).
The reproductive cycle is complete when the females and their young
travel back to the coast. The timid nature of this bird makes it difficult to observe
the downstream migration of the females and juveniles. This migration of females
and juveniles begins as a downward stream expansion of home range (Kuchel
1977). There is some conflict in the literature about whether or not the hen escorts
her brood. The majority of the literature supports the theory that the females lead
their young to sea (Kuchel 1977; Breault & Savard 1991; Inglis et al. 1989).
However, there remains strong evidence for the abandonment of broods by
females in order to molt (Cassirer & Groves 1991 ). The reason for this variance
perhaps lies in the distance needed to travel. Females closer to the marine
environment may stay longer on the stream with their broods.
24
CHAPTER THREE: HABITAT CHARACTERIZATION
Introduction
The Harlequin duck spends the breeding season on the rivers and streams
of the Olympic Peninsula. The basis of this paper is to focus on some aspects of
this species activity and occurrence during the breeding season on the rivers and
streams. The two issues that are raised involve the timing of nest initiation and its
relationship to seasonal stream flow activity and the appearance of this species on
streams that have varying benthic invertebrate densities. This chapter goes into
detail about riparian ecology, habitat requirements and duck production in order to
build a foundation for the conservation, management and study recommendations
that conclude this paper.
Awareness of the npar1an system and the following specific habitat
characteristics and requirements will allow for a better judgment of the
importance of stream flow events to the Harlequin duck on the Olympic
Peninsula. This chapter addresses the dimensions of the lotic habitat. In the
section titled Riparian Ecology, benthic invertebrates and bioassessment are
discussed. Next the section titled Habitat Requirements, explains a theory of
habitat selection and lists observed specific habitat features. The section titled
Harlequin Duck Production details the breeding population of the Olympic
Peninsula and discusses habitat features necessary for brood rearing.
25
Riparian Ecology
Stanford and Ward (1992) characterize nvers as multi-dimensional
environments that connect hydrological and biological processes. The dimensions
are upstream-downstream, channel-hyporheic (groundwater), and channelfloodplain (riparian) zones, which are differentially acted upon over time. The
river is an energy transfer system, the structure and process of which is
determined by its interface with adjoining ecosystems (Gregory 1991 ).
The availability of energy sources to the Harlequin from the abundance of
the lotic ecosystem is crucial to its productivity.
The system should be as
undisturbed and unaltered from the headwaters to the estuary as possible in order
to provide a complete delivery of organic material.
This organic material is
consumed, abraded, fragmented, leached and released by a variety of mechanisms,
not the least of which is the diversity of macroinvertebrates that provide the food
supply for the Harlequin (Gregory 1991 ).
Channel morphology and overland flow are essential to the function of a
lotic ecosystem. If this morphology is altered or manipulated in any way, it can
be devastating to the survival of the Harlequin. The river channel is of utmost
importance to them as its geomorphic surfaces create physical patterns that help
define the diversity of adjacent plant communities and occurrence of aquatic
invertebrates (Gregory 1991).
Overland flow 1s determined by the amount of water not absorbed,
26
evaporated or transpired from net precipitation m the form of snowmelt and
rainfall. If the amount of absorption by soil surface and evapotranspiration by
plant communities is altered, it will seriously impact this part of the system to
increase overland flow (Hewlett and Nutter 1969). Human activity or natural
disaster can cause a significant change in normal overland flow and the result
could impair the Harlequins' ability to feed, raise their broods and consequently
survive. The increase in overland stream flow for the purposes of this paper is
linked to the survival of nests and young ducks. A comparison is made between
spring stream runoff and the timing of nest initiation within and between years.
The purpose of briefly discussing overland flow is an effort to highlight the
potential influence of outside forces upon a critical component of Harlequin duck
habitat.
Benthic Invertebrates
The amount of literature available on the subject of Harlequin diet on the
breeding streams is meager. Furthermore, the information available is moderately
inconclusive because of its statistical limitations. Nonetheless, it can be stated
that these birds are opportunistic feeders of high protein food types and that likely
sources are the dominant or most abundant aquatic insect larvae. The species of
aquatic insects observed in the studies done in comparative proximity to the
Western Washington population could have bearing on future studies and the
implementation of management practices.
27
Wallen (1987) sampled known Harlequin streams and insect remains from
Harlequin gizzard contents and fecal components in Death Canyon, Grand Teton
National Park.
He identified five genera of Plecopterans, nine genera of
Ephemeropterans, seven genera of Trichopterans, five families of Diptera and two
families of Coleoptera from the kick net survey at feeding sites in Death Canyon.
Ephemeropteran remains were identified in the gizzard (Heptagenia sp.). Fecal
components included the casings of Trichoptera (Glossoma sp.) and the
exoskeletal and gill remains of Plecoptera (Megarcys sp. and/or lsoperla sp.),
Ephemeroptera (Drenella spp.) and Trichoptera (Parapsyche sp.). Another study
done in Wyoming found the stomach contents of two birds contained up to 90%
Plecopterans (Cottam 1939). In Oregon, an observation of high abundance of
Trichopterans along the streams where Harlequins were captured and studied has
been indicated as a food resource (Jarvis 1996).
