Summary & Purpose

Wildfires and invasive species have caused widespread changes in western North America's shrub-steppe landscapes. The bottom-up consequences of degraded shrublands on predator ecology and demography remain poorly understood. We used a before-after paired design to study whether Golden Eagle (Aquila chrysaetos) diet and nestling survivorship changed following wildfires in southwestern Idaho, USA. We assessed burn extents from 1981 – 2013 and vegetation changes between 1979 (pre-burn) and 2014 (post-burn) within 3 km of Golden Eagle nesting centroids. We measured the frequency and biomass of individual prey, calculated diet diversity indexes, and monitored nestling survivorship at 15 territories in 1971 – 1981 and 2014 – 2015. On average, 0.70 of the area within 3 km of nesting centroids burned between 1981 – 2013, and the mean proportion of unburned shrubland decreased from 0.73 in 1979 to 0.22 in 2014. Diets in post-burn years were more diverse and had a lower proportion of some shrub-associated species, like Black-tailed Jackrabbits (Lepus californicus) and Mountain Cottontails (Sylvilagus nuttallii), and a higher proportion of American Coots (Fulica americana), Mallards (Anas platyrhynchos), Piute Ground Squirrels (Urocitellus mollis), and Rock Pigeons (Columba livia) compared to pre-burn years. A high proportion of waterfowl represented a novel change in Golden Eagle diets, which are typically dominated by mammalian prey. Nestling survivorship was positively associated with the proportion of Black-tailed Jackrabbits and negatively associated with the proportion of Rock Pigeons in eagle diets. Rock Pigeons are a vector for Trichomonas gallinae, a disease-causing protozoan lethal to young eagles. Nesting attempts were more likely to fail (all young die) in the post-burn period compared to the pre-burn period. Dietary shifts are a common mechanism for predators to cope with landscape change, but shifts away from preferred prey to disease vectors affect nestling survivorship and could lead to population-level effects on productivity.

Author Identifier

Julie A. Heath, ORCID: 0000-0002-9606-1689
Mike Kochert, ORCID: 0000-0002-4380-3298

Date of Publication or Submission

6-8-2021

DOI

https://doi.org/10.18122/bio_data.8.boisestate

Funding Citation

Funded by the USFWS Western Golden Eagle Team (F14AP00167 and F15AP00200), BLM (L14AC00342), the National Science Foundation (NSF) Idaho EPSCoR Program (award IIA-1301792), NSF Division of Biological Infrastructure (award 1263167), and the Raptor Research Center and Department of Biological Sciences at Boise State University.

Single Dataset or Series?

Series

Data Format

*.csv; *.png; *.txt

Data Attributes

See file: READ ME for goea diet data 20210601.txt

Time Period

1971-1981 and 2014-2015

Use Restrictions

Users are free to share, copy, distribute and use the dataset; to create or produce works from the dataset; to adapt, modify, transform and build upon the dataset as long as the user attributes any public use of the dataset, or works produced from the dataset, referencing the author(s) and DOI link. For any use or redistribution of the dataset, or works produced from it, the user must make clear to others the license of the dataset and keep intact any notices on the original dataset.

Disclaimer of Warranty

BOISE STATE UNIVERSITY MAKES NO REPRESENTATIONS ABOUT THE SUITABILITY OF THE INFORMATION CONTAINED IN OR PROVIDED AS PART OF THE SYSTEM FOR ANY PURPOSE. ALL SUCH INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. BOISE STATE UNIVERSITY HEREBY DISCLAIMS ALL WARRANTIES AND CONDITIONS WITH REGARD TO THIS INFORMATION, INCLUDING ALL WARRANTIES AND CONDITIONS OF MERCHANTABILITY, WHETHER EXPRESS, IMPLIED OR STATUTORY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT.

IN NO EVENT SHALL BOISE STATE UNIVERSITY BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF INFORMATION AVAILABLE FROM THE SYSTEM.

THE INFORMATION PROVIDED BY THE SYSTEM COULD INCLUDE TECHNICAL INACCURACIES OR TYPOGRAPHICAL ERRORS. CHANGES ARE PERIODICALLY ADDED TO THE INFORMATION HEREIN. COMPANY AND/OR ITS RESPECTIVE SUPPLIERS MAY MAKE IMPROVEMENTS AND/OR CHANGES IN THE PRODUCT(S) AND/OR THE PROGRAM(S) DESCRIBED HEREIN AT ANY TIME, WITH OR WITHOUT NOTICE TO YOU.

BOISE STATE UNIVERSITY DOES NOT MAKE ANY ASSURANCES WITH REGARD TO THE ACCURACY OF THE RESULTS OR OUTPUT THAT DERIVES FROM USE OF THE SYSTEM.

Comments

Dataset Contributors: Jordan Harrison, Steve Crane, A. Bammann, J. Doremus, Ben Dudek, Caitlin Davis, Mike Henderson, and Erin Arnold

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