Sea or summit? Wild reindeer spatial responses to changing high‐arctic winters

Abstract Because of climate change, wildlife is facing altered environments, including profound shifts in temperature and precipitation regimes. In snow‐dominated ecosystems, winter warming and resulting changes in snowpack properties impact forage accessibility for ungulates—often for the worse. Th...

Full description

Bibliographic Details
Main Authors: Åshild Ønvik Pedersen, Larissa T. Beumer, Ronny Aanes, Brage B. Hansen
Format: Article
Language:English
Published: Wiley 2021-12-01
Series:Ecosphere
Subjects:
Online Access:https://doi.org/10.1002/ecs2.3883
_version_ 1798015487944163328
author Åshild Ønvik Pedersen
Larissa T. Beumer
Ronny Aanes
Brage B. Hansen
author_facet Åshild Ønvik Pedersen
Larissa T. Beumer
Ronny Aanes
Brage B. Hansen
author_sort Åshild Ønvik Pedersen
collection DOAJ
description Abstract Because of climate change, wildlife is facing altered environments, including profound shifts in temperature and precipitation regimes. In snow‐dominated ecosystems, winter warming and resulting changes in snowpack properties impact forage accessibility for ungulates—often for the worse. The potential of individuals and populations to buffer negative fitness effects of harsh winters with “basal ice” (i.e., ice on the ground) and/or a harder or deeper snowpack depends on their ability to adjust behaviorally through changes in diet, dispersal, or small‐scale habitat use. Here, we use ten years of late winter snowpack monitoring and population census data from three neighboring, semi‐isolated coastal populations of high‐arctic wild Svalbard reindeer to explore small‐scale space use responses to annual variation in late winter‐foraging conditions. Based on location data from the population censuses, we roughly classified individuals' spatial foraging strategy (i.e., habitat use) during late winter into “tundra” (foraging on tundra plains), “mountain” (foraging at high elevations, with low plant biomass but less snow and ice), or “shore” (foraging along the seashore, subsidizing terrestrial food with kelp and seaweed). Using multinomial logistic regression, we modeled the probability of reindeer adopting either of these strategies as a function of density‐dependent winter severity. Our results suggest that effects of winter severity on habitat use are density‐dependent and that snowpack depth and hardness (excluding basal ice, measured as “integrated ram hardness,” IRH) have stronger influence on reindeer foraging behavior than basal ice, at least at such spatial scales. Particularly, high IRH increased the probability of reindeer seeking high‐elevation and steep terrain instead of tundra lowlands, but not at low population density, that is, when competition for food is negligible. This strategy was most pronounced among adult males, possibly reflecting their risk‐prone behavior and/or reduced competitiveness related to lack of antlers during winter. This study demonstrates important patterns of temporal, spatial, and demographic variation in reindeer's winter‐foraging strategies, adding novel, nuanced insights into how climate change affects spatial processes in isolated ungulate populations. The results add to the impression of considerable behavioral flexibility, which may aid buffering the negative fitness effects of complex changes in foraging conditions due to environmental changes.
first_indexed 2024-04-11T15:35:19Z
format Article
id doaj.art-14a0338d3715468ba22b9b8c875ef5f3
institution Directory Open Access Journal
issn 2150-8925
language English
last_indexed 2024-04-11T15:35:19Z
publishDate 2021-12-01
publisher Wiley
record_format Article
series Ecosphere
spelling doaj.art-14a0338d3715468ba22b9b8c875ef5f32022-12-22T04:16:01ZengWileyEcosphere2150-89252021-12-011212n/an/a10.1002/ecs2.3883Sea or summit? Wild reindeer spatial responses to changing high‐arctic wintersÅshild Ønvik Pedersen0Larissa T. Beumer1Ronny Aanes2Brage B. Hansen3Fram Centre Norwegian Polar Institute Tromsø 9296 NorwayFram Centre Norwegian Polar Institute Tromsø 9296 NorwayFram Centre Norwegian Polar Institute Tromsø 9296 NorwayNorwegian Institute for Nature Research Trondheim 7485 NorwayAbstract Because of climate change, wildlife is facing altered environments, including profound shifts in temperature and precipitation regimes. In snow‐dominated ecosystems, winter warming and resulting changes in snowpack properties impact forage accessibility for ungulates—often for the worse. The