morrison - wildlife-habitat relationships - concepts and applications 3e (island press, 2006)

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Wildlife–Habitat Relationships
Wildlife–Habitat Relationships
Concepts and Applications
Third Edition
Michael L. Morrison
Bruce G. Marcot

R. William Mannan
Washington • Covelo • London
Copyright © 2006 Michael L. Morrison, Bruce G. Marcot, R.William Mannan
All rights reserved under International and Pan-American Copyright Conventions. No part of this book
may be reproduced in any form or by any means without permission in writing from the publisher:
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I
SLAND PRESS is a trademark of The Center for Resource Economics.
Library of Congress Cataloging-in-Publication data.
Morrison, Michael L.
Wildlife-habitat relationships : concepts and applications / by Michael L. Morrison, Bruce G. Marcot,
and R. William Mannan. — 3rd ed.
p. cm.
Includes bibliographical references.
ISBN 1-59726-094-0 (cloth : alk. paper) — ISBN 1-59726-095-9 (pbk. : alk. paper)
1. Habitat (Ecology) 2. Animal ecology. I. Marcot, Bruce G. II. Mannan, R. William. III. Title.
QH541.M585 2006
591.7—dc22
2006009619
British Cataloguing-in-Publication data available.
Printed on recycled, acid-free paper
Design by (to come)
Manufactured in the United States of America
10 9 8 7 6 5 4 3 2 1
Contents
List of Figures, Tables, and Boxes ix
Preface xvii
About the Third Edition xxi
Acknowledgments xxv
Part I Concepts of Wildlife–Habitat Relationships 1

1The Study of Habitat: A Historical and Philosophical Perspective 3
2The Evolutionary Perspective 15
3The Habitat, Niche, and Population Perspectives 43
Part II The Measurement of Wildlife–Habitat Relationships 129
4The Experimental Approach in Wildlife Science 131
5Measuring Wildlife Habitat: What to Measure and How to Measure It 151
6Measuring Wildlife Habitat: When to Measure and How to Analyze 182
7Measuring Behavior 220
8Habitats through Space and Time: Heterogeneity and Disturbance 254
9Wildlife in Landscapes: Populations and Patches 282
10 Modeling Wildlife-Habitat Relationships 320
Part III The Management of Wildlife–Habitat 377
11 Managing Habitat for Animals in an Evolutionary and Ecosystem Context 379
vii
12 The Future: New Initiatives and Advancing Education 417
Afterword 443
Glossary 447
About the Authors 451
Author Index 453
Subject Index 473
Contents
viii
Figures,Tables, and Boxes
Figures
Figure 2.1 Possible maximum extent of Pleistocene glaciation in the
Northern Hemisphere 17
Figure 2.2 Hemlock pollen abundance in Wisconsin and Michigan lake sediments
showing westward movement of hemlock range limit over past 6000 years 18
Figure 2.3 Correlation between archaeological episodes and generalized climatic and
vegetational changes, 12,000 BC–AD 250 20

Box Figure 2.1 Model sequence showing effects of glacial flow and ebb on adaptation and
evolution of hypothetical ancestral wood warbler and its descendents 23
Box Figure 2.2 Breeding and wintering ground distribution of members of black-throated
green warbler (Dendroica virens) superspecies complex 24
Box Figure 2.3 Abundances (percentages) of four species of microtine rodents and of total
microtines (including those unidentifiable to species) recovered from 15
fossil excavation levels, New Mexico 25
Figure 2.4 Distribution of extant pikas (Ochotona princeps) and late
Pleistocene–Holocene fossil records in western North America 27
Figure 2.5 Temporal changes in relative abundance of ungulate, carnivore, and
small-mammal remains in archaeological collections from the lower Snake
River, southeastern Washington 28
Figure 2.6 Causal relationships between food web structures, successional state, and
ecosystem functions 33
Figure 2.7 Factors influencing population dynamics and community structure in
natural systems 35
ix
Figure 2.8 Partial food web depicting relationships between lizards (Leiocephalus and
Anolis) and various web components 36
Figure 2.9 Patterns of colonization and general population trends for moose in relation
to loss of grizzly bears and wolves, Jackson Hole region, Greater Yellowstone
Ecosystem, 1840s–1990s 37
Box Figure 3.1A Four hypotheses on plant species distributions along environmental
gradients 47
Box Figure 3.1B Actual distributions of plant species populations along environmental
gradients 47
Figure 3.1 The amount of edge proliferates with increasing fragmentation, due to the
increased edge per unit area as the number of patches increases, and as
individual patches become, on average, more linear or more irregular
in shape 49

