Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States
Golden eagles ( Aquila chrysaetos ) are of increasing conservation concern in western North America. Effective conservation measures for this wide-ranging, federally protected raptor species require monitoring frameworks that accommodate strong inference on the status of breeding populations across...
Published in: | Frontiers in Ecology and Evolution |
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Online Access: | http://dx.doi.org/10.3389/fevo.2021.665792 https://www.frontiersin.org/articles/10.3389/fevo.2021.665792/full |
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crfrontiers:10.3389/fevo.2021.665792 2024-02-11T10:09:29+01:00 Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States Wiens, J. David Bloom, Peter H. Madden, Melanie C. Kolar, Patrick S. Tracey, Jeff A. Fisher, Robert N. 2022 http://dx.doi.org/10.3389/fevo.2021.665792 https://www.frontiersin.org/articles/10.3389/fevo.2021.665792/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Ecology and Evolution volume 9 ISSN 2296-701X Ecology Ecology, Evolution, Behavior and Systematics journal-article 2022 crfrontiers https://doi.org/10.3389/fevo.2021.665792 2024-01-26T09:59:37Z Golden eagles ( Aquila chrysaetos ) are of increasing conservation concern in western North America. Effective conservation measures for this wide-ranging, federally protected raptor species require monitoring frameworks that accommodate strong inference on the status of breeding populations across vast landscapes. We used a broad-scale sampling design to identify relationships between landscape conditions, detection rates, and site occupancy by territorial pairs of golden eagles in coastal southern California, United States. In 2016 and 2017, we surveyed 175 territory-sized sample sites (13.9-km 2 randomly selected grid cells) up to four times each year and detected a pair of eagles at least once in 22 (12.6%) sites. The probability of detecting pairs of eagles varied substantially between years and declined with increasing amounts of forest cover at survey sites, which obscured observations of eagles during ground-based surveys. After accounting for variable detection, the mean estimate of expected site occupancy by eagle pairs was 0.156 (SE = 0.081). Site-level estimates of occupancy were greatest (>0.30) at sample sites with more rugged terrain conditions, <20% human development, and lower amounts of scrubland vegetation cover. The proportion of a sample site with open grassland or forest cover was not strongly correlated with occupancy. We estimated that approximately 16% of the 5,338-km 2 sampling frame was used by resident pairs of golden eagles, corresponding to a sparsely distributed population of about 60 pairs (95% CI = 19 – 151 pairs). Our study provided baseline data for future surveys of golden eagles along with a widely applicable monitoring framework for identifying spatial conservation priorities in urbanizing landscapes. Article in Journal/Newspaper Aquila chrysaetos golden eagle Frontiers (Publisher) Frontiers in Ecology and Evolution 9 |
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topic |
Ecology Ecology, Evolution, Behavior and Systematics |
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Ecology Ecology, Evolution, Behavior and Systematics Wiens, J. David Bloom, Peter H. Madden, Melanie C. Kolar, Patrick S. Tracey, Jeff A. Fisher, Robert N. Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States |
topic_facet |
Ecology Ecology, Evolution, Behavior and Systematics |
description |
Golden eagles ( Aquila chrysaetos ) are of increasing conservation concern in western North America. Effective conservation measures for this wide-ranging, federally protected raptor species require monitoring frameworks that accommodate strong inference on the status of breeding populations across vast landscapes. We used a broad-scale sampling design to identify relationships between landscape conditions, detection rates, and site occupancy by territorial pairs of golden eagles in coastal southern California, United States. In 2016 and 2017, we surveyed 175 territory-sized sample sites (13.9-km 2 randomly selected grid cells) up to four times each year and detected a pair of eagles at least once in 22 (12.6%) sites. The probability of detecting pairs of eagles varied substantially between years and declined with increasing amounts of forest cover at survey sites, which obscured observations of eagles during ground-based surveys. After accounting for variable detection, the mean estimate of expected site occupancy by eagle pairs was 0.156 (SE = 0.081). Site-level estimates of occupancy were greatest (>0.30) at sample sites with more rugged terrain conditions, <20% human development, and lower amounts of scrubland vegetation cover. The proportion of a sample site with open grassland or forest cover was not strongly correlated with occupancy. We estimated that approximately 16% of the 5,338-km 2 sampling frame was used by resident pairs of golden eagles, corresponding to a sparsely distributed population of about 60 pairs (95% CI = 19 – 151 pairs). Our study provided baseline data for future surveys of golden eagles along with a widely applicable monitoring framework for identifying spatial conservation priorities in urbanizing landscapes. |
format |
Article in Journal/Newspaper |
author |
Wiens, J. David Bloom, Peter H. Madden, Melanie C. Kolar, Patrick S. Tracey, Jeff A. Fisher, Robert N. |
author_facet |
Wiens, J. David Bloom, Peter H. Madden, Melanie C. Kolar, Patrick S. Tracey, Jeff A. Fisher, Robert N. |
author_sort |
Wiens, J. David |
title |
Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States |
title_short |
Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States |
title_full |
Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States |
title_fullStr |
Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States |
title_full_unstemmed |
Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States |
title_sort |
golden eagle occupancy surveys and monitoring strategy in coastal southern california, united states |
publisher |
Frontiers Media SA |
publishDate |
2022 |
url |
http://dx.doi.org/10.3389/fevo.2021.665792 https://www.frontiersin.org/articles/10.3389/fevo.2021.665792/full |
genre |
Aquila chrysaetos golden eagle |
genre_facet |
Aquila chrysaetos golden eagle |
op_source |
Frontiers in Ecology and Evolution volume 9 ISSN 2296-701X |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fevo.2021.665792 |
container_title |
Frontiers in Ecology and Evolution |
container_volume |
9 |
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1790609402940620800 |