Bioassessment
Biological assessment (bioassessment) is the technique used to quantify
characteristics of the ecosystem and to determine environmental quality through
the use of reference locations and overall analysis and comparison. Bioassessment
as mandated by the 1972 Federal Clean Water Act (sec. 101) focuses on the
quantity and diversity of macroinvertebrates. Considering the influence of food
availability and distribution on the life cycle and physiology of the Harlequin
duck, the data collected for the bioassessment research from the Washington State
Department of Ecology has some potential for understanding this species.
28
For this study invertebrate density data in pool and riffle habitats for the
years of 1994 and 1995 are used. This data can be useful in the evaluation of one
or more levels of an ecosystem. For the Harlequin, these data are not precise
enough to show local species abundances available as a food resource. However,
these data are used to establish a correlation between the appearance of
Harlequins on streams and invertebrate densities thus providing a statistically
viable conclusion about the ecology of the Harlequin duck on the Olympic
Peninsula.
Habitat Requirements
The close association of Harlequins with specific habitat components
should determine management priorities in the effort to allow for the persistence
of this species (Cassirer & Groves 1991 ). The selection of habitat is hierarchical.
That is, in general the preference of habitat type precedes the selection of
homerange. However, further assumptions must not be overlooked, such as the
constraint of habitat selection, the role of critical environments and the
interpretation of preference. Dependency perhaps is not a useful measurement of
the state of nature, but a useful concept or framework upon which to arrange our
understanding of discreet populations and habitats (Ruggiero et al. 1988).
Furthermore, the availability of optimal conditions throughout the range may not
be possible to achieve, but through careful management there is the potential to
secure acceptable habitat (Hochbaum 1946).
29
The population of Harlequin ducks breeding on the Olympic Peninsula is
considered an ecotypic variation.
As an ecotype, they are adapted to local
conditions of the coastal mountain range and differ from other distinct breeding
populations in their reproductive timing and selection of other habitat components
such as food types (Ruggiero et al. 1988).
Specific Requirements
The habitat characteristics that define the availibility of food include
swiftly flowing water, substrate type, stream gradient, reticulate canyons and
vegetation. Habitat features that improve brood habitat and increase the value of
specific sites are slow water areas, overhanging vegetation, undercut banks and
woody debris. Threats include predation, catastrophic flooding events, hunting,
and human recreational and commercial activities (Cassirer 1991; Clarkson 1992;
Genter 1993; Goudie 1996; Wallen 1987; Status 1993).
HARLEQUIN DUCK PRODUCTION
Studies of Harlequins on the Olympic Peninsula have documented them
on 19 river systems. The densities that were observed did not exceed two pairs
per kilometer, with a minimum estimate of approximately 300 birds.
The
Harlequin selects for a distinct range of stream gradient ( 1-7%), and are not found
on the lower portions of the Western streams. In predicting the breeding habitat
of Harlequins, the most reliable feature appears to be stream morphology
(Schirato & Sharpe 1992).
30
The stream orders that Harlequin ducks have most frequently been found
on in the contiguous United States are those most likely to be impacted by human
land-use and recreational activities (Beschta & Platts 1986). Much of the human
land-use activities involve clearing vegetation along the streams. This vegetation
causes diurnal fluctuation of stream flow through evapotranspiration (Hewlett &
Nutter 1969). Harlequins favor certain depths of rapids and waterfalls and feed in
a two-peak pattern corresponding to these depth preferences. The alteration of
stream vegetation could have an impact on their feeding success and food
availability (Bengtson 1966; 1972).
Turbulent, whitewater streams are a high priority for Harlequin ducks
because of the increased availability of insect larvae that favor these habitats over
muddier calmer waters (Genter 1993; Inglis, et al. 1989). The complexity of the
stream habitat composed of riffles, runs and pools, contributes to the health of
these communities by dispersing energy and oxygenating the water (Beschta &
Platts 1986).
The lives of Harlequins on the streams are measured as productivity, or the
ability to survive and reproduce. The survival of adult females is important to the
stability of the Harlequin population, since it is their contribution as producers
that is crucial to population endurance. Population statistics in Washington are
calculated from the winter flight surveys, from band returns and resightings and
by occasional stream surveys.
31
Summary Statistics for Washington State
It is estimated that there are at least 152 pairs of Harlequins nesting on the
Olympic Peninsula with densities along the streams of 0.01-1.6 pairs / km. The
stability of this population is not known. Productivity measurements available are
brood sizes averaging 4.4 (N = 35) in 1991 and 3.3 (N = 24) in 1992.
Radiotracking efforts to assess mortality showed none after 30-45 days (Schirato
1994).
However, enough work has not been done in this area to develop
meaningful results for the state of Washington. Nest sites were located most often
on mid-islands of channels where predation of eggs by river otters and black bears
were observed. Three of twelve birds banded and radio tagged on the stream in
1992 returned the next year. The harvest records are negligible (Schirato 1994).
Brood Requirements
Pair density can be correlated to some available habitat components.
Cassirer (1991) study of the Harlequin breeding population in Idaho drew the
following conclusions about the selection of habitat based on brood requirements.
Overall requirements for production by Harlequins are vague, and because of the
nature of philopatry, annual population densities reflect the production of previous
years.