Figure 3.2 Foliage height diversity (FHD) versus bird species diversity (BSD) 50
Figure 3.3 Number of wildlife species associated with successional stages in a
mixed-conifer community 51
Figure 3.4 Model of interactions between mammalian herbivores and plants 52
Figure 3.5 Various activities associated with grazing or browsing animals and their
possible effects on plants 53
Figure 3.6 Stand measure of percentage of coarse woody debris cover calculated
separately for capture plots (trap locations where voles were captured);
noncapture plots (trap locations chosen randomly out of all locations
where voles were not captured); and movement plots (minimum bounding
triangle around a vole trail), Montana 56
Figure 3.7 Limited sampling along a gradient in a habitat variable may produce a
positive (a), nonexistent (b), or negative (c) correlation with a species
response variable such as density 60
Figure 3.8 Generalized depiction of a species’ biological response to an environmental
gradient 62
Figure 3.9 Generalized depiction of two species’ biological responses to successional
forest stages 63
Figure 3.10 Mean density (n/40.5 – ha index), coefficient of variation (CV) of density
among replicate study plots, and percentage of occurrence (PO, percentage
of replicate study plots occupied) of (A) brown creepers (Certhia americana)
and (B) hermit warblers (Dendroica occidentalis) among five successional
stages of Douglas-fir (Pseudotsuga menziesii) forest in northwestern California 64
Figure 3.11 Cumulative number of terrestrial vertebrate species (amphibians, reptiles,
birds, and mammals) that use old-forest structural stages as a function of the
percentage of all other vegetation structural stages used, in the interior
Columbia River basin 66
Box Figure 3.2 Some patterns of spatial distribution of organisms 68
Figure 3.12 Three patterns of relations between annual exponential rate of change in
population and initial size of the population 80

Figures,Tables, and Boxes
x
Figure 3.13 Examples of empirical evidence supporting the inverse exponential pattern
of relations between changes in population size and initial population size,
expressed in two ways 82
Figure 3.14 An example of how inbreeding depression influences effective population
size, using the model for intergenic genetic drift presented in box 3.4 83
Figure 3.15 An example of an analysis of the effects of inbreeding depression and
population size on the viability of a hypothetical population with an
increasing trend (l = 1.24), an equal sex ratio, and an initial population set
(A) N
(s)
= 5 and (B) N
(s)
= 80 84
Figure 3.16 Classification of genetically determined variation for use in conservation
planning 85
Figure 3.17 Equilibrium population size and the distribution of individuals in
landscapes containing 0–100% low-quality habitat, where ≤30% of the
population selected low-quality habitat over high-quality habitat for
breeding 93
Figure 3.18 Current summer distribution of wrentits (Chamaea fasciata) in North
America based on mean bird counts per Breeding Bird Survey route,
1982–1996 94
Figure 3.19 Different dispersal distances needed to reduce negative characteristics of
natal habitat 95
Figure 3.20 The major threatening processes affecting birds, mammals, and plants 104
Figure 3.21 Land ownership and generalized elk movements from high-elevation public
land to lower-elevation private land, White River area, Colorado 107
Figure 3.22 Biological information and management objectives are often influenced by

