Data from: Quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis
1. Regular counts of migrating animals at stopover sites have been used as a measure of site importance at the global scale as well as for monitoring long-term population changes. However, migratory passage can last for several weeks and the turnover rate of individuals is often high, preventing the...
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fttriple:oai:gotriple.eu:50|dedup_wf_001::7c8a7d2ad549d3ddd0153daf56f0c2f8 2023-05-15T15:48:16+02:00 Data from: Quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis Catry, Teresa Lourenço, Pedro Miguel Granadeiro, Jose Pedro 2017-01-01 https://doi.org/10.5061/dryad.771p1 undefined unknown http://dx.doi.org/10.5061/dryad.771p1 https://dx.doi.org/10.5061/dryad.771p1 lic_creative-commons oai:services.nod.dans.knaw.nl:Products/dans:oai:easy.dans.knaw.nl:easy-dataset:98927 oai:easy.dans.knaw.nl:easy-dataset:98927 10.5061/dryad.771p1 10|eurocrisdris::fe4903425d9040f680d8610d9079ea14 10|re3data_____::84e123776089ce3c7a33db98d9cd15a8 10|openaire____::9e3be59865b2c1c335d32dae2fe7b254 10|re3data_____::94816e6421eeb072e7742ce6a9decc5f 10|openaire____::081b82f96300b6a6e3d282bad31cb6e2 re3data_____::r3d100000044 Life sciences medicine and health care Calidris alpina Migration stable isotopes shorebirds population size Stopover East Atlantic Flyway envir socio Dataset https://vocabularies.coar-repositories.org/resource_types/c_ddb1/ 2017 fttriple https://doi.org/10.5061/dryad.771p1 2023-01-22T16:51:33Z 1. Regular counts of migrating animals at stopover sites have been used as a measure of site importance at the global scale as well as for monitoring long-term population changes. However, migratory passage can last for several weeks and the turnover rate of individuals is often high, preventing the use of peak counts to estimate the total number of migrants. This estimate can be achieved, however, by combining count data with information on stopover length. 2. Here, we developed a new method to quantify the total number of migrant birds using stopover areas hosting overlapping populations of local (breeding, wintering or resident) and passage individuals of a given species. We illustrate the application of this method by estimating the number of spring migrant dunlins Calidris alpina stopping over at the Tagus estuary (Portugal). We used carbon and nitrogen isotopic signatures in toenails to identify migrants and to estimate their proportion in total counts. We then employed isotopic clock-models to determine time since arrival (TSA) of individuals from signatures in red blood cells and plasma and, using a simulation approach, we derived the relationship between TSA and stopover length. Finally, by dividing the number of migrants.day (obtained from counts) by the stopover length, we assessed the size of the migrant population. 3. We demonstrated that stopover length can be directly predicted from mean TSA values of birds sampled during migration, regardless of variations in (1) migratory rate, i.e., the phenology of arrivals throughout the migratory period and (2) the number of birds involved in the migratory event. Migrant dunlins stayed on average 7.5 days at the Tagus estuary during spring migration, which combined with count data resulted in an estimate of ca. 30000 passage dunlins using the study site. 4. Our novel approach is not strict in its assumptions, and therefore can be customized to the specificities of different taxa and study areas. Estimates of total number of migrants along migratory flyways ... Dataset Calidris alpina Unknown |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
unknown |
topic |
Life sciences medicine and health care Calidris alpina Migration stable isotopes shorebirds population size Stopover East Atlantic Flyway envir socio |
spellingShingle |
Life sciences medicine and health care Calidris alpina Migration stable isotopes shorebirds population size Stopover East Atlantic Flyway envir socio Catry, Teresa Lourenço, Pedro Miguel Granadeiro, Jose Pedro Data from: Quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis |
topic_facet |
Life sciences medicine and health care Calidris alpina Migration stable isotopes shorebirds population size Stopover East Atlantic Flyway envir socio |
description |
1. Regular counts of migrating animals at stopover sites have been used as a measure of site importance at the global scale as well as for monitoring long-term population changes. However, migratory passage can last for several weeks and the turnover rate of individuals is often high, preventing the use of peak counts to estimate the total number of migrants. This estimate can be achieved, however, by combining count data with information on stopover length. 2. Here, we developed a new method to quantify the total number of migrant birds using stopover areas hosting overlapping populations of local (breeding, wintering or resident) and passage individuals of a given species. We illustrate the application of this method by estimating the number of spring migrant dunlins Calidris alpina stopping over at the Tagus estuary (Portugal). We used carbon and nitrogen isotopic signatures in toenails to identify migrants and to estimate their proportion in total counts. We then employed isotopic clock-models to determine time since arrival (TSA) of individuals from signatures in red blood cells and plasma and, using a simulation approach, we derived the relationship between TSA and stopover length. Finally, by dividing the number of migrants.day (obtained from counts) by the stopover length, we assessed the size of the migrant population. 3. We demonstrated that stopover length can be directly predicted from mean TSA values of birds sampled during migration, regardless of variations in (1) migratory rate, i.e., the phenology of arrivals throughout the migratory period and (2) the number of birds involved in the migratory event. Migrant dunlins stayed on average 7.5 days at the Tagus estuary during spring migration, which combined with count data resulted in an estimate of ca. 30000 passage dunlins using the study site. 4. Our novel approach is not strict in its assumptions, and therefore can be customized to the specificities of different taxa and study areas. Estimates of total number of migrants along migratory flyways ... |
format |
Dataset |
author |
Catry, Teresa Lourenço, Pedro Miguel Granadeiro, Jose Pedro |
author_facet |
Catry, Teresa Lourenço, Pedro Miguel Granadeiro, Jose Pedro |
author_sort |
Catry, Teresa |
title |
Data from: Quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis |
title_short |
Data from: Quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis |
title_full |
Data from: Quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis |
title_fullStr |
Data from: Quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis |
title_full_unstemmed |
Data from: Quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis |
title_sort |
data from: quantifying population size of migrant birds at stopover sites: combining count data with stopover length estimated from stable isotope analysis |
publishDate |
2017 |
url |
https://doi.org/10.5061/dryad.771p1 |
genre |
Calidris alpina |
genre_facet |
Calidris alpina |
op_source |
oai:services.nod.dans.knaw.nl:Products/dans:oai:easy.dans.knaw.nl:easy-dataset:98927 oai:easy.dans.knaw.nl:easy-dataset:98927 10.5061/dryad.771p1 10|eurocrisdris::fe4903425d9040f680d8610d9079ea14 10|re3data_____::84e123776089ce3c7a33db98d9cd15a8 10|openaire____::9e3be59865b2c1c335d32dae2fe7b254 10|re3data_____::94816e6421eeb072e7742ce6a9decc5f 10|openaire____::081b82f96300b6a6e3d282bad31cb6e2 re3data_____::r3d100000044 |
op_relation |
http://dx.doi.org/10.5061/dryad.771p1 https://dx.doi.org/10.5061/dryad.771p1 |
op_rights |
lic_creative-commons |
op_doi |
https://doi.org/10.5061/dryad.771p1 |
_version_ |
1766383256298586112 |