Components of good brood habitat are smaller streams, slower water,
more woody debris, vegetative overhang and bank undercut. This list is based on
the comparison of streams with higher pair densities to those with lower pair
32
densities. Mature forest overstory was correlated to the selection of brood habitat
but this is thought to be because of the low human impact and pristine nature of
the habitat and not because of the availability of vegetative features (Cassirer &
Groves 1991 ). Harlequins are highly adaptable throughout their breeding range
and very few characteristics remain constant as predictors of Harlequin duck
occurrences. Those that do are repeatedly cited as the variables influencing the
distribution and density of benthic invertebrates.
This collection of Harlequin duck knowledge is valuable, but of limited
use because there are too many variables not available for the characterization of
the Washington population. What can be said about and what is observed from a
few discreet populations cannot be fully extrapolated for use in management of
separate populations responding to disparate food sources, habitat components
and environmental factors.
Currently general ecological features are projected upon distinct ecotypes
to devise and implement management decisions. The information presented in this
paper is the comparison of local hydrological events to nesting activity and
invertebrate densities to occurrence. The intent of the author is to contribute to
more effective management of the Harlequin duck on the Olympic Peninsula.
33
CHAPTER FOUR: NEST INITIATION AND THE ROLE OF STREAM
FLOW
COMPARISON OF MEAN NEST INITIATION DATES
Because the Harlequin ducks of the Rocky Mountain breeding area are
vulnerable to the peak stream flows of the spring thaw it is the author' s intention
to determine if there is any similar phenomenon acting upon the breeding
population of the Olympic Peninsula. The literature supports the devastating
impact that a major flooding can have on nests and young broods in Montana
(Bengtson and Ulfstrand 1971 ; Diamond & Finnegan 1993; Kuchel 1977). It is
relevant to know what impact if any there is from increased spring flows from the
higher rate of rainfall precipitation observed each year and spring run-off on the
Olympic Peninsula.
Two tests are used in this chapter to evaluate if stream flow affects the
timing of nesting of Harlequin ducks on the Olympic Peninsula. These statistical
comparisons are set up to determine if there is any similarity between the results
of increased spring run-off from the Olympic Mountains and the glacially fed
streams of the Rocky Mountain habitat.
The first part of this chapter is an examination of stream flow during
average years and the year of a flood event. The comparison is made using the
grouped mean nest initiation dates of four years compared to the mean nest
initiation dates of one year with a notable flood event. The purpose is to acquire
preliminary information about the effect of high stream flow on nesting Harlequin
34
ducks.
The second part of this chapter correlates average daily flow data and nest
initiation dates. This comparison evaluates average daily stream flow relative to
observed dates of nest initiation. The purpose of this correlation is to gain
introductory knowledge on the relationship of daily stream flow influx to a range
of nest initiation dates in order to evaluate the influence of stream flow on nesting.
Methods
Data of brood size and age (Table 1) was collected from stream surveys
(N . Perfido) done in the months May, June and July of the years l 99L 1992, 1993.
1994 and 1996 by observing females with broods. Nest initiation and hatching
times were calculated by backdating from the estimated class age of each cohort.
Backdating times are based on the chronology of plumage development in
juvenile Harlequin ducks from Wallen (1987) that was developed from the work
of Gollop and Marshall (1954) for the Mississippi Flyway Council. The rivers
surveyed were the Hamma Hamma, Duckabush, Quilcene, Dosewallips, Elwha
Dungeness Rivers and Morse Creek.
In order to compare mean nest initiation dates for these times the dates
were converted to Julian dates. The data was grouped into all years before 1996
and tested against the data from 1996 when an unusually high spring flood event
occured. The null hypothesis is that of no difference between the means of nest
initiation timing between the grouped years before 1996 and the year of 1996. The
statistical analysis used was a Student' s t-test with a = .05 , a two-tailed
35
distribution and equal variance about the mean.
36
Date Obs.
Class
Julian date
Est. Hatch
Est. Nest
River
No. of young
6/ 1 l /91
lb
121
6/3/91
5/1/91
Dose
2
6/11/91
lb
121
6/3/91
5/1/91
Dose
6
8/ 17/91
Ile
163
7/1 6/91
6/12/91
Quilcene
4
5/29/92
lb
108
5/2 1/92
4/ 17/92
Ducka
5
6/3/92
Ia
119
5/3 1/92
4/28/92
Dose
1
5/2 1/92
midpoint
129
6/4/92
5/8/92
Elwha
eggs-no.unk
7/23/92
III
132
6/1 4/92
5/11/92
Quilcene
3
6/5/92
(first 1/3)
142
6/24/92
5/21 /92
Dungen
eggs-no. unk
6/ 10/93
<6days
122
6/5/93
5/2/93
Morse Cr.
4
6/ 10/93
<3days
125
6/8/93
5/5/93
Morse Cr.
2
6/25/94
Ile
111
5/24/94
4/21 /94
H.Hamma
4
6/7/94
le
112
5/26/94
4/22/94
Ducka
5
6/ 16/94
Ila
116
5/29/94
4/26/94
Quilcene
I
6/17/94
Ila
117
5/30/94
4/27/94
H.Hamma
5
6/ 17/94
Ila
117
5/30/94
4/27/94
H.Hamma
4
6/25/94
Ila
125
6/7/94
5/5/94
H.Hamma
2
6/ 14/94
Ia
129
6/1 1/94
5/9/94
Ducka
7
6/7/94
midpoint
139
6/21 /94
5/19/94
Ducka
8 eggs
6/23/96
III
103
5/ 15/96
4/12/96
Morse Cr.