political decisions in setting harvest levels 107
Figure 3.23 Probability of wildlife flushing with increasing perpendicular distance 111
Figure 4.1 Activities in the scientific method and common places where statistical tests
are employed 132
Figure 5.1 The hierarchical nature of habitat selection 156
Figure 5.2 Hierarchical description of habitat quality assessments. 157
Figure 5.3 An outline of the spatial scales at which ecological field studies are conducted 157
Figure 5.4 Effects of scale on study of patterns of habitat association 158
Figure 5.5 Coefficients of determination (r2 ´ 100) between similarity and distance
matrices based on avian, floristic, and physiognomic composition of eight
grassland study sites 161
Figure 5.6 Habitat variable sampling configuration used by Dueser and Shugart in their
study of small-mammal habitat use 175
Figure 5.7 Sampling scheme used by Reinert for snake locations 177
Figure 6.1 Use of a species of tree by two hypothetical animal species during “summer.” 183
Figure 6.2 Habitat selection by female black bears at two study areas in northern Maine
during fall (den entry on September 1), 1986–1988 184
Figure 6.3 The necessary sample size, n, as a function of mean density, m, for various
degrees of power, 1 – b,when sampling the Poisson distribution 190
xi
Figures,Tables, and Boxes
Figure 6.4 Influence of sample size on the stability of estimates and measurements of
bird-habitat characteristics 191
Figure 6.5 Schematic diagram of the scientific research elements that combined in a
synthesis to produce multivariate habitat analysis 195
Figure 6.6 Arcsine-transformed predation on artificial nests (n = 540) in 15 prairie
fragments regressed onto a natural log-transformed tract area (ln [size] and
ln[size]
2
) 197

Figure 6.7 Results of a principal components analysis of habitat variables associated
with capture sites of small mammals at La Picada, Chile 202
Figure 6.8 Principal component (PC) analysis of vegetation cover and snow conditions
on muskoxen and reindeer habitats, feeding sites, and craters on the northern
Seward Peninsula, Alaska, during late winter 202
Figure 6.9 Summary of the model-building procedure 206
Figure 6.10 Examples of how the extent, or range, of an environmental gradient from
which samples are taken can influence conclusions 207
Figure 6.11 Tentative model of a community in attribute space 211
Figure 6.12 Distribution of form scores showing separation of three leporid species,
southeastern Arizona, along two discriminant axes (DF 1 and DF 2) based
on 22 continuous habitat characteristics used in discriminant analysis 212
Figure 7.1 The hierarchy of sampling rules (determining who is watched and when) and
recording rules (determining how their behavior is recorded) 225
Figure 7.2 An example of scan sampling as used to study the foraging strategies of
common murres (Uria aalge) 228
Figure 7.3 Seasonal variation in the use of tree species, substrates, and foraging modes
by chestnut-backed chickadees (Parus rufescens) 234
Figure 7.4 A highly simplified transition matrix, analyzing the sequence shown above it,
which comprises only two different behavior patterns 245
Figure 8.1 A “zoning map” of ecological scale and species assessment, plotting spatial
area against time (note log axes) 260
Figure 8.2 A “zoning map” of ecological scale and ecosystem management issues,
plotting spatial area against time (note log axes) 261
Figure 8.3 Effects of species mobility, physical heterogeneity of the environment, and
competition on species diversity 266
Figure 8.4 An example of how two indices of habitat patch pattern can be highly
correlated 269
Figure 8.5 Four types of disturbance shown by degree, or intensity, and geographic area
affected 277

Figure 9.1 Species–area relations of isolated and nonisolated areas 298
Figure 9.2 Faunal collapse of Nairobi National Park as predicted by five faunal collapse
species models 299
Figure 9.3 Basic elements of the consequences of habitat isolation and subsequent
faunal relaxation (species loss) to new equilibrium levels of diversity 300
Figures,Tables, and Boxes
xii
Figure 10.1 Causes and correlates: four increasingly complex and realistic scenarios of
wildlife–habitat relationships 323
Figure 10.2 Example of a path analysis that partitions the various factors accounting for
variation in public satisfaction with quality deer management (QDM) 325
Figure 10.3 Number of articles on models or modeling published in all journals by the
Wildlife Society (TWS) and the Ecological Society of America (ESA), by
decade, 1954–2003 331
Figure 10.4 Example of a STELLA model 341
Figure 10.5 Hypothetical example of a Bayesian belief network model 345
Figure 10.6 Hypothetical example of a decision tree designed to evaluate whether to
translocate a threatened wildlife population or acquire land for a reserve 346
Figure 10.7 Example of regression tree modeling of three categories of species viability
risk levels predicted from life history and habitat use attributes, based a
sample set of 60 wildlife species in the Pacific Northwest of the United States 348
Figure 10.8 Example of the structure of a fuzzy logic model predicting density of
white-headed woodpecker (WHW; Picoides albolarvatus) territories, using
the NetWeaver fuzzy logic modeling shell 350
Figure 10.9 Example of a rule induction model called SARA (Species at Risk Advisor),
using the ID3 rule induction algorithm, of species viability risk levels
predicted from life history and habitat use attributes 352
Figure 10.10 Example of a neural network model of the presence and absence of 27 fish
species as a function of nine lake habitat variables 354
Figure 10.11 Example of a habitat map and its graph theory analog 356

