Timing of spring migration of Norwegian Great Cormorants: long-term trends and effects of winter severity

Seabird Journal Pub Date : 2023-01-01 DOI:10.61350/sbj.35.5
Snæþór Aðalsteinsson, Aïda López, Thomas Bregnballe
{"title":"Timing of spring migration of Norwegian Great Cormorants: long-term trends and effects of winter severity","authors":"Snæþór Aðalsteinsson, Aïda López, Thomas Bregnballe","doi":"10.61350/sbj.35.5","DOIUrl":null,"url":null,"abstract":"Migratory birds are showing species-specific responses to climate change through changes in phenology, distribution and abundance. While many bird observatories collect standardised data on migratory passerines to provide invaluable information on changes in their abundances and migratory phenology, some bird observatories also undertake visual observations of passing migratory waterbirds and seabirds. In this study, we use two such long-term datasets of Great Cormorants (Phalacrocorax carbo) compiled during their spring migration. We explore the extent to which winter severity has affected their migration phenology and whether there have been long-term trends in migration timing. Observations were conducted at Lista Bird Observatory in southwest Norway (1992–2020) and at Skagen in north Jutland, Denmark (1974–98). At Skagen, there were no detectable long-term trends in Great Cormorant migratory timing. However, the median date (marking the passage of 50% of birds) was significantly advanced following warm winters. Changes in the date of passage of the first 10% of birds was close to doing so as well, but the late phase (the passage of 90% of birds) showed no relation to temperature. At Lista, winter temperatures in the southern part of the wintering area had no significant effect on the overall timing of the spring passage, but the first 10% of the Cormorants migrated significantly earlier in years with mild late March temperatures at Lista. The early phase of passage at Lista showed a significant long-term trend towards an advancement of migration, leading to an extended migration period. The findings of this study indicate that the timing of Great Cormorant spring migration does in some cases respond to late winter temperatures or show long-term trends, but that the responses and trends differ between sites and between the beginning, middle and late phases of the migration, with the early and middle phases generally showing stronger responses and trends than the late phase.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Seabird Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.61350/sbj.35.5","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

Abstract

Migratory birds are showing species-specific responses to climate change through changes in phenology, distribution and abundance. While many bird observatories collect standardised data on migratory passerines to provide invaluable information on changes in their abundances and migratory phenology, some bird observatories also undertake visual observations of passing migratory waterbirds and seabirds. In this study, we use two such long-term datasets of Great Cormorants (Phalacrocorax carbo) compiled during their spring migration. We explore the extent to which winter severity has affected their migration phenology and whether there have been long-term trends in migration timing. Observations were conducted at Lista Bird Observatory in southwest Norway (1992–2020) and at Skagen in north Jutland, Denmark (1974–98). At Skagen, there were no detectable long-term trends in Great Cormorant migratory timing. However, the median date (marking the passage of 50% of birds) was significantly advanced following warm winters. Changes in the date of passage of the first 10% of birds was close to doing so as well, but the late phase (the passage of 90% of birds) showed no relation to temperature. At Lista, winter temperatures in the southern part of the wintering area had no significant effect on the overall timing of the spring passage, but the first 10% of the Cormorants migrated significantly earlier in years with mild late March temperatures at Lista. The early phase of passage at Lista showed a significant long-term trend towards an advancement of migration, leading to an extended migration period. The findings of this study indicate that the timing of Great Cormorant spring migration does in some cases respond to late winter temperatures or show long-term trends, but that the responses and trends differ between sites and between the beginning, middle and late phases of the migration, with the early and middle phases generally showing stronger responses and trends than the late phase.
挪威大鸬鹚春季迁徙的时间:长期趋势和严冬的影响
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信