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Accession Number 5001795

Title Determination, biological consequences, and modeling of sex-specific demographic

rates in declining, threatened, or endangered metapopulations

Project Description Proper management of animal populations requires an understanding of both population dynamics

and ecology, and more research that integrates population dynamics and ecological studies is

needed to identify the causal factors involved in population declines, recoveries, and viability. The

information being generated from such studies will allow managers 1) to identify species-at-risk

earlier, 2) to begin management programs before populations decline to critically low levels, and 3)

to pick the best sites for the establishment and/or restoration of highly productive, or source

populations. For mobile animals and birds, between-patch movements may contribute greatly to

local within-patch dynamics, so the effectiveness of local management programs at all sites must

be evaluated within the context of overall population changes on a regional or metapopulation

scale. Previous work on estimating various dynamics parameters for migratory bird and other

animal populations mostly has involved the separate estimation of breeding population sizes,

reproductive rates, and survival rates, but it is now believed that the movements of individuals

among the groups that make up metapopulations also are important factors affecting population

sizes and rates of change. Further, in species where two parents usually share the duties of

raising young, differences in the demographic parameters of the two sexes need to considered.

The unequal sex-ratio in the breeding population of the study species (Roseate Tern, Sterna

dougallii) has resulted in many females forming odd mating associations consisting of

female-female pairs, trios of one male and two females, or multi- female groups. The productivity of

such groups usually is much less than that of typical male- female pairs and the relative lack of

males, therefore, may be a significant factor limiting overall population productivity and recovery.

Keywords capturerecapture models, long-term monitoring and resea, long-term research, metapopulation

dynamics, restoration ecology, roseate tern, species-at-risk,

Principal Jeffrey A Spendelow, USGS Patuxent Wildlife Research Center:;

Investigators James D Nichols, USGS Patuxent Wildlife Research Center:; Ian C

Nisbet, I.C.T. Nisbet & Company:; Jeremy J Hatch, University of

Massachusetts:; Joanna Burger, Rutgers University:; Helen Hays, Great Gull Island Project American Museum of Natural

History:; David A Shealer, Loras College:; James M Zingo,

University of Massachusetts:; Jeff S Hatfield, USGS Patuxent Wildlife

Research Center:; William L Kendall, USGS Patuxent Wildlife Research

Center:; Patricia K Szczys, University of Massachusetts/Boston:;

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