Figure 11.1 Functional redundancy (number of species) of forest mammals in
Washington and Oregon, by selected category of key ecological function 393
Figure 11.2 An example of how patterns of the functional aspects of wildlife do not
necessarily correlate with patterns of habitat use 399
Figure 11.3 Changes in functional redundancy (number of all terrestrial vertebrate
wildlife species) from historic (early 1800s) to current (ca. 2000) time
periods, for the key ecological function (KEF) of soil digging 400
Box Figure 12.1 An envirogram depicting factors hypothesized to influence summer
abundance of brush mice (Peromyscus boylii) in the Sacramento Mountains
of southern New Mexico 427
Ta b l e s
Ta ble 1.1 Important U.S. legislation stimulating the study, preservation, or
management of animal habitat 8
Ta ble 2.1 Studies examining the potential influence of temperature change on the life
history of North American animals and plants 31
Ta ble 2.2 Dates of major Pleistocene and Holocene mammalian extinctions 37
Ta ble 3.1 Ecotone hierarchy for a biome transition area 48
xiii
Figures,Tables, and Boxes
Ta ble 3.2 Anticipated changes of management activities on successional state or
condition 54
Ta ble 3.3 Definitions and examples of key terms related to populations, species, and
systems and their importance for conservation 70
Ta ble 3.4 Some of the main ecological factors that affect the long-term viability of
populations 72
Ta ble 3.5 Types of extinction and their implications for conservation 73
Ta ble 3.6 A classification of the migration status of wildlife species 97
Ta ble 3.7 Mappable elements of habitat distribution and pattern important to
maintaining metapopulations 114
Ta ble 3.8 Conditions of organisms, populations, and species warranting particular

management attention for conservation of biodiversity 116
Ta ble 5.1 Variables and sampling methods used by Dueser and Shugart in measuring
forest habitat structure 169
Ta ble 5.2 Structural and climatic variables used by Reinert in differentiating
microhabitats of timber rattlesnakes (Crotalus horridus) and northern
copperheads (Agkistrodon contortrix) 170
Ta ble 5.3 Hierarchic arrangement of ecological components represented by 43
measurements of the forest environment taken in conjunction with sampling
for the Del Norte salamander (Plethodon elongatus) 171
Ta ble 5.4 Average work accomplished in 30 minutes of field effort recording the
species and diameters of trees in an upland Ozark forest in Arkansas 174
Ta ble 6.1 Vegetational habitat variables and their mnemonics, used by Gotfryd
and Hansell 192
Ta ble 6.2 Classification of common statistical techniques 199
Ta ble 6.3 Eigenvectors for the significant components resulting from a principal
components analysis conducted on summer and winter vegetative
parameters 201
Ta ble 6.4 Summary of the first four principal components 203
Ta ble 6.5 Results of principal components analysis using weighted averages of eight
habitat variables for thirty-four bird species 203
Ta ble 6.6 Classification matrix derived from a discriminant function program showing
actual and predicted species (group) membership for singing male warblers
based on habitat use on the deciduous and nondeciduous tree sites. 209
Ta ble 6.7 Discriminant analysis of small mammal habitat use, western Oregon 210
Ta ble 7.1 Time budgets of loggerhead shrikes, in hours spent per activity 235
Ta ble 7.2 Cost of activity in loggerhead shrikes 237
Ta ble 7.3 Results of comparing usage and availability data when a commonly available
but seldom-used item (A) is included and excluded from consideration 247
Ta ble 8.1 Aspects and examples of scale at three levels of magnitude 258
Ta ble 8.2 Components of habitat heterogeneity in landscapes 263

