Patterns in Age Structure of Golden Eagles Wintering in Eastern North America

Release Date:

Wildlife behavior varies seasonally, particularly for long-distance migrants, and that variation can have substantial demographic consequences. 

To figure out whether golden eagles of similar ages winter together, researchers analyzed 370,307 images collected by baited motion-sensitive trail cameras throughout eastern North America. At nine out of 200 sites with sufficient data for analysis, they documented 145 eagle visits in 2013 and 146 in 2014. As anticipated, they found variation between years in the proportion of first-winter golden eagles, but contrary to expectations, there was no age-related spatial structure in wintering populations. The lack of spatial segregation by age could mean that these eagles segregate by sex in wintering areas, or alternatively, that food availability or habitat may have been sufficient to reduce competition and explain the lack of age structure. This study shows how using trail cameras to study birds can result in important ecological insight.


Kenney, M.L., Belthoff, J.R., Carling, M., Miller, T.A., Katzner, T.E., 2020, Spatial and temporal patterns in age structure of Golden Eagles (Aquila chrysaetos) wintering in eastern North America: Journal of Field Ornithology,

Related Content

Filter Total Items: 1
Date published: November 6, 2017
Status: Active

Conservation Ecology and Monitoring of Raptors

Raptors, or birds of prey, are often used to indicate the state of an ecosystem, and monitoring their populations can help us to understand ecosystem processes. Raptors are particularly good animals for monitoring because they are big and therefore charismatic and easy to observe. Whether we’re monitoring nesting biology and reproductive output, counting individuals on roads, or setting up...

Contacts: Todd E Katzner