Seasonal, Age, and Sex Differences in Weight, Fat Reserves, and Plasma Corticosterone in Western Sandpipers
Abstract Western Sandpipers (Calidris mauri) were followed throughout their annual cycle along the Pacific Coast of North America. Changes in body condition and corticosterone were tracked at two overwintering sites (Ensenada, Mexico, and San Diego, California), four migration stopover sites (Bodega...
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croxfordunivpr:10.1093/condor/105.1.13 2023-12-31T10:20:22+01:00 Seasonal, Age, and Sex Differences in Weight, Fat Reserves, and Plasma Corticosterone in Western Sandpipers O'Reilly, Kathleen M. Wingfield, John C. 2003 http://dx.doi.org/10.1093/condor/105.1.13 http://academic.oup.com/condor/article-pdf/105/1/13/29712199/condor0013.pdf en eng Oxford University Press (OUP) The Condor volume 105, issue 1, page 13-26 ISSN 0010-5422 1938-5129 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 2003 croxfordunivpr https://doi.org/10.1093/condor/105.1.13 2023-12-06T08:42:54Z Abstract Western Sandpipers (Calidris mauri) were followed throughout their annual cycle along the Pacific Coast of North America. Changes in body condition and corticosterone were tracked at two overwintering sites (Ensenada, Mexico, and San Diego, California), four migration stopover sites (Bodega Bay, California, Grays Harbor and False Bay, Washington, and Hartney Bay, Alaska), and a breeding site (Nome, Alaska). Adult males and females had elevated weight and fat scores during spring migration, breeding, and autumn migration relative to lean levels during winter. Although elevated mass and fat reserves may hinder escape from predators and are not necessary at wintering sites with benign conditions, the cost-benefit trade-offs with weight and agility shift during migration and breeding. Extra fat and muscle are necessary for fueling the long flight to and from the breeding grounds and serve as a hedge against unpredictable food and weather conditions on the breeding grounds. First-year birds weighed less and had lower fat reserves at smaller stopover sites than migrants at a large stopover site. Plasma levels of corticosterone revealed seasonal differences in the adrenocortical response to stress, although initial levels were fairly consistent across seasons. The highest stress response of the annual cycle in males was during autumn migration, in contrast to the lowest levels during early spring migration, breeding, and overwintering. Late-spring migrants and autumn premigrants had intermediate stress responses. An emerging pattern from this and other shorebird studies is that migrants with imminent flights of more than 1000 km have elevated corticosterone levels. Diferencias Estacionales de Edad y Sexo en Peso, Reservas de Grasa y Corticosterona Plasmática en Calidris mauri Resumen. Se siguieron individuos de Calidris mauri a través de su ciclo anual a lo largo de la costa Pacífica de Norteamérica. Se evaluaron los cambios en la condición corporal y la corticosterona en dos sitios de invernación (Ensenada, ... Article in Journal/Newspaper Nome Alaska Oxford University Press (via Crossref) The Condor 105 1 13 26 |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics O'Reilly, Kathleen M. Wingfield, John C. Seasonal, Age, and Sex Differences in Weight, Fat Reserves, and Plasma Corticosterone in Western Sandpipers |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Abstract Western Sandpipers (Calidris mauri) were followed throughout their annual cycle along the Pacific Coast of North America. Changes in body condition and corticosterone were tracked at two overwintering sites (Ensenada, Mexico, and San Diego, California), four migration stopover sites (Bodega Bay, California, Grays Harbor and False Bay, Washington, and Hartney Bay, Alaska), and a breeding site (Nome, Alaska). Adult males and females had elevated weight and fat scores during spring migration, breeding, and autumn migration relative to lean levels during winter. Although elevated mass and fat reserves may hinder escape from predators and are not necessary at wintering sites with benign conditions, the cost-benefit trade-offs with weight and agility shift during migration and breeding. Extra fat and muscle are necessary for fueling the long flight to and from the breeding grounds and serve as a hedge against unpredictable food and weather conditions on the breeding grounds. First-year birds weighed less and had lower fat reserves at smaller stopover sites than migrants at a large stopover site. Plasma levels of corticosterone revealed seasonal differences in the adrenocortical response to stress, although initial levels were fairly consistent across seasons. The highest stress response of the annual cycle in males was during autumn migration, in contrast to the lowest levels during early spring migration, breeding, and overwintering. Late-spring migrants and autumn premigrants had intermediate stress responses. An emerging pattern from this and other shorebird studies is that migrants with imminent flights of more than 1000 km have elevated corticosterone levels. Diferencias Estacionales de Edad y Sexo en Peso, Reservas de Grasa y Corticosterona Plasmática en Calidris mauri Resumen. Se siguieron individuos de Calidris mauri a través de su ciclo anual a lo largo de la costa Pacífica de Norteamérica. Se evaluaron los cambios en la condición corporal y la corticosterona en dos sitios de invernación (Ensenada, ... |
format |
Article in Journal/Newspaper |
author |
O'Reilly, Kathleen M. Wingfield, John C. |
author_facet |
O'Reilly, Kathleen M. Wingfield, John C. |
author_sort |
O'Reilly, Kathleen M. |
title |
Seasonal, Age, and Sex Differences in Weight, Fat Reserves, and Plasma Corticosterone in Western Sandpipers |
title_short |
Seasonal, Age, and Sex Differences in Weight, Fat Reserves, and Plasma Corticosterone in Western Sandpipers |
title_full |
Seasonal, Age, and Sex Differences in Weight, Fat Reserves, and Plasma Corticosterone in Western Sandpipers |
title_fullStr |
Seasonal, Age, and Sex Differences in Weight, Fat Reserves, and Plasma Corticosterone in Western Sandpipers |
title_full_unstemmed |
Seasonal, Age, and Sex Differences in Weight, Fat Reserves, and Plasma Corticosterone in Western Sandpipers |
title_sort |
seasonal, age, and sex differences in weight, fat reserves, and plasma corticosterone in western sandpipers |
publisher |
Oxford University Press (OUP) |
publishDate |
2003 |
url |
http://dx.doi.org/10.1093/condor/105.1.13 http://academic.oup.com/condor/article-pdf/105/1/13/29712199/condor0013.pdf |
genre |
Nome Alaska |
genre_facet |
Nome Alaska |
op_source |
The Condor volume 105, issue 1, page 13-26 ISSN 0010-5422 1938-5129 |
op_doi |
https://doi.org/10.1093/condor/105.1.13 |
container_title |
The Condor |
container_volume |
105 |
container_issue |
1 |
container_start_page |
13 |
op_container_end_page |
26 |
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1786830684912877568 |