Ta ble 8.3 Some indices of habitat heterogeneity 268
Ta ble 8.4 Effects of three types of disturbance on forest components 276
Figures,Tables, and Boxes
xiv
Ta ble 10.1 Criteria useful for validating wildlife–habitat relationship models 328
Ta ble 11.1 A hierarchic classification of key ecological functions of wildlife species 390
Ta ble 11.2 A taxonomy of patterns of key ecological functions (KEFs) of wildlife species
and communities, and how to evaluate them using a wildlife-habitat
relationships database 395
Ta ble 11.3 Classification of ecosystem services 403
Box Table 12.12 Precision and relative importance of ecological factors associated with
summer abundance (g/ha) of brush mice in the Sacramento Mountains,
New Mexico (1992–1994) 429
Ta ble 12.1 Desiderata for a more rigorous community ecology 432
Boxes
Box 2.1 Wood warbler occupation of North America as related to Pleistocene
geologic events 22
Box 2.2 Progression of four species of microtine rodents 25
Box 3.1 Whittaker’s four hypotheses on the distribution of plant species populations 46
Box 3.2 How distance can act to genetically isolate organisms and populations 67
Box 3.3 Population viability modeling and analysis 75
Box 3.4 Alternative ways of calculating effective population size, N
e
77
Box 4.1 What is a statistical interval and how should it be used in wildlife studies? 136
Box 6.1 How many samples are needed? 188
Box 9.1 Edge effects and changing perspectives 283
Box 9.2 Adaptive radiation of species complexes in island and continental settings 292
Box 9.3 Adaptive radiation of New Zealand lizards 294
Box 9.4 Some interesting kinds of habitat isolates 304

Box 10.1 Propagation of error in modeling wildlife-habitat relationships 329
Box 10.2 Bayesian modeling and wildlife habitat 343
Box 10.3 Using decision trees for conservation planning 347
Box 11.1 What is wildlife? 381
Box 11.2 Thinking green in an urban environment: City greenbelts as natural
environments in urban landscapes 386
Box 12.1 Envirograms: Templates for modeling wildlife–habitat relationships 427
Afterword box
Primary elements and assumptions of a resource planning scenario designed
for long-term sustainability of habitats for wildlife and humans. 445
xv
Figures,Tables, and Boxes
Preface
When we published our first edition of this book
in 1992, the world population stood at a bit over
5.44 billion people and was increasing at an an-
nual growth rate of 1.48%, adding 81,404,054
people to the planet annually, according to the
United States Census Bureau. When we pub-
lished our second edition in 1998, there were
over 5.92 billion people, and although the an-
nual growth rate had dropped slightly to 1.31%,
it was still adding 78,308,546 people annually. As
we completed this, our third edition, in early
2005, the planet was bearing over 6.47 billion of
us, with an annual rate of increase of 1.14%, or
74,629,207 people. Concomitantly, just in this
14-year wink of an ecological eye, we have seen
striking evidence of continued loss or degrada-

tion of the scarcest natural environments, in-
cluding tropical coral reefs, mangrove swamps,
ancient forests, and native grasslands, while ur-
ban, suburban, agricultural, and degraded lands,
and lands dedicated solely to intensive resource
production, continue to spread.
We w ish for optimism but cannot ignore the
crises in wildlife conservation that seem to con-
front us everywhere these days. Changes in re-
gional and global climates continue to challenge
our understanding but cry for action. There are
crises of academia as essential expertise in basic
taxonomy and systematics has itself become a
moribund species; how crucial these skills are,
for if we cannot name and catalog organisms, we
cannot hope to document and quantify trends
and mobilize action to stem extinctions, local
and global. Other writers have despaired of how
few conservation biologists these days spend
much time in the field, and of how natural his-
tory as an empirical science and lifestyle seems
to be increasingly forgotten. Perhaps the greatest
crisis is what Robert Michael Pyle (1992) wrote
of as “the extinction of experience,” a growing
personal alienation from nature and loss of inti-
macy with the very environment that sustains
us, for, as he wrote,“What is the extinction of the
condor to a child who has never known a wren?”
We speak of the “legacies”of ancient forests—
large old trees,snags, down logs, and organic ma-

