Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots
The long-distance migrant red knot (Calidris canutus ssp. rufa – Scolopacidae) alternates between the northern and southern ends of the New World, one of the longest yearly migrations of any bird and paradoxically overflying apparently suitable habitat at lower latitudes. This subspecies is sharply...
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Ecological Society of Australia
2012
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ftcsic:oai:digital.csic.es:10261/51870 2024-02-11T10:02:41+01:00 Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots Escudero, Graciela Navedo, Juan G. Piersma, Theunis de Goeij, Petra Edelaar, Pim 2012 http://hdl.handle.net/10261/51870 https://doi.org/10.1111/j.1442-9993.2011.02283.x en eng Ecological Society of Australia http://dx.doi.org/10.1111/j.1442-9993.2011.02283.x Austral Ecology (2012) 37, 355–364 http://hdl.handle.net/10261/51870 doi:10.1111/j.1442-9993.2011.02283.x open Calidris canutus rufa digenean parasite foraging ecology long-distance migration population decline artículo http://purl.org/coar/resource_type/c_6501 2012 ftcsic https://doi.org/10.1111/j.1442-9993.2011.02283.x 2024-01-16T09:38:46Z The long-distance migrant red knot (Calidris canutus ssp. rufa – Scolopacidae) alternates between the northern and southern ends of the New World, one of the longest yearly migrations of any bird and paradoxically overflying apparently suitable habitat at lower latitudes. This subspecies is sharply declining, with a major mortality event following 2000, attributed to commercial overharvesting of food resources at its Delaware Bay (USA) stop-over site. A full understanding of this peculiar migrant requires an assessment of the foraging conditions at its southern hemisphere wintering sites. Here, for a major wintering site in Argentinean Tierra del Fuego (Río Grande), we describe and compare food abundance, diet and intake rates during January–February in 1995, 2000 and 2008. The two main prey types were the burrowing clam Darina solenoides and three species of epibenthic mussels Mytilidae. In the year 2000, food availability and intake rate were higher than those recorded at other sites used by knots anywhere else in the world, contributing to the explanation of why red knots carry out this impressive migration. Intake rate in 2008 on the two main prey types was dramatically reduced as a result of birds eating smaller prey and strongly increased human disturbance; the same year we also found a high prevalence of a digenean parasite in Darina. We suggest that during the strongly enhanced winter mortality in 2000, knots did not yet face ecological problems in their southernmost wintering area, consistent with the previous evidence that problems at northern stop-overs negatively affected their numbers. However, in 2008 the ecological conditions at Río Grande were such that they would have facilitated a further decline, emphasizing the importance of a hemispheric approach to research and management Peer reviewed Article in Journal/Newspaper Calidris canutus Red Knot Tierra del Fuego Digital.CSIC (Spanish National Research Council) Austral Ecology 37 3 355 364 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
Calidris canutus rufa digenean parasite foraging ecology long-distance migration population decline |
spellingShingle |
Calidris canutus rufa digenean parasite foraging ecology long-distance migration population decline Escudero, Graciela Navedo, Juan G. Piersma, Theunis de Goeij, Petra Edelaar, Pim Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots |
topic_facet |
Calidris canutus rufa digenean parasite foraging ecology long-distance migration population decline |
description |
The long-distance migrant red knot (Calidris canutus ssp. rufa – Scolopacidae) alternates between the northern and southern ends of the New World, one of the longest yearly migrations of any bird and paradoxically overflying apparently suitable habitat at lower latitudes. This subspecies is sharply declining, with a major mortality event following 2000, attributed to commercial overharvesting of food resources at its Delaware Bay (USA) stop-over site. A full understanding of this peculiar migrant requires an assessment of the foraging conditions at its southern hemisphere wintering sites. Here, for a major wintering site in Argentinean Tierra del Fuego (Río Grande), we describe and compare food abundance, diet and intake rates during January–February in 1995, 2000 and 2008. The two main prey types were the burrowing clam Darina solenoides and three species of epibenthic mussels Mytilidae. In the year 2000, food availability and intake rate were higher than those recorded at other sites used by knots anywhere else in the world, contributing to the explanation of why red knots carry out this impressive migration. Intake rate in 2008 on the two main prey types was dramatically reduced as a result of birds eating smaller prey and strongly increased human disturbance; the same year we also found a high prevalence of a digenean parasite in Darina. We suggest that during the strongly enhanced winter mortality in 2000, knots did not yet face ecological problems in their southernmost wintering area, consistent with the previous evidence that problems at northern stop-overs negatively affected their numbers. However, in 2008 the ecological conditions at Río Grande were such that they would have facilitated a further decline, emphasizing the importance of a hemispheric approach to research and management Peer reviewed |
format |
Article in Journal/Newspaper |
author |
Escudero, Graciela Navedo, Juan G. Piersma, Theunis de Goeij, Petra Edelaar, Pim |
author_facet |
Escudero, Graciela Navedo, Juan G. Piersma, Theunis de Goeij, Petra Edelaar, Pim |
author_sort |
Escudero, Graciela |
title |
Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots |
title_short |
Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots |
title_full |
Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots |
title_fullStr |
Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots |
title_full_unstemmed |
Foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots |
title_sort |
foraging conditions ‘at the end of the world’ in the context of long-distance migration and population declines in red knots |
publisher |
Ecological Society of Australia |
publishDate |
2012 |
url |
http://hdl.handle.net/10261/51870 https://doi.org/10.1111/j.1442-9993.2011.02283.x |
genre |
Calidris canutus Red Knot Tierra del Fuego |
genre_facet |
Calidris canutus Red Knot Tierra del Fuego |
op_relation |
http://dx.doi.org/10.1111/j.1442-9993.2011.02283.x Austral Ecology (2012) 37, 355–364 http://hdl.handle.net/10261/51870 doi:10.1111/j.1442-9993.2011.02283.x |
op_rights |
open |
op_doi |
https://doi.org/10.1111/j.1442-9993.2011.02283.x |
container_title |
Austral Ecology |
container_volume |
37 |
container_issue |
3 |
container_start_page |
355 |
op_container_end_page |
364 |
_version_ |
1790598719889997824 |