Revista Catalana d'Ornitologia Time-of-day bias in diurnal raptor abundance and richness estimated by road surveys
Road surveys are the most commonly used method for estimating the abundances of raptors, although biases may occur in relation to the time-of-day that surveys are conducted. However, very few studies have addressed the impact of time-of-day bias on the accuracy of survey results. In the present work...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.1088.9091 2023-05-15T15:55:34+02:00 Revista Catalana d'Ornitologia Time-of-day bias in diurnal raptor abundance and richness estimated by road surveys Pablo Vergara The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1088.9091 http://www.ornitologia.org/ca/queoferim/divulgacio/publicacions/rco/26_22_30.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1088.9091 http://www.ornitologia.org/ca/queoferim/divulgacio/publicacions/rco/26_22_30.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.ornitologia.org/ca/queoferim/divulgacio/publicacions/rco/26_22_30.pdf text ftciteseerx 2020-05-24T00:19:16Z Road surveys are the most commonly used method for estimating the abundances of raptors, although biases may occur in relation to the time-of-day that surveys are conducted. However, very few studies have addressed the impact of time-of-day bias on the accuracy of survey results. In the present work, several raptor species were surveyed over the course of a year at different times of day. In six of the 11 studied species, the time of day (hours after sunrise) affected the number of detected individuals and the estimation of species richness. Even slight differences in the time-of-day (e.g. two hours) had a significant impact on results. Furthermore, when detected the time-of-day variation was specific for each species: Hen Harrier Circus cyaneus, Montagu's Harrier C. pygargus, Common Buzzard Buteo buteo and Common Kestrel Falco tinnunculus were detected more often around sunrise, whereas Griffon Vulture Gyps fulvus and Short-toed Eagle Circaetus gallicus were most commonly detected later in the morning (at least two hours after sunrise). No interactions between the time-of-day and season (breeding vs. non-breeding) were found for the studied raptor species. The present study highlights the need to control for time-of-day bias when applying road survey methodology to raptor populations. Text Circus cyaneus Unknown |
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English |
description |
Road surveys are the most commonly used method for estimating the abundances of raptors, although biases may occur in relation to the time-of-day that surveys are conducted. However, very few studies have addressed the impact of time-of-day bias on the accuracy of survey results. In the present work, several raptor species were surveyed over the course of a year at different times of day. In six of the 11 studied species, the time of day (hours after sunrise) affected the number of detected individuals and the estimation of species richness. Even slight differences in the time-of-day (e.g. two hours) had a significant impact on results. Furthermore, when detected the time-of-day variation was specific for each species: Hen Harrier Circus cyaneus, Montagu's Harrier C. pygargus, Common Buzzard Buteo buteo and Common Kestrel Falco tinnunculus were detected more often around sunrise, whereas Griffon Vulture Gyps fulvus and Short-toed Eagle Circaetus gallicus were most commonly detected later in the morning (at least two hours after sunrise). No interactions between the time-of-day and season (breeding vs. non-breeding) were found for the studied raptor species. The present study highlights the need to control for time-of-day bias when applying road survey methodology to raptor populations. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Pablo Vergara |
spellingShingle |
Pablo Vergara Revista Catalana d'Ornitologia Time-of-day bias in diurnal raptor abundance and richness estimated by road surveys |
author_facet |
Pablo Vergara |
author_sort |
Pablo Vergara |
title |
Revista Catalana d'Ornitologia Time-of-day bias in diurnal raptor abundance and richness estimated by road surveys |
title_short |
Revista Catalana d'Ornitologia Time-of-day bias in diurnal raptor abundance and richness estimated by road surveys |
title_full |
Revista Catalana d'Ornitologia Time-of-day bias in diurnal raptor abundance and richness estimated by road surveys |
title_fullStr |
Revista Catalana d'Ornitologia Time-of-day bias in diurnal raptor abundance and richness estimated by road surveys |
title_full_unstemmed |
Revista Catalana d'Ornitologia Time-of-day bias in diurnal raptor abundance and richness estimated by road surveys |
title_sort |
revista catalana d'ornitologia time-of-day bias in diurnal raptor abundance and richness estimated by road surveys |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1088.9091 http://www.ornitologia.org/ca/queoferim/divulgacio/publicacions/rco/26_22_30.pdf |
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Circus cyaneus |
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Circus cyaneus |
op_source |
http://www.ornitologia.org/ca/queoferim/divulgacio/publicacions/rco/26_22_30.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1088.9091 http://www.ornitologia.org/ca/queoferim/divulgacio/publicacions/rco/26_22_30.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766391058852216832 |