terial to enrich tomorrow’s soils. As well, we need
to consider the legacies of our own knowledge
xvii
and expertise to help others understand and pro-
vide wildlife and habitats for tomorrow. Reliable
knowledge comes with rigor and scientific study.
However, knowledge without action is as fruitless
as never evolving from the primordial soup of ig-
norance in the first place.“Research,” as the Ore-
gon political columnist Russell Sadler (1991)
once said, “is a race between ignorance and irre-
versible consequences.”
While scientists struggle to understand the
relations between human-caused environmental
changes, biocomplexity, ecosystem resilience,
species viability, and resource sustainability, we
cannot lose sight of the astounding rapidity with
which all these changes are occurring, nor the
accelerated need to educate ourselves and others
on the effects of our daily living habits. More
than ever, we must all redefine ourselves as
perennial students of the planet, whether we are
senior managers, researchers, or academic stu-
dents in the traditional sense. There is far more
for us to learn than we ever can, as time for stabi-
lizing or restoring wildlife and their habitats has
already run out in portions of our wonderful
and crowded world. This is what has led us to
dedicate this third edition to wildlife students
everywhere, the corollary being that learning

and mutual education must never cease.
Let us quickly move beyond alarmism, for
that shuts off the lines of listening by those
publics, politicians, and purveyors we need to
reach. Instead, as a wildlife profession, we can as-
sert a positive vision of wildlife conservation
that builds on legacies of knowledge and ecosys-
tems alike.As our numbers grow, we can point to
incredibly bold new moves in wildlife conserva-
tion that beg respect and emulation. India,
which has surpassed 1 billion people since our
second edition was published, in an attempt to
save the last of its parks and wildlife communi-
ties has essentially outlawed clear-felling of
forests and most sport hunting, and has given
nontimber forest resources great economic and
social focus. China has instituted policies of
family size constraints and a massive reforesta-
tion program in many of their degraded and de-
sertified lands. The Nature Conservancy has suc-
cessfully run innovative programs of swapping
portions of national debt for conserving critical
natural areas in some developing countries. Ma-
jor ecosystem restoration programs have been
instituted, such as those in the Everglades of
Florida. Top predators—carnivores—have been
successfully reintroduced to Yellowstone Na-
tional Park and elsewhere. There now are more
national parks and sanctuaries, and more recov-
ery plans for threatened and endangered species

in place, than ever throughout the world.
Such positive steps toward wildlife and habi-
tat conservation include some extreme measures
taken literally in the face of collapsing ecosys-
tems and vanishing species, as well as more evo-
lutionary measures designed to better integrate
economies with conservation, such as through
burgeoning ecotourism and sustainable ecode-
velopment programs. Developed countries also
can learn much from conservation measures de-
signed to include participation and ownership
by local and native peoples, who often are most
in need of reliable and sustainable resources and
economic growth and stability.
In this way, wildlife conservation should not
be viewed as a pastime of the rich but as a plan
for the future for us all. A new vision for a near
future in which we truly provide for sustainable
resources, provide for ecosystem integrity, and
foster the health of our biosphere, likely will de-
mand the courage to seek and accept changes in
our daily resource use habits and even to shift
the very centers of what we value and how we
value what we use. We can employ such positive
visions, and successes like the ones cited above,
as hallmarks and templates to help further such
a future. It is not wildlife versus humanity, jobs
versus owls, today’s food versus tomorrow’s invi-
olate protected area that will foster participation
Preface

xviii
for a sustainable future. Nor will a sustainable
future be reached along a gap between the aca-
demically educated and the lay public. Only by
opening our minds and hearts and all becoming
students can we move there together.
The purpose of our first edition was to ad-
vance from the point where the many fine, but
introductory, texts in wildlife biology left off.
Through the second, and now this third, edition,
this purpose has not changed. We have further
developed this new edition to incorporate the
many new ideas that have come our way from
several sources. First, we took to heart the inde-
pendent reviews that appeared in scientific jour-
nals. Second, our friends and colleagues showed
us their hidden talents as book critics; we also at-
tended to these comments. Finally, we each have
tapped into new experiences and studies to pre-
sent the most current findings, concepts, and vi-
sions for future development in research and
management.
This book is intended for advanced under-
graduates,graduate students, and practicing pro-
fessionals with a background in general biology,
zoology, wildlife biology, conservation biology,
and related fields. An understanding of statistics
through analysis of variance and regression is
helpful, but not essential. Land managers will es-
pecially benefit from this book because of its em-