4
7/ 18/96
Ill
128
6/9/96
5/7/96
Morse Cr.
4
7/1 0/96
Ilb
134
6115/96
5/ 13/96
Ducka
2
7/ 11/96
Ila
143
6/23/96
5/22/96
H.Hamma
2
7/24/96
Ilb-Ilc
146
6/27/96
5/25/96
Ducka
4
7/24/96
Ilb
148
6/29/96
5/27/96
H.Hamma
1
7/ 11 /96
lb-le
151
7/ 1/96
5/30/96
H.Hamma
3
7/20/96
Ila
151
7/2/96
5/30/96
H.Hamma
2
7/20/96
Ila
151
7/2/96
5/30/96
H.Hamma
3
7/28/96
Ila-Ilb
156
7/6/96
6/4/96
Ducka
4
7/24/96
lb
165
7/16/96
6/ 13/96
Ducka
I
Table I. Stream survey data for 1991-1994 and 1996 (N . Perfido 1997)
37
Results
The comparison between nest initiation dates resulted in no difference (p <
.01 ). There is no discernible effect from the higher spring stream flow of 1996
compared to the previous years on the timing of nest initiation of Harlequin
ducks on the Olympic Peninsula.
Discussion
The Harlequin duck has a high juvenile survival on the streams where they
have been observed (Goudie 1996). For the years compared in this paper,
streamflow did not influence nest initiation timing. This indicates that the river
systems of the Olympic Peninsula characterized by precipitation do not threaten
nesting Harlequins with devastating flood events compared to the river systems of
the Rocky Mountains dominated by snow melt runoff.
This comparison of mean nest initiation times is at best weak. There are no
more than five data points for one river in one year (Hamma Harnrna 1996). For
the purposes of this paper the rivern were grouped. The year of 1993 was left out
because there were only two observations of very young broods that had nest
initiation dates only three days apart, providing a very narrow range and a weak
set of data.
38
FLOW DATA CORRELATED TO THE TIMING OF NEST INITIATION
Average daily flow data was acquired from the USGS for the purposes of
comparing flow trends to the nesting activities of the Harlequin duck on the
Olympic Peninsula (Table 2). This is another way to observe the influence of
stream flow on the nest initiation of the Harlequin duck. This answers basically
the same question as before but defines stream flow distinctly. Flash flooding is a
surprise event whereas above average flow over longer periods of time might be
responded to through behavioral modification.
Methods
The range of nest initiation times for the years 1991, 1992, 1994 and 1996
cover the months of April, May and June. The data points for Morse Creek in
1993 were left out because of the limited time span. An index was developed as
percentages for each river for each year. The rivers (Duckabush, Hoh, Queets and
Quinault) are indexed to reduce the skewing of data of the three high flow rivers
against the much lower flowing Duckabush River.
39
Date
5/ 1/91
5/2/91
5/3/91
514191
515191
516191
5/7/91
5/8/91
5/9/91
5/ 10/91
5/ 11/91
5/12/91
5/ 13/91
5114191
5115191
5116/91
5/ 17/91
5118191
5119191
5/20/91
5/21 /91
5/22/91
5123191
5124191
5125191
5/26191
5/27/91
5/28/91
5/29191
5/30/91
5131191
6/ 1/91
612191
613/91
6/4191
615/91
6/6191
617191
6/8/91
619191
6110/91
6/ 11/91
61 12/91
Julim ~
12 1
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
14-0
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
Date
4/17/92
4i 18/92
4/ 19/92
4i20/92
4i2 1/92
4122/92
4123/92
4124192
4125/92
4126192
4127/92
4128/92
4129/92
4i30/92
511192
5/2/92
5/3/92
514192
515192
516192
517192
5/8/92
5/9/92
5/ 10/92
5111/92
5/12/92
5/ 13/92
5114192
5115192
5/ 16/92
5117192
5/ 18/92
5/19/92
5/20/92
5/21/92
Julim ~
108
109
110
I II
112
11 3
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
Date
4121/94
-l/22/94
4/23/94
4i24194
4125194
4126/94
4127/94
4128/94
4129/94
4130/94
511/94
5/2/94
513194
514194
515194
516194
517194
5/8/94
519194
5110194
5/ 11194
5112/94
5' 13194
5114194
5115194
5116194
5117194
5/ 18/94
5119194
Juli.an #
111
11 2
113
114
115
11 6
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
Date
4/12/96
4i 13/96
4114196
4i 15l96
4116196
41 17/96
4/18/96
4119/96
4120196
4121/96
4/22/96
4123/96
4/24196
4125/96
4/26/96
4127196
4128/96
4129/96
4/30/96
5/1196
5/2/96
5/3/96
5/4196
515196
5/6/96
517196
518196
519196
5110196
5111196
5112196
5/ 13/96
5/14196
5/ 15/96
5/ 16/96
5/ 17/96
5/ 18/96
5/19/96
5/20/96
5121196
5/22/96
5/23/96
5/24196
5/25/96
5/26196
5/27/96
5/28/96
5/29/96
5/30/96
5/31/96
6/ 1/96
612/96
613196
614196
615/96
6/6/96
617196
618/96
619196
43
5/22191
142
35
5/4192
125
29
514194
125
6/10/96
6111/96
6/ 12/96
6/ 13/96
63
5/ 13/96
Julim #
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
1.34
N~ofciayl
Mean
Table 2. Range of nest initiation dates and corresponding Julian dates for 1991. 1992. 1994 and 1996 (N.
