Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest
The three box-nesting passerine bird species pied flycatcher, great tit and common redstart breed at their distributional limit in Troms, Northern Norway. Access to food and favourable weather conditions is expected to be of importance for the birds´ breeding population dynamics. In the same area, g...
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Format: | Master Thesis |
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UiT Norges arktiske universitet
2017
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Online Access: | https://hdl.handle.net/10037/11135 |
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ftunivtroemsoe:oai:munin.uit.no:10037/11135 2023-05-15T17:43:36+02:00 Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest Bjørkås, Ragnhild 2017-05-15 https://hdl.handle.net/10037/11135 eng eng UiT Norges arktiske universitet UiT The Arctic University of Norway https://hdl.handle.net/10037/11135 openAccess Copyright 2017 The Author(s) VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 Ficedula hypoleuca Parus major Phoenicurus phoenicurus Operophtera brumata Epirrita autumnata Agriopis aurantiaria Moth larvae Temperature Breeding population dynamics Numerical response VDP::Mathematics and natural science: 400::Zoology and botany: 480 BIO-3950 Master thesis Mastergradsoppgave 2017 ftunivtroemsoe 2021-06-25T17:55:17Z The three box-nesting passerine bird species pied flycatcher, great tit and common redstart breed at their distributional limit in Troms, Northern Norway. Access to food and favourable weather conditions is expected to be of importance for the birds´ breeding population dynamics. In the same area, geometrid moth larvae experience cyclic population outbreaks at approx. 10 year intervals, constituting a superabundant and potentially important source of food for insectivorous birds during the breeding season. To assess if the birds´ breeding population dynamics could be explained by moth larval densities and summer temperatures, we conducted yearly inspections of nest box occupancy and moth larval counts during a period of 13 years at 12 study sites, and obtained temperature measurements from nearby weather stations. Results from GLMM models with a logit link function suggested a moderate positive numerical response of the bird community to high moth larval densities. The response was species specific, with the great tit showing the most consistent response – indicating that this species is probably more dependent on moth larvae during breeding season than the other two bird species. The bird community also showed a positive numerical response the year after high summer temperatures, likely because it caused higher breeding success and subsequent higher return rates of breeding birds. It was concluded that the focal bird community was positively affected by high moth larval densities and summer temperatures, but that other factors were probably also limiting on breeding population densities due to the moderate response. Master Thesis Northern Norway Subarctic Troms University of Tromsø: Munin Open Research Archive Norway Parus ENVELOPE(3.950,3.950,-71.983,-71.983) |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 Ficedula hypoleuca Parus major Phoenicurus phoenicurus Operophtera brumata Epirrita autumnata Agriopis aurantiaria Moth larvae Temperature Breeding population dynamics Numerical response VDP::Mathematics and natural science: 400::Zoology and botany: 480 BIO-3950 |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 Ficedula hypoleuca Parus major Phoenicurus phoenicurus Operophtera brumata Epirrita autumnata Agriopis aurantiaria Moth larvae Temperature Breeding population dynamics Numerical response VDP::Mathematics and natural science: 400::Zoology and botany: 480 BIO-3950 Bjørkås, Ragnhild Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 Ficedula hypoleuca Parus major Phoenicurus phoenicurus Operophtera brumata Epirrita autumnata Agriopis aurantiaria Moth larvae Temperature Breeding population dynamics Numerical response VDP::Mathematics and natural science: 400::Zoology and botany: 480 BIO-3950 |
description |
The three box-nesting passerine bird species pied flycatcher, great tit and common redstart breed at their distributional limit in Troms, Northern Norway. Access to food and favourable weather conditions is expected to be of importance for the birds´ breeding population dynamics. In the same area, geometrid moth larvae experience cyclic population outbreaks at approx. 10 year intervals, constituting a superabundant and potentially important source of food for insectivorous birds during the breeding season. To assess if the birds´ breeding population dynamics could be explained by moth larval densities and summer temperatures, we conducted yearly inspections of nest box occupancy and moth larval counts during a period of 13 years at 12 study sites, and obtained temperature measurements from nearby weather stations. Results from GLMM models with a logit link function suggested a moderate positive numerical response of the bird community to high moth larval densities. The response was species specific, with the great tit showing the most consistent response – indicating that this species is probably more dependent on moth larvae during breeding season than the other two bird species. The bird community also showed a positive numerical response the year after high summer temperatures, likely because it caused higher breeding success and subsequent higher return rates of breeding birds. It was concluded that the focal bird community was positively affected by high moth larval densities and summer temperatures, but that other factors were probably also limiting on breeding population densities due to the moderate response. |
format |
Master Thesis |
author |
Bjørkås, Ragnhild |
author_facet |
Bjørkås, Ragnhild |
author_sort |
Bjørkås, Ragnhild |
title |
Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest |
title_short |
Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest |
title_full |
Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest |
title_fullStr |
Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest |
title_full_unstemmed |
Spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest |
title_sort |
spatio-temporal dynamics in breeding occurrence of passerine birds in subarctic birch forest |
publisher |
UiT Norges arktiske universitet |
publishDate |
2017 |
url |
https://hdl.handle.net/10037/11135 |
long_lat |
ENVELOPE(3.950,3.950,-71.983,-71.983) |
geographic |
Norway Parus |
geographic_facet |
Norway Parus |
genre |
Northern Norway Subarctic Troms |
genre_facet |
Northern Norway Subarctic Troms |
op_relation |
https://hdl.handle.net/10037/11135 |
op_rights |
openAccess Copyright 2017 The Author(s) |
_version_ |
1766145711724822528 |