phasis on the identification of sound research
and the interpretation and application of results.
Our approach combines basic field zoology
and natural history, evolutionary biology, eco-
logical theory, and quantitative tools. We think
that a synthesis of these topics is necessary for a
good understanding of ecological processes, and
hence good wildlife management. We attempt to
draw on the best and recent examples of the top-
ics we discuss, regardless of the species involved
or its geographic location. We do concentrate on
terrestrial vertebrates from temperate latitudes,
with a bias toward North America, because this
is where much literature has been developed and
where our own experience has occurred. How-
ever, because it is the concepts that are impor-
tant, the specific examples are really of second-
ary importance. Hence our writing can be used
by anyone from any location. We did try, how-
ever, to bring in examples from amphibians, rep-
tiles, birds, and mammals (both large and
small), and from different ecosystems and loca-
tions, to help individuals from different back-
grounds better understand the application of
concepts to their particular interests.
We emphasize the need for critical evaluation
of methodologies and their applications in wild-
life research. Management decisions all too of-
ten are based on data of unknown reliability—
that is, from research conducted using biased

methods, low sample sizes, and inappropriate
analyses. We understand also that, all too often,
managers are faced with making decisions us-
ing unreliable or incomplete data. The general
dearth of monitoring, validation, and adaptive
management research forces a vicious cycle. This
does not need to—and should not—persist.
To aid both the student and the professional,
we have tried to explain fundamental concepts
of ecological theory and assessment so that the
use of more advanced technical tools is more
acceptable, more often sought, and more appro-
priately applied. Ultimately, the success of con-
servation efforts depends on gathering, analyz-
ing, and interpreting reliable information on
species composition, communities, and habitat.
We hope that this book encourages such rigor in
concept and practice.
Literature Cited
Pyle, R. M. 1992. Intimate relations and the extinction
of experience. In Left Bank #2: Extinction, 61–69.
Hillsboro, OR: Blue Heron Publishing.
Sadler, R. 1991. Paper presented at the New Perspec-
tives Conference, USDA Forest Service, Roanoke
VA ,December 3, 1991.
xix
Preface
About the Third Edition
The second edition forms the core of this new

work.We have revised much of the text, intro-
duced much new material in each chapter to
supplement that previously offered, and updated
reference citations throughout.
In Part 1, Chapters 1 through 3 cover central
concepts of wildlife–habitat relationships and lay
the foundation on which the rest of the book is
constructed. Chapter 1 discusses the historical
background and philosophical attitudes that
have shaped the wildlife profession and influ-
enced how research should be approached.
Chapter 2 reviews the evolutionary background
against which the current distribution, abun-
dance, and habits of animals developed. In this
edition, we defer discussion of keystone species
to a broader and updated discussion of “key eco-
logical functions” of species in Chapter 11.
Chapter 3 discusses habitat relationships from
the perspective of vegetation ecology and popu-
lation biology. In Chapter 3, we have updated
and substantially expanded our discussion of the
niche as it appeared in the second edition.
Specifically, we have developed how the study of
multiple limiting factors likely holds the key to
advancing our study of habitat relationships. We
still address population responses, and have ex-
panded our discussion of population viability,
genetics, metapopulation dynamics, and related
concepts.
In Part 2, Chapters 4 through 10 form the

heart of the book and cover measurement and
modeling of wildlife–habitat relationships.Chap-
ter 4 discusses fundamental approaches to study
design and experimental methodologies, review-
ing the philosophy of various ways of gaining re-
liable knowledge, and the challenges to conduct-
ing scientific investigations and having the result
be accepted in society.We have added new exam-
ples, and new subjects of concern about science
are now addressed including information theo-
retic versus traditional hypothesis testing, and
relativism. Chapters 5 and 6 review the many
methods that have been used to develop wildlife-
habitat relationships, including field methods,
data analysis, sampling biases, and data interpre-
tation. We re-organized Chapter 5 to more ex-
plicitly encompass analyses across spatial scales,
xxi
and have updated our discussions of methodolo-
gies to include the increasing use of new tech-
nologies. Chapter 6 also incorporates discussion
of multivariate statistics, which we have updated
with additional comments on methods and mis-
uses of the techniques. Although we do not delve
heavily into methods of multivariate analyses, we
think that we are more effective by emphasizing
the concept of multivariate analyses,proper sam-
pling methods, and interpretation of results. We
have also added new information on model se-
lection procedures,such as AIC.Chapter 7 covers