Perfido 1997).
The indexed columns of data were correlated with nest initiation dates
transformed into a binary code of, 0 = not nesting and 1 = nesting. The correlation
measures the relationship between two sets of data scaled to be independent of the
unit of measure. The correlation is the covariance of the two data sets divided by
the product of their standard deviation (Microsoft Excel 1994).
Results
There is little correlation between the dates of nest initiation and the daily
stream flow of these rivers (a = 0.05). The following are the correlation
coefficients by year; 1991:
r2 = -0.1 O;
1992:
r2 = 0.09;
1994:
r2 = -0.05;
1996:
r2 =
0.12.
Discussion
There were no highly unusual daily flow events that can be correlated to
the range of nesting times during the years that were compared. The variability in
the signs of the correlation coefficients indicates that not only are the data weakly
correlated, but that there are other key variables influencing nest initiation timing.
This indicates the sheltered nature of the riparian hydrological regime on the
Olympic Peninsula. In the management of the resources benefiting the Harlequin
duck the breeding grounds used on the Olympic Peninsula appear to be more
favorable than the Rocky Mountains that are influenced in the spring, particularly
April and May, by snow melt run-off.
The limitations of the data points for the range of nest initiations was again
a problem in the strength of the conclusions that can be drawn from this study.
41
More data points could provide for a better relationship between the average daily
stream flow and the timing of nesting activity.
42
streams without Harlequins. The comparison was done for the categories of Pools
and Riffles (Tables 3 and 4). The null hypothesis is that there is no difference
between the streams with and without Harlequin ducks. A Mann-Whitney test was
used with a= 0.05, a two-tailed distribution and unequal variance.
Stream Name
Sample date
Bugs/M"
RANK
Habitat type
Stream ID
with
02-Aug-94
3942.40
10
POOL
WA837S
04-Oct-94
4682.50
POOL
WA858S
7
WA017S
29-Aug-95
2906.40
13
POOL
WA016S
3 l-Aug-95
POOL
9065.00
3
21-Jul-94
WA861S
PYSHTCR.
1818.00
17
POOL
WA840S
TRB QUIN AULT R.
28-Jul-94
4063.50
POOL
8
03-Aug-94
POOL
WA850S
WF HOQUIAM R.
5382.10
5
WA838S
l l-Aug-94
11
POOL
ZIEGLER CR.
3713 .70
WA848S
21-Sep-94
POOL
CAMP CR.
1275.60
20
WA840S
19-Oct-94
2357.40
27
POOL
TRB QUINAUL TR.
20-Oct-94
9647.50
POOL
WA861S
PYSHTCR.
2
WA0l IS
12-Jul-95
4
POOL
COOK CR.
5782.40
POOL
WA007S
COAL CR.
01-Aug-95
1614.60
18
02-Aug-95
12
POOL
WA009S
WEST TWIN CR.
3002 .00
WA840S
03-Aug-95
I
POOL
TRB QUINAULTR.
15379.40
WA003S
NF CROOKED CR.
08-Aug-95
452.10
25
POOL
09-Aug-95
POOL
WA004S
TRB WF DICKEY
915 .00
22
I0-Aug-95
5220.70
POOL
WA0l8S
TRB CLOQUALLUM
6
l 7-Aug-95
PYSHTCR.
1851.50
16
POOL
WA861S
22-Aug-95
3991.70
POOL
WA028S
SF SKOKOMISH R.
9
24-Aug-95
457.50
24
PINE CR.
POOL
WA029S
2103 .10
05-Sep-95
15
POOL
WA019S
CLOQUALLUM CR.
26-Sep-95
1383.20
19
POOL
NFSALMONR.
WA089S
,
601.50
23
27-Sep-95
POOL
WA840S
TRB QUINAUL TR.
947.10
21
POOL
WA861S
28-Sep-95
PYSHTCR.
Table 3. Invertebrate density data of pool habitats for 1994 and 1995 (Washington State
Department of Ecology).
SALMONR.
DUCKABUSH R.
NF SATSOP R.
NF SATSOP R.
without
44
Stream Name
Sample date
Bugs/M'
RANK
02-Aug-94
8547.00
SALMON R.
04-Oct-94
9906.17
DUCKABUSH R.
29-Aug-95
NF SATSOPR.
11265.34
3 l-Aug-95
NF SATSOP R.
12624.51
20-Jul-94
SF PYSHTR.
1230.20
21-Jul-94
PYSHT R.
3697.50
28-Jul-94
TRB QUINAULT R.
3950.50
03-Aug-94
WF HOQUIAM R.
1639.90
DEADF ALL CR.
3 l-Aug-94
2552.70
CAMP CR.
21-Sep-94
917.10
26-Sep-94
KIMTA CR.
510.80
THREE PRUNE CR.
