Individual covariation in life-history traits: Seeing the trees despite the forest
E. Cam, W.A. Link, E.G. Cooch, J. #NAME? Monnat, E. Danchin
2002, American Naturalist (159) 96-105
We investigated the influence of age on survival and breeding rates in a long-lived species Rissa tridactyla using models with individual random effects permitting variation and covariation in fitness components among individuals. Differences in survival or breeding probabilities among individuals are substantial, and there was positive covariation between survival and...
Variation in survivorship of a migratory songbird throughout its annual cycle
T. Scott Sillett, Richard T. Holmes
2002, Journal of Animal Ecology (71) 296-308
1. Demographic data from both breeding and non-breeding periods are needed to manage populations of migratory birds, many of which are declining in abundance and are of conservation concern. Although habitat associations, and to a lesser extent, reproductive biology, are known for many migratory species, few studies have measured survival...
Conditions and limitations on learning in the adaptive management of mallard harvests
Fred A. Johnson, W. L. Kendall, J.A. Dubovsky
2002, Wildlife Society Bulletin (30) 176-185
In 1995, the United States Fish and Wildlife Service adopted a protocol for the adaptive management of waterfowl hunting regulations (AHM) to help reduce uncertainty about the magnitude of sustainable harvests. To date, the AHM process has focused principally on the midcontinent population of mallards (Anas platyrhynchos), whose dynamics...
A removal model for estimating detection probabilities from point-count surveys
G.L. Farnsworth, K. H. Pollock, J.D. Nichols, T.R. Simons, J.E. Hines, J.R. Sauer
2002, The Auk (119) 414-425
Use of point-count surveys is a popular method for collecting data on abundance and distribution of birds. However, analyses of such data often ignore potential differences in detection probability. We adapted a removal model to directly estimate detection probability during point-count surveys. The model assumes that singing frequency is a...
Wood Thrush movements and habitat use: Effects of forest management for Red-cockaded Woodpeckers
J. D. Lang, L.A. Powell, D.G. Krementz, M.J. Conroy
2002, The Auk (119) 109-124
We monitored adult and juvenile breeding-season movements and habitat use of radio-tagged Wood Thrushes (Hylocichla mustelina) at the Piedmont National Wildlife Refuge, central Georgia, USA. We investigated the effects that management for Red-cockaded Woodpeckers (Picoides borealis), thinning and burning >30 year old loblolly pine (Pinus taeda) habitat, had on Wood...
Determining the trophic guilds of fishes and macroinvertebrates in a seagrass food web
J.J. Luczkovich, G.P. Ward, James C. Johnson, R.R. Christian, D. Baird, H. Neckles, W.M. Rizzo
2002, Estuaries (25) 1143-1163
We established trophic guilds of macroinvertebrate and fish taxa using correspondence analysis and a hierarchical clustering strategy for a seagrass food web in winter in the northeastern Gulf of Mexico. To create the diet matrix, we characterized the trophic linkages of macroinvertebrate and fish taxa. present in Hatodule wrightii seagrass...
Demography of a population collapse: The Northern Idaho ground squirrel (Spermophilus brunneus brunneus)
P. W. Sherman, M.C. Runge
2002, Ecology (83) 2816-2831
We studied the demography of a population of Northern Idaho ground squirrels (Spermophilus brunneus brunneus) in Adams Co., Idaho. The population was completely censused yearly from 1987 to 1999, during which time it declined from 272 to 10 animals. The finite population growth rate, based on a Leslie matrix model...
Spatio-temporal dynamics of species richness in coastal fish communities
K. Lekve, T. Boulinier, N. C. Stenseth, J. Gjosaeter, J-M. Fromentin, J.E. Hines, J.D. Nichols
2002, Proceedings of the Royal Society B: Biological Sciences (269) 1781-1789
Determining patterns of change in species richness and the processes underlying the dynamics of biodiversity are of key interest within the field of ecology, but few studies have investigated the dynamics of vertebrate communities at a decadal temporal scale. Here, we report findings on the spado-temporal variability in the...
The effects of polychlorinated biphenyls (Aroclor 1242) on thyroxine, estradiol, molt, and plumage characteristics in the American kestrel (Falco sparverius)
M.J. Quinn, J.B. French, F.M.A. McNabb, M. A. Ottinger
2002, Environmental Toxicology and Chemistry (21) 1417-1422
The purpose of this experiment was to determine the effects of Aroclor 1242, a mixture of polychlorinated biphenyls (PCBs), on plumage characteristics and molt in the American kestrel, Falco sparverills. Several characteristics of plumage. including color and molt schedule, are modulated by hormonal signals and hence may be modified by...
Proposal for adaptive management to conserve biotic integrity in a regulated segment of the Tallapoosa River, Alabama, U.S.A
Elise R. Irwin, Mary C. Freeman
2002, Conservation Biology (16) 1212-1222
Conserving river biota will require innovative approaches that foster and utilize scientific understanding of ecosystem responses to alternative river-management scenarios. We describe ecological and societal issues involved in flow management of a section of the Tallapoosa River (Alabama, U.S.A.) in which a species-rich native fauna is adversely affected by...
Scaling in sensitivity analysis
W.A. Link, P.F. Doherty Jr.
2002, Ecology (83) 3299-3305
Population matrix models allow sets of demographic parameters to be summarized by a single value λ, the finite rate of population increase. The consequences of change in individual demographic parameters are naturally measured by the corresponding changes in λ; sensitivity analyses compare demographic parameters on the basis of these changes....
