Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore
How herbivore behaviour is influenced by changes in resource levels is central for understanding trophic interactions. We examined whether foraging tradeoffs change with food levels by comparing habitat selection and space use within and between two neighbouring, predator‐free Svalbard reindeer popu...
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crwiley:10.1111/j.1600-0706.2009.17098.x 2024-09-15T18:38:27+00:00 Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore Bremset Hansen, Brage Herfindal, Ivar Aanes, Ronny Sæther, Bernt‐Erik Henriksen, Snorre 2009 http://dx.doi.org/10.1111/j.1600-0706.2009.17098.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0706.2009.17098.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0706.2009.17098.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Oikos volume 118, issue 6, page 859-872 ISSN 0030-1299 1600-0706 journal-article 2009 crwiley https://doi.org/10.1111/j.1600-0706.2009.17098.x 2024-08-01T04:23:53Z How herbivore behaviour is influenced by changes in resource levels is central for understanding trophic interactions. We examined whether foraging tradeoffs change with food levels by comparing habitat selection and space use within and between two neighbouring, predator‐free Svalbard reindeer populations. The populations faced different food levels due to contrasting grazing history. Summer resource selection in radiocollared females was assessed by a multi‐dimensional niche approach based on habitat variables obtained from a satellite image (e.g. the normalised difference vegetation index, NDVI) and a digital terrain model. The population at the overgrazed Brøggerhalvøya faced overall lower plant cover, biomass and primary productivity (i.e. lower NDVI) than the population at Sarsøyra. At Brøggerhalvøya, most reindeer selected for productive habitat when choosing home range and patches within the home range. In contrast, habitat selection at Sarsøyra was more affected by abiotic conditions such as moisture, which may influence plant quality. Here, reindeer used patches with even less biomass than the average reindeer at the poorer Brøggerhalvøya. Such a difference in habitat preference with different habitat availability (a functional response in habitat selection) probably reflected increased selection for high‐quality forage at the expense of high forage quantity at Sarsøyra. Accordingly, a negative relationship between habitat productivity and home range size was only present across individuals within Brøggerhalvøya, where forage quantity was the important foraging niche component. Individuals having poor (and large) home ranges apparently could not compensate for this by higher patch selectivity compared to individuals with richer home ranges. The results indicate changes in foraging tradeoffs at contrasting resource levels and that strong interactions occur between habitat selection, space use and the foraging niche structure in the absence of predation. Article in Journal/Newspaper Svalbard svalbard reindeer Wiley Online Library Oikos 118 6 859 872 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
How herbivore behaviour is influenced by changes in resource levels is central for understanding trophic interactions. We examined whether foraging tradeoffs change with food levels by comparing habitat selection and space use within and between two neighbouring, predator‐free Svalbard reindeer populations. The populations faced different food levels due to contrasting grazing history. Summer resource selection in radiocollared females was assessed by a multi‐dimensional niche approach based on habitat variables obtained from a satellite image (e.g. the normalised difference vegetation index, NDVI) and a digital terrain model. The population at the overgrazed Brøggerhalvøya faced overall lower plant cover, biomass and primary productivity (i.e. lower NDVI) than the population at Sarsøyra. At Brøggerhalvøya, most reindeer selected for productive habitat when choosing home range and patches within the home range. In contrast, habitat selection at Sarsøyra was more affected by abiotic conditions such as moisture, which may influence plant quality. Here, reindeer used patches with even less biomass than the average reindeer at the poorer Brøggerhalvøya. Such a difference in habitat preference with different habitat availability (a functional response in habitat selection) probably reflected increased selection for high‐quality forage at the expense of high forage quantity at Sarsøyra. Accordingly, a negative relationship between habitat productivity and home range size was only present across individuals within Brøggerhalvøya, where forage quantity was the important foraging niche component. Individuals having poor (and large) home ranges apparently could not compensate for this by higher patch selectivity compared to individuals with richer home ranges. The results indicate changes in foraging tradeoffs at contrasting resource levels and that strong interactions occur between habitat selection, space use and the foraging niche structure in the absence of predation. |
format |
Article in Journal/Newspaper |
author |
Bremset Hansen, Brage Herfindal, Ivar Aanes, Ronny Sæther, Bernt‐Erik Henriksen, Snorre |
spellingShingle |
Bremset Hansen, Brage Herfindal, Ivar Aanes, Ronny Sæther, Bernt‐Erik Henriksen, Snorre Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore |
author_facet |
Bremset Hansen, Brage Herfindal, Ivar Aanes, Ronny Sæther, Bernt‐Erik Henriksen, Snorre |
author_sort |
Bremset Hansen, Brage |
title |
Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore |
title_short |
Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore |
title_full |
Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore |
title_fullStr |
Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore |
title_full_unstemmed |
Functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore |
title_sort |
functional response in habitat selection and the tradeoffs between foraging niche components in a large herbivore |
publisher |
Wiley |
publishDate |
2009 |
url |
http://dx.doi.org/10.1111/j.1600-0706.2009.17098.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1600-0706.2009.17098.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0706.2009.17098.x |
genre |
Svalbard svalbard reindeer |
genre_facet |
Svalbard svalbard reindeer |
op_source |
Oikos volume 118, issue 6, page 859-872 ISSN 0030-1299 1600-0706 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1600-0706.2009.17098.x |
container_title |
Oikos |
container_volume |
118 |
container_issue |
6 |
container_start_page |
859 |
op_container_end_page |
872 |
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1810482855707410432 |