behavioral sampling and analysis in wildlife re-
search, and has been expanded to include more
information on the fundamental causes of an in-
dividual’s behavior. Chapters 8 and 9 review
characterization of patterns of habitat within
landscapes, and population responses, respec-
tively, including habitat fragmentation, study of
metapopulations, and landscape ecology, topics
that continue to be emphasized by researchers
and managers alike. Chapter 8 presents the ra-
tionale for a landscape-perspective of habitat re-
lationships, definition and classification of land-
scapes, basics of landscape ecology, concepts of
spatial and temporal scales in ecological study
and their implications for managing habitat in
landscapes, ways to depict and measure habitat
heterogeneity including habitat fragmentation,
and reviews disturbance ecology and manage-
ment implications; all material—concepts, sum-
mary of studies, and citations—has been
brought up to date since the previous edition.
Chapter 9 focuses on population response to
landscape conditions and patterns, and reviews
how researchers and managers have viewed wild-
life response to habitat edges, boundary effects,
and succession and climate; provides an updated
discussion of population viability, metapopula-
tion dynamics, and effects of population isola-
tion; updates discussions of biogeographic im-
plications of habitat isolation and patterns,

species–area relations; and discusses implication
for conserving and monitoring wildlife in het-
erogeneous environments, including utility of
habitat corridors. All of this material has been
updated since the last edition.Chapter 10 reviews
and updates the utility and development of wild-
life–habitat relationships models, including dis-
cussion of how to select models, depict uncer-
tainty, and implications of prediction errors and
model validity for research hypothesis-testing
and management decision making. Chapter 10
also updates discussions from the last edition
on traditional types of models, and presents a
new section on more recent, avant garde wildlife
habitat modeling approaches that draw from
fields of decision support, Bayesian statistics, and
various knowledge-based approaches only re-
cently being developed for wildlife habitat mod-
eling. The chapter also updates a discussion on
recent developments in various approaches to
modeling land allocations for habitat conserva-
tion and on recent results of model validation.
In Part 3, Chapters 11 and 12 cover manage-
ment of wildlife–habitat relationships.Chapter 11
introduces the topic of wildlife and habitat man-
agement in the context of ecosystem manage-
ment. We discuss and illustrate wildlife manage-
ment goals in an evolutionary and ecological
context, and provide all-new material and exam-
ples on a broad environmental and functional

approach, including an ecographic (mapping)
approach to evaluating and managing for key
environmental correlates, key ecological func-
tions, and key cultural functions of wildlife. We
newly discuss implications for conservation of
ecosystem services, thinking beyond wildlife
population viability in a community and ecosys-
tem context, and practical approaches to manag-
ing for evolutionary potential of wildlife. We
also provide an updated discussion of adaptive
management and review both failures and suc-
cesses in this area. Chapter 12 presents a frame-
work for advancing our understanding of wild-
life through modified approaches to habitat
About the Third Edition
xxii
relationships, raises a call for greater emphasis
on the synthetic field of restoration ecology, and
makes a plea for improvements to our educa-
tional system. We present this material partly as
a prescription, and partly as a “null model” on
which we can debate the best means of advanc-
ing our profession. In this edition we have re-
fined our recommendations on how wildlife and
habitat might be studied if we are to improve
our understanding of what determines distribu-
tion and abundance, and ultimately leads to the
recovery and preservation of species.
New to this edition is a brief glossary of key
terms that every wildlifer should know. The

book concludes, as did the second edition, with
an author index and a general subject index.
Developing this latest edition entailed our ex-
tensively reviewing a massive amount of recent
literature and discussing concepts, findings, and
approaches with many researchers and man-
agers. In one sense, little has changed since the
early 20th century; habitat is still the crux and
essential foundation for wildlife conservation,
although there continue to be rapid advances
in approaches to conceptualizing, measuring,
modeling, and managing habitat. We have tried
to keep pace with such advances in this edition
and have prioritized new and expanded discus-
sions on topics with the most promise for suc-
cessfully understanding and conserving wildlife
and habitats.
Lastly, in this volume we have again demon-
strated the robust, positive growth rate of new
editions, despite our wonderful editor’s decree
for density-dependent limits to growth. When
pressed, our answer is simply, “Knowledge
should be boundless.”
xxiii
About the Third Edition