27-Sep-94
961.40
TRB QUINAUL TR.
l 9-Oct-94
1267.50
PYSHT R.
20-Oct-94
851.50
COOK CR.
12-Jul-95
5220.70
COAL CR.
0l-Aug-95
5503.20
WEST TWIN CR.
02-Aug-95
1449.10
TRB QUIN AULT R.
03-Aug-95
3218.50
NF CROOKED CR.
08-Aug-95
1677.40
TRB CLOQUALLUM
10-Aug-95
7001.70
PYSHTR.
l 7-Aug-95
1317.70
SF SKOKOMISH R.
22-Aug-95
4790.10
PINE CR.
24-Aug-95
1960.20
CLOQUALLUM CR.
05-Sep-95
1874.80
NFSALMONR.
26-Sep-95
2296.40
TRB QUINAUL TR.
27-Sep-95
1716.90
PYSHTR.
28-Sep-95
2422.00
Table 4. Invertebrate density data of riffle habitats for 1994
Department of Ecology).
Habitat type
Stream ID
WA837S
RIFFLE
4
WA858S
RIFFLE
3
RIFFLE
WA017S
2
RIFFLE
WA016S
1
RIFFLE
WA860S
23
RIFFLE
WA861S
10
RIFFLE
WA840S
9
RIFFLE
WA850S
19
RIFFLE
WA856S
12
RIFFLE
WA848S
25
27
RIFFLE
WA835S
RIFFLE
24
WA836S
22
RIFFLE
WA840S
26
RIFFLE
WA861S
7
RIFFLE
WA0llS
RIFFLE
WA007S
6
20
RIFFLE
WA009S
11
RIFFLE
WA840S
18
RIFFLE
WA003S
5
RIFFLE
WA018S
21
RIFFLE
WA861S
RIFFLE
WA028S
8
15
RIFFLE
WA029S
16
RIFFLE
WA019S
14
RIFFLE
WA089S
17
RIFFLE
WA840S
RIFFLE
WA861S
13
and 1995 (Washington State
wit
with•
45
Results
There was no significant difference between the Pool categories in streams
with and without Harlequins (p<. l 0) so the null hypothesis is accepted. In the
Riffle category there was a highly significant difference between streams with
and without Harlequins (p<.0001) enabling the rejection of the null hypothesis.
Discussion
These results support the value of food resources in riffle habitats to the
distribution of Harlequin ducks. This has implications for maintaining water
quality, the integrity of a health riparian habitat and the collective integrity of all
the forces surrounding and supporting this ecosystem. Harlequin ducks are
apparently closely linked to their food source and dependent on its availability to
reside in a particular area.
Initially it was this author's intent to correlate hatching times to
invertebrate densities on the streams where the Harlequin duck is documented.
The invertebrate data and the hatching data are not extensive enough.
The factors influencing and limiting this analysis are the availability of
data points (four dates among two years for the streams with Harlequins) and the
time of year, which is later than the peak of the breeding season. Hatching occurs
in Washington in mid-May through July and it takes approximately 42 days to
fledge which puts the broods on the stream until September. The dates for the
invertebrate density data are August and very early October which are still
relevant, but limited. The availability of food
in August and October is not
46
necessarily an indicator of food availability earlier in the season. However, stream
habitat providing resources for the later larval emergences is likely to provide
similar high quality resources earlier in the season.
The usefulness of this exercise is the implications for more relevant ways
of collecting data in the future specifically for the purpose of understanding the
relationship between invertebrate densities, water quality and the support of
wildlife.
\
47
CHAPTER SIX: LAND MANAGEMENT, HUMAN ACTIVITIES AND
RECOMMENDATIONS
Introduction
The habitat setting provided for the Harlequin duck by the richness of the
Olympic Peninsula is beyond comparison.
It has a unique history both
geologically and as a result of the influence of European settlers and the U.S.
government. The following is a very short treatment of the history and current
issues surrounding the plight of the Harlequin duck on the Olympic Peninsula,
located in the Northwestern comer of the State of Washington.
Two
governmental domains are highlighted, the Olympic National Park and the
Olympic National Forest, because of their domination of the landscape and
influence on the management habitat of the Olympic Peninsula.
THE OLYMPIC PENINSULA
Olympic National Park
Olympic National Park is located on the Olympic Peninsula of
Washington State (Figure 3). The park boundaries encompass 908,720 acres of
contiguous area (Lyons and Satterfield 1992), and contain the isolated coastal
Olympic mountain range (McNulty 1996). The geological formation of this area
is impressive. The Olympic and the North Cascade Ranges originated through the
tectonic mechanisms of plate subduction, folding and faulting that created sharp
peaks.
This process began an estimated hundred million years ago and was
completed by several glacial stades culminating in the Vashon glacier.
This
48
glacier finished the formation of Puget Sound and essentially isolated the Olympic
Peninsula about two million years ago (Kruckeberg 1991 ).
Strait ofJuan De Fuca
Olympic National Park
Figure 3. The Olympic peninsula including Olympic National Park and the surrounding Ranger Districts
(U.S.Forcst Service).
4q
The ecology of the Olympic landscape is characterized primarily by large
amounts of precipitation (up to 200 in/yr.). There are approximately 600 miles of
hiking trails available to the public seasonally. The highest peak is nearly 8000'
rising directly from sea level.
