Age bias in the bag of pink-footed geese Anser brachyrhynchus: influence of flocking behaviour on vulnerability
Abstract In pink-footed goose (Anser brachyrhynchus) wintering in Denmark, The Netherlands and Belgium, the proportion of juveniles in the hunting bag is consistently higher than that observed in the autumn population. Such juvenile bias in the bag is usually ascribed to young geese lacking experien...
Published in: | European Journal of Wildlife Research |
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Language: | English |
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2010
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Online Access: | http://hdl.handle.net/2262/48054 https://doi.org/10.1007/s10344-009-0349-1 |
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fttrinitycoll:oai:tara.tcd.ie:2262/48054 2023-05-15T13:29:56+02:00 Age bias in the bag of pink-footed geese Anser brachyrhynchus: influence of flocking behaviour on vulnerability 2010-12-19T02:52:41Z http://hdl.handle.net/2262/48054 https://doi.org/10.1007/s10344-009-0349-1 en eng Springer-Verlag Berlin/Heidelberg 1612-4642 (pISSN) 1439-0574 (eISSN) 16124642 (ISSN) 10344 (JournalID) s10344-009-0349-1 (publisherID) 349 (ArticleID) http://hdl.handle.net/2262/48054 European Journal of Wildlife Research 56 4 577 582 doi:10.1007/s10344-009-0349-1 Springer-Verlag, 2009 12 months Flocking Juvenile mortality Harvest Predation risk Predator swamping 2010 fttrinitycoll https://doi.org/10.1007/s10344-009-0349-1 2020-02-16T13:50:40Z Abstract In pink-footed goose (Anser brachyrhynchus) wintering in Denmark, The Netherlands and Belgium, the proportion of juveniles in the hunting bag is consistently higher than that observed in the autumn population. Such juvenile bias in the bag is usually ascribed to young geese lacking experience with hunting or disruption of juveniles from families. An alternative explanation may be that flocking behaviour of families make juveniles more vulnerable. Observations of morning flights of pink-footed geese to the feeding grounds from two of the major autumn-staging areas showed that geese were distributed in many small flocks (median flock size?=?9). This was not significantly different from the flock size distribution shot at by hunters (median?=?8), suggesting that hunters targeted goose flock size in proportion to the general probability of encounter. The rate at which hunters downed geese was independent of flock size. The ratio between juveniles and adults in flocks decreased with flock size and flocks of <60 individuals primarily comprised family groups. The likelihood of being shot at was 2.4 times higher for juveniles and 3.4 times higher for older birds in small flocks (<10 individuals) compared to larger flocks. The observations suggest that both juveniles as well as successful adult breeding birds were more vulnerable than non-breeding/failed breeding birds as a result of flocking behaviour. phone: +45-863-01940 (Madsen, Jesper) jm@dmu.dk (Madsen, Jesper) National Environmental Research Institute, Department of Arctic Environment, Aarhus University - Frederiksborgvej 399 - P.O. Box 358 - 4000 - Roskilde - DENMARK (Madsen, Jesper) DENMARK Registration: 2009-12-01 Received: 2009-07-10 Revised: 2009-11-22 Accepted: 2009-11-25 ePublished: 2009-12-19 Other/Unknown Material Anser brachyrhynchus Arctic National Environmental Research Institute Pink-footed Goose The University of Dublin, Trinity College: TARA (Trinity's Access to Research Archive) Arctic European Journal of Wildlife Research 56 4 577 582 |
institution |
Open Polar |
collection |
The University of Dublin, Trinity College: TARA (Trinity's Access to Research Archive) |
op_collection_id |
fttrinitycoll |
language |
English |
topic |
Flocking Juvenile mortality Harvest Predation risk Predator swamping |
spellingShingle |
Flocking Juvenile mortality Harvest Predation risk Predator swamping Age bias in the bag of pink-footed geese Anser brachyrhynchus: influence of flocking behaviour on vulnerability |
topic_facet |
Flocking Juvenile mortality Harvest Predation risk Predator swamping |
description |
Abstract In pink-footed goose (Anser brachyrhynchus) wintering in Denmark, The Netherlands and Belgium, the proportion of juveniles in the hunting bag is consistently higher than that observed in the autumn population. Such juvenile bias in the bag is usually ascribed to young geese lacking experience with hunting or disruption of juveniles from families. An alternative explanation may be that flocking behaviour of families make juveniles more vulnerable. Observations of morning flights of pink-footed geese to the feeding grounds from two of the major autumn-staging areas showed that geese were distributed in many small flocks (median flock size?=?9). This was not significantly different from the flock size distribution shot at by hunters (median?=?8), suggesting that hunters targeted goose flock size in proportion to the general probability of encounter. The rate at which hunters downed geese was independent of flock size. The ratio between juveniles and adults in flocks decreased with flock size and flocks of <60 individuals primarily comprised family groups. The likelihood of being shot at was 2.4 times higher for juveniles and 3.4 times higher for older birds in small flocks (<10 individuals) compared to larger flocks. The observations suggest that both juveniles as well as successful adult breeding birds were more vulnerable than non-breeding/failed breeding birds as a result of flocking behaviour. phone: +45-863-01940 (Madsen, Jesper) jm@dmu.dk (Madsen, Jesper) National Environmental Research Institute, Department of Arctic Environment, Aarhus University - Frederiksborgvej 399 - P.O. Box 358 - 4000 - Roskilde - DENMARK (Madsen, Jesper) DENMARK Registration: 2009-12-01 Received: 2009-07-10 Revised: 2009-11-22 Accepted: 2009-11-25 ePublished: 2009-12-19 |
title |
Age bias in the bag of pink-footed geese Anser brachyrhynchus: influence of flocking behaviour on vulnerability |
title_short |
Age bias in the bag of pink-footed geese Anser brachyrhynchus: influence of flocking behaviour on vulnerability |
title_full |
Age bias in the bag of pink-footed geese Anser brachyrhynchus: influence of flocking behaviour on vulnerability |
title_fullStr |
Age bias in the bag of pink-footed geese Anser brachyrhynchus: influence of flocking behaviour on vulnerability |
title_full_unstemmed |
Age bias in the bag of pink-footed geese Anser brachyrhynchus: influence of flocking behaviour on vulnerability |
title_sort |
age bias in the bag of pink-footed geese anser brachyrhynchus: influence of flocking behaviour on vulnerability |
publisher |
Springer-Verlag |
publishDate |
2010 |
url |
http://hdl.handle.net/2262/48054 https://doi.org/10.1007/s10344-009-0349-1 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Anser brachyrhynchus Arctic National Environmental Research Institute Pink-footed Goose |
genre_facet |
Anser brachyrhynchus Arctic National Environmental Research Institute Pink-footed Goose |
op_relation |
1612-4642 (pISSN) 1439-0574 (eISSN) 16124642 (ISSN) 10344 (JournalID) s10344-009-0349-1 (publisherID) 349 (ArticleID) http://hdl.handle.net/2262/48054 European Journal of Wildlife Research 56 4 577 582 doi:10.1007/s10344-009-0349-1 |
op_rights |
Springer-Verlag, 2009 12 months |
op_doi |
https://doi.org/10.1007/s10344-009-0349-1 |
container_title |
European Journal of Wildlife Research |
container_volume |
56 |
container_issue |
4 |
container_start_page |
577 |
op_container_end_page |
582 |
_version_ |
1766004351412731904 |