A hierarchical analysis of population change with application to Cerulean Warblers
W.A. Link, J.R. Sauer
2002, Ecology (83) 2832-2840
Estimation of population change from count surveys is complicated by variation in quality of information among sample units, by the need for covariates to accommodate factors that influence detectability of animals, and by multiple geographic scales of interest. We present a hierarchical model for estimation of population change from the...
Narrowing historical uncertainty: probabilistic classification of ambiguously identified tree species in historical forest survey data
D.J. Mladenoff, S.E. Dahir, E.V. Nordheim, L.A. Schulte, G.R. Guntenspergen
2002, Ecosystems (5) 539-553
Historical data have increasingly become appreciated for insight into the past conditions of ecosystems. Uses of such data include assessing the extent of ecosystem change; deriving ecological baselines for management, restoration, and modeling; and assessing the importance of past conditions on the composition and function of current systems....
Estimating state-transition probabilities for unobservable states using capture-recapture/resighting data
W. L. Kendall, J.D. Nichols
2002, Ecology (83) 3276-3284
Temporary emigration was identified some time ago as causing potential problems in capture-recapture studies, and in the last five years approaches have been developed for dealing with special cases of this general problem. Temporary emigration can be viewed more generally as involving transitions to and from an unobservable state,...
Using Christmas Bird Count data in analysis of population change
J.R. Sauer, W.A. Link
2002, American Birds 10-14
The scientific credibility of Christmas Bird Count (CBC) results depend on the development and implementation of appropriate methods of statistical analysis. The key to any successful analysis of CBC data is to begin with a careful review of how the limitations of the data are likely to influence...
FrogwatchUSA
Sam Droege
2002, People, Land, and Water (9) 35-35
full text: Frogs and toads are perhaps the most approachable and available of all our wildlife. In many, if not most places, they are abundant. In wetter parts of the East, almost anyone outside on a warm rainy night in spring will hear their dream-like calls, bellows,...
Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck
P.S. Barboza, Dennis G. Jorde
2002, Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology (172) 419-434
We compared food intake, body mass and body composition of male and female black ducks (Anas rubripes) during winter (January-March). Birds were fed the same complete diet ad libitum on consecutive days each week without fasting (control; nine male; nine female) or with either short fasts (2 day.week-1; nine...
Producing progeny from endangered birds of prey: Treatment of urine-contaminated semen and a novel intramagnal insemination approach
J.M. Blanco, G.F. Gee, D.E. Wildt, A.M. Donoghue
2002, Journal of Zoo and Wildlife Medicine (33) 1-7
Wild raptors brought into an ex situ environment often have poor semen quality that is further compromised by urine contamination. Generally, it is believed that in birds, artificial insemination into the cloaca or caudal vagina of females requires large doses of high-quality spermatozoa to maximize fertility. In an effort to...
Using high hydraulic conductivity nodes to simulate seepage lakes
Mary P. Anderson, Randall J. Hunt, James T. Krohelski, Kuopo Chung
2002, Groundwater (40) 117-122
In a typical ground water flow model, lakes are represented by specified head nodes requiring that lake levels be known a priori. To remove this limitation, previous researchers assigned high hydraulic conductivity (K) values to nodes that represent a lake, under the assumption that the simulated head at the nodes...
Identification and synthetic modeling of factors affecting American black duck populations
Michael J. Conroy, Mark W. Miller, James E. Hines
2002, Book, Wildlife Monographs
We reviewed the literature on factors potentially affecting the population status of American black ducks (Anas rupribes). Our review suggests that there is some support for the influence of 4 major, continental-scope factors in limiting or regulating black duck populations: 1) loss in the quantity or quality of breeding habitats;...
The use of resighting data to estimate the rate of population growth of the snail kite in Florida
V.J. Dreitz, J.D. Nichols, J.E. Hines, R.E. Bennetts, W.M. Kitchens, D.L. DeAngelis
2002, Journal of Applied Statistics (29) 609-623
The rate of population growth (lambda) is an important demographic parameter used to assess the viability of a population and to develop management and conservation agendas. We examined the use of resighting data to estimate lambda for the snail kite population in Florida from 1997-2000. The analyses consisted of (1)...
Test for age-specificity in survival of the common tern
I.C.T. Nisbet, E. Cam
2002, Book chapter, Statistical analysis of data from marked bird populations
Much effort in life-history theory has been addressed to the dependence of life-history traits on age, especially the phenomenon of senescence and its evolution. Although senescent declines in survival are well documented in humans and in domestic and laboratory animals, evidence for their occurrence and importance in wild animal...
Approaches for the direct estimation of lambda, and demographic contributions to lambda, using capture-recapture data
J.D. Nichols, J.E. Hines
2002, Book chapter, Statistical analysis of data from marked bird populations
We first consider the estimation of the finite rate of population increase or population growth rate, lambda sub i, using capture-recapture data from open populations. We review estimation and modelling of lambda sub i under three main approaches to modelling open-population data: the classic approach of Jolly (1965) and...
Model-based estimation of individual fitness
W.A. Link, E.G. Cooch, E. Cam
2002, Book chapter, Statistical analysis of data from marked bird populations
Fitness is the currency of natural selection, a measure of the propagation rate of genotypes into future generations. Its various definitions have the common feature that they are functions of survival and fertility rates. At the individual level, the operative level for natural selection, these rates must be...
Random effects and shrinkage estimation in capture-recapture models
J. Andrew Royle, W.A. Link
2002, Book chapter, Statistical analysis of data from marked bird populations
We discuss the analysis of random effects in capture-recapture models, and outline Bayesian and frequentists approaches to their analysis. Under a normal model, random effects estimators derived from Bayesian or frequentist considerations have a common form as shrinkage estimators. We discuss some of the difficulties of analysing random...