The park provides a unique and superlative
opportunity to explore an area like no other in the world. Originally set aside to
essentially preserve the great herds of Roosevelt elk (Cervus elaphus), an
uncommonly large subspecies of elk, this mass of land is excellent Harlequin
breeding habitat because of its pristine nature (Gates ed. 1996).
The political boundaries of four counties overlap the area of Olympic
National Park: Clallam, Grays Harbor, Jefferson and Mason counties. The rivers
created from the formation of the Coast range, that are used by Harlequins include
Morse Creek, the Queets, Quinault, Hoh, Elwha, Duckabush, Dosewallips, South
Fork of the Skokomish, Hamma Hamma and the Wynoochie River.
Although Olympic National Park contains significant amounts of pristine
and virtually roadless Harlequin habitat on the Olympic Peninsula, there is a
considerable amount of area outside the park that is used for breeding and that
provides sufficient habitat. The ownership and stewardship of these other lands is
under the authority of such diverse groups and interests such as the National
Forest Service, the State of Washington Department of Natural Resources,
Simpson's Shelton Cooperative Sustained Yield Unit, several Indian Reservations
including the Quinault, Makah, the Skokomish, and private citizens (Olympic
50
National Forest Plan 1993). The management of these lands is based on varied
and wholly different philosophies of land use.
These
differences are
counterproductive and affect the uniform management of ecosystems for the
health and diversity of plant and animals species.
Olympic National Forest
Olympic National Forest began as a Forest Reserve in 1897 and was
formally titled Olympic National Forest in 1905. It occupies a total of 632,000
acres, 447,000 of which are classified tentatively as suitable for timber production
(Olympic National Forest Plan 1993). Olympic National Forest surrounds
Olympic National Park (Figure 3). It is prized for its silvicultural productivity
and its economic potential. The history of the Olympic National Forest and its
evolution to its present state is a conglomeration of the maturing of management
philosophies that range from rapacious harvests to the initial stages of dominant
use zoning (Alverson, Kuhlman and Waller 1994).
The use of Olympic National Forest has been dominated by silvicultural
development, which generally threatens the Harlequin duck. However, other
values managed for in this vast expanse of habitat can benefit the Harlequin.
Some of these values include scenery, recreation, water quality and wildlife
habitat.
The potential designation of Wild and Scenic Rivers provided for under
the Wild and Scenic Rivers Act of 1968 for the Dosewallips, Duckabush, main
51
stem and West Fork of the Humptulips, Hoh, Bogaciel, and Soleduck rivers
should not be overlooked in supporting the interests of the Harlequin duck.
Additional rivers described in the "Nationwide Rivers Inventory" under the Wild
and Scenic Rivers Act are the three main branches of the Calawah, the Dungeness,
Gray Wolf, Big Quilcene, Hamma Hamma, Skokomish, South Fork Skokomish,
Wynoochee, East Fork Humptulips, Quinault, and Elwha rivers. The majority of
these rivers support Harlequins and when listed will also benefit this species
(Olympic National Forest Plan 1993).
The rest of this chapter will address the historic and current human
activities on the Olympic Peninsula, the influence of riparian ecology, some
general and specific information about Harlequin duck production along the
riparian ecosystem some management issues and concerns and some final
recommendations from the study that went into creating this paper.
HUMAN ACTIVITIES
Historic Events
Riparian systems and climate are essential to the Harlequin on the
Olympic Peninsula. The impact of humans with their political boundaries and
land use practices has reduced the availability of good breeding habitat.
The
tension between the Forest Service and the Park Service began as a theoretical
argument of conservation (U.S. Forest Service) versus preservation (U.S. Park
Service) over one hundred years ago when president Grover Cleveland was given
52
the congressional go ahead to preserve forest lands. That tension has persisted to
this day on the Olympic Peninsula as a political battleground of land use versus
biological integrity (McNulty 1996).
Olympic National Park was created on June 29, 1938 by Franklin D.
Roosevelt after a long struggle with the politically powerful timber industry and
the Forest Service. It was set aside originally as Mount Olympus National
Monument in 1909 by the power of Theodore Roosevelt. The timber industry's
attempt to harvest the land as soon as possible before the momentum of
protectionism became strong delayed the process of creating a National Park and
allowed for the loss of a great deal of indigenous habitat that has not regenerated.
The Olympic Peninsula is a sanctuary of temperate rain forest catchments. The
most intact and pristine reaches of these catchments exist within the Olympic
National Park. The furious competition between the Forest Service and the Park
Service cannot be underestimated in the goal of promoting pristine habitat for the
Harlequin. Each entity has its own goals and ideals, which create competition for
natural, undisturbed habitat (McNulty 1996).
Current Threats and Management
The Harlequin duck is a game species and an ecological indicator species.
It is made clear in the writings of Ruggiero et al. (1988) that the preferences of a
species should be weighted equally or better with those components of habitats
considered requirements. Preferences give a species the ability to persist through
53
time because preferences provide flexibility in the selection of habitat.
The complexity of defining components, requirements and preferences of
habitat is understated in much of the literature about the Harlequin duck.
