Cornell University
Library
Cornell UniversityLibrary

eCommons

Help
Log In(current)
  1. Home
  2. Cornell University Graduate School
  3. Cornell Theses and Dissertations
  4. A WORLD OF DECISIONS: HOW CHOICES THROUGHOUT THE ANNUAL CYCLE AFFECT SURVIVAL, CONDITION, AND PERFORMANCE OF A MIGRATORY SHOREBIRD

A WORLD OF DECISIONS: HOW CHOICES THROUGHOUT THE ANNUAL CYCLE AFFECT SURVIVAL, CONDITION, AND PERFORMANCE OF A MIGRATORY SHOREBIRD

File(s)
Swift_cornellgrad_0058F_11043.pdf (11.87 MB)
Permanent Link(s)
https://doi.org/10.7298/X4GX48S2
https://hdl.handle.net/1813/59742
Collections
Cornell Theses and Dissertations
Author
Swift, Rose Jennetta
Abstract

Migratory birds face a variety of threats and constraints throughout the annual cycle, and events that occur in one season can impact individuals not only within that period, but in subsequent seasons as well. I investigated the consequences of decisions about habitat use and species interactions across the full annual cycle on the survival, condition, and performance of Hudsonian Godwits (Limosa haemastica) in Beluga River, Alaska and Chiloé Island, Chile. On the breeding grounds, I examined how the benefits of a protective nesting association between godwits and the loud and aggressive Mew Gulls (Larus canus) varied across time and space. Hudsonian Godwits actively chose to nest within gull colonies, but the advantages were context-dependent. Although godwits experienced higher nest survival within colonies – presumably because gulls dissuaded nest predators from using the area – godwit chicks were more likely to be depredated within colonies. Godwits nesting within colonies were larger (females only) and less attentive (males attended the nest less and gave fewer alarm calls). Nest survival was best explained by individual condition improving with female size within colonies and male size outside of colonies. Turning to the non-breeding grounds in southern Chile, I assessed the degree to which patch quality, as indicated by density and condition of godwits, was affected by environmental attributes and disturbance from predators and/or human activities. Patch quality was primarily influenced by availability of foraging habitat, foraging success rates, and the responses of godwits to disturbance (i.e., vigilance and agitation). Lastly, I examined cross-seasonal interactions on individual survival and performance. Godwits had high survival throughout the annual cycle, with the lowest survival estimates during the breeding season and southbound migration. I also found evidence of carry-over, or reversible state, effects on future reproductive performance, with individuals in better condition or using higher quality patches on non-breeding grounds achieving higher reproductive success the following spring. Understanding the interactions among stages of the annual cycle, the relative influence of non-breeding and breeding season factors, and the consequences of individual decisions on survival, condition, and performance will help inform conservation for this rapidly declining species.

Date Issued
2018-08-30
Keywords
Behavioral sciences
•
annual cycle
•
Hudsonian Godwit
•
interspecific interactions
•
Limosa haemastica
•
reversible state effects
•
shorebird
•
Ecology
•
Wildlife conservation
Committee Chair
Rodewald, Amanda Dumin
Committee Member
Senner, Nathan Robert
Fitzpatrick, John Weaver
Webster, Michael Stilson, Jr
Degree Discipline
Natural Resources
Degree Name
Ph. D., Natural Resources
Degree Level
Doctor of Philosophy
Type
dissertation or thesis

Site Statistics | Help

About eCommons | Policies | Terms of use | Contact Us

copyright © 2002-2026 Cornell University Library | Privacy | Web Accessibility Assistance