Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields
Autor(a) principal: | |
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Data de Publicação: | 2002 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.5/1372 |
Resumo: | Rice fields are preferred feeding areas of mallard, Anas platyrhynchos, in Central Portugal. Rice consumption by mallards prior to crop harvest causes conflicts between farmers and waterfowl managers. We analysed the food habits of mallards collected in rice-fields and quantified the impact that mallards had on rice production. Oesophagi, including proventriculi (n=52), were obtained from hunter-shot mallards, from 15 August to late September 1993-1995, on a 600-ha farm included in the main feeding area of the lower Mondego population. Point counts were performed to estimate the numbers of mallards using the area. The diet included rice seeds (51.2% dry matter), weed seeds of rice fields (23.6% dry matter), and animal matter (25.1% dry matter). By means of the diet composition, we calculated that each mallard needed to ingest 93.4 g (dry matter) of food daily, including 47.8 g ogf rice, to meet its energy requirements. The estimated mallarg population using the area was 1600 ducks. They consumed approximately 0.2% of the 4,000 kg/ha minimum rice production. Therefore the decrease in rice production caused by mallargd was insignificant, which suggests that the existence of mallards on rice fields is compatible with rice production |
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Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fieldsmallardanas platyrhynchossummer dietrice fieldscrop damagePortugalRice fields are preferred feeding areas of mallard, Anas platyrhynchos, in Central Portugal. Rice consumption by mallards prior to crop harvest causes conflicts between farmers and waterfowl managers. We analysed the food habits of mallards collected in rice-fields and quantified the impact that mallards had on rice production. Oesophagi, including proventriculi (n=52), were obtained from hunter-shot mallards, from 15 August to late September 1993-1995, on a 600-ha farm included in the main feeding area of the lower Mondego population. Point counts were performed to estimate the numbers of mallards using the area. The diet included rice seeds (51.2% dry matter), weed seeds of rice fields (23.6% dry matter), and animal matter (25.1% dry matter). By means of the diet composition, we calculated that each mallard needed to ingest 93.4 g (dry matter) of food daily, including 47.8 g ogf rice, to meet its energy requirements. The estimated mallarg population using the area was 1600 ducks. They consumed approximately 0.2% of the 4,000 kg/ha minimum rice production. Therefore the decrease in rice production caused by mallargd was insignificant, which suggests that the existence of mallards on rice fields is compatible with rice productionRepositório da Universidade de LisboaFabião, AntónioRodrigues, D.Figueiredo, M.2009-10-23T15:08:25Z2002-032002-03-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.5/1372eng"Game and Wildlife Science". ISSN 1622-7662. 19: 1 (2002) 55-621622-7662info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-03-06T14:32:38Zoai:www.repository.utl.pt:10400.5/1372Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T16:49:31.487633Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields |
title |
Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields |
spellingShingle |
Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields Fabião, António mallard anas platyrhynchos summer diet rice fields crop damage Portugal |
title_short |
Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields |
title_full |
Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields |
title_fullStr |
Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields |
title_full_unstemmed |
Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields |
title_sort |
Mallard (Anas platyrhynchos) summer diet in Central Portugal rice fields |
author |
Fabião, António |
author_facet |
Fabião, António Rodrigues, D. Figueiredo, M. |
author_role |
author |
author2 |
Rodrigues, D. Figueiredo, M. |
author2_role |
author author |
dc.contributor.none.fl_str_mv |
Repositório da Universidade de Lisboa |
dc.contributor.author.fl_str_mv |
Fabião, António Rodrigues, D. Figueiredo, M. |
dc.subject.por.fl_str_mv |
mallard anas platyrhynchos summer diet rice fields crop damage Portugal |
topic |
mallard anas platyrhynchos summer diet rice fields crop damage Portugal |
description |
Rice fields are preferred feeding areas of mallard, Anas platyrhynchos, in Central Portugal. Rice consumption by mallards prior to crop harvest causes conflicts between farmers and waterfowl managers. We analysed the food habits of mallards collected in rice-fields and quantified the impact that mallards had on rice production. Oesophagi, including proventriculi (n=52), were obtained from hunter-shot mallards, from 15 August to late September 1993-1995, on a 600-ha farm included in the main feeding area of the lower Mondego population. Point counts were performed to estimate the numbers of mallards using the area. The diet included rice seeds (51.2% dry matter), weed seeds of rice fields (23.6% dry matter), and animal matter (25.1% dry matter). By means of the diet composition, we calculated that each mallard needed to ingest 93.4 g (dry matter) of food daily, including 47.8 g ogf rice, to meet its energy requirements. The estimated mallarg population using the area was 1600 ducks. They consumed approximately 0.2% of the 4,000 kg/ha minimum rice production. Therefore the decrease in rice production caused by mallargd was insignificant, which suggests that the existence of mallards on rice fields is compatible with rice production |
publishDate |
2002 |
dc.date.none.fl_str_mv |
2002-03 2002-03-01T00:00:00Z 2009-10-23T15:08:25Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.5/1372 |
url |
http://hdl.handle.net/10400.5/1372 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
"Game and Wildlife Science". ISSN 1622-7662. 19: 1 (2002) 55-62 1622-7662 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799130968722767872 |