Understanding the various details of habitat requirements and preferences
provides for the more accurate use of dependency as a conceptual framework
rather than a strict checklist of habitat features that become standard in every
management plan. For the Harlequin this means that the variations in each
ecotype should be taken into consideration when designing management goals
and guidelines rather than making broad assumptions about the species based on
research and observations made of separate populations.
Human caused threats are the primary focus of habitat management,
proposed solutions and current policy. These threats span the entire habitat of the
Harlequin. On the coast, they face the devastation of oil spill contamination, over
hunting, encroachment of shoreline development and other commercial activities.
On the streams, they are confronted with the destruction of riparian areas and
degradation of watershed stability and stream flow regime by mining, roads or
timber harvest. Disruption in the form of inundation or elimination of breeding
habitat by river impoundment and diversion, and disturbance by recreational river
users and hikers in breeding areas are activities of concern in the effort to manage
and protect the Harlequin duck (Cassirer 1991; Clarkson 1992; Genter 1993;
Goudie 1996; Hunt 1993; Wallen 1987; Status 1993).
54
that human activity can have when they alter to the active river channel. For
example, some commercial and recreational activity increases overland flow in
the riparian ecosystem which can potentially have a negative effect on the
Harlequin ducks during their breeding season.
Both state and federal regulations impact the management of the Harlequin
duck.
However, the most critical and influential implementation of these
regulations is at the local level. The rivers used by the Harlequins empty into the
four counties and the management of wildlife is determined by political
boundaries and regions, thus the determination of important habitat features must
be collectively determined and policy agreed upon by people with differing values
and priorities.
Management interests are diverse and sometimes the influences of
resource management are not evident. The most clear examples of this are from a
state and federal regulation that impact the habitat of the Harlequin. At the state
level the mapping and designation of the Harlequin under Priority Habitat and
Species gives land owners and managers the opportunity to take the Harlequin
duck into consideration under the Washington Growth Management Act (1990)
(WDFW-PHS 1991).
At the Federal level designation of the Harlequin as a
Sensitive Species by the Forest Service in some regions and the regard provided
for by the National Environmental Policy Act in the development of habitat gives
some leverage to the protection of this species.
56
The conservation of the Harlequin duck under the Endangered Species Act
was a missed opportunity. The designation of this species as Category 2 was an
important sanctioned device that is no longer an option for managing the
conservation of the Harlequin as long as its status is inactive.
Recommendations
The impetus of this paper was to make a critical assessment of the nature
of information and management practices regarding the Harlequin duck on the
Olympic Peninsula and to come up with some original conclusions about this
species. The largest issue in the specific goals of this paper was the lack of data
for analysis. The stream habitat is invaluable to the Harlequin duck. The
conclusiveness of the data and analysis in this paper is weak but relevant.
Investigation Recommendations
Stream flow data should be collected daily during the breeding season
from areas on the streams where this species is actually seen. Analyzing the
stream flow data from the U.S. Geological Survey is interesting and provides
broad information at the level of the watershed. However to get more resolution
for the understanding of the influences of stream flow on breeding activity,
gauging of stream fluctuation on specific breeding streams is critical.
Brood survey data should be collected more often to provide increased
data points within years and across areas. Additional time spent observing and
surveying females with broods will provide increased information and
57
opportunities to see more birds. This kind of data collection will provide
information on habitat utilization, timing and activity in the breeding habitat and
give a better indication of production on the breeding grounds. Arrival on the
breeding grounds, nesting and breeding observations are also important for the
evaluation of the Harlequin duck as an indicator species, a Priority Habitat
Species, a Species of Special Concern and a potential candidate for listing under
the Endangered Species Act.
Further data on food utilization are necessary. This involves developing a
non-lethal means of collecting gizzard contents plus doing benthic invertebrate
sampling in the exact locations where the birds are feeding. This data will provide
critical and fundamental biological knowledge currently unavailable for this
population of Harlequin ducks.
These goals could be achieved with well placed gauging devices on the
stream, more technical support in surveying the streams that are used by
Harlequins during their breeding season and increased awareness by habitat
professionals and the outdoor public.
Refinements of benthic invertebrate data collection would include specific
locations, less variable kick samples (at this point the variation is from one to
eleven kicks per sample; G. Merritt, pers. comm. 5/9/97), and a compositional
evaluation of species in order to infer what might be eaten by Harlequins on the
streams. Furthermore, invertebrate collection dates should be more frequent
58
during reproduction events such as arrival on the stream, nesting and hatching.
Management Recommendations
Known Harlequin breeding areas should be considered sensitive to
modification and impact during the times when the species is actually present.
Reducing impacts on the stream environment through education and limited
degradations from recreation and resource extraction are priority concerns in the
management and conservation of the Harlequin duck on the Olympic Peninsula.
Although this species is vulnerable in its maritime habitat because of
oilspills and other types of hapless environmental degradation, the nature of its
existence in the freshwater environment and the management of this species along
the stream should not be diminished by the imbalance in current practices. There
is not so much a lack of study or information in some cases but a lack of support
from the administration to accomplish the necessary analysis by the Washington
State Department of Fish and Wildlife.
Consistent with other findings and studies the state of Washington must be
conscious of the impacts of resource extraction from areas adjacent to the
breeding streams, overuse and alteration of the structure and hydrological
processes of relevant riparian areas.
59
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