Skip to main content
WCS
Menu
Library
Library Catalog
eJournals & eBooks
WCS Research
Archives
Research Use
Finding Aids
Digital Collections
WCS History
WCS Research
Research Publications
Science Data
Services for WCS Researchers
Archives Shop
Bronx Zoo
Department of Tropical Research
Browse By Product
About Us
FAQs
Intern or Volunteer
Staff
Donate
Search WCS.org
Search
search
Popular Search Terms
WCS History
Library and Archives
Library and Archives Menu
Library
Archives
WCS Research
Archives Shop
About Us
Donate
en
fr
Title
Density-dependent winter survival of immatures in an irruptive raptor with pulsed breeding
Author(s)
McCabe, Rebecca A.;Therrien, Jean-François;Wiebe, Karen;Gauthier, Gilles;Brinker, David;Weidensaul, Scott;Reid, Donald;Doyle, Frank I.;Jacobsen, Karl-Otto;Aarvak, Tomas;Øien, Ingar Jostein;Solheim, Roar;Fitzgerald, Guy;Smith, Norman;Bates, Kirk;Fuller, Mark;Miller, Erica;Elliott, Kyle H.
Published
2022
Publisher
Oecologia
Published Version DOI
https://doi.org/10.1007/s00442-021-05057-9
Abstract
Highly mobile predators can show strong numerical responses to pulsed resources, sometimes resulting in irruptions where large numbers of young invade landscapes at a continental scale. High production of young in irruption years may have a strong influence on the population dynamics unless immature survival is reduced compared to non-irruption years. This could occur if subordinate individuals (mainly immatures) are forced into suboptimal habitats due to density-dependent effects in irruption years. To test whether irruptive individuals had lower survival than non-irruptive ones, we combined necropsy results (N = 365) with telemetry (N = 185) from more than 20 years to record timing and causes of mortality in snowy owls (Bubo scandiacus), which irrupt into eastern North America during winter following high breeding output caused by lemming peaks in the Arctic. Mortality was more than four times higher in irruption years than non-irruption years, but only for immatures, and occurred disproportionately in early winter for immatures, but not adults. Mortality was also higher in eastern North America, where owl abundance fluctuates considerably between years, compared to core winter regions of the Arctic and Prairies where populations are more stable. Most mortality was not due to starvation, but rather associated with human activity, especially vehicle collisions. We conclude that immature snowy owls that irrupt into eastern North America are limited by density-dependent factors, such as increased competition forcing individuals to occupy risky human-altered habitats. For highly mobile, irruptive animals, resource pulses may have a limited impact on population dynamics due to low subsequent survival of breeding output during the nonbreeding season.
Keywords
Biologging; Bubo scandiacus; Irruptions; Mortality; Necropsy
Access Full Text
A full-text copy of this article may be available. Please email the
WCS Library
to request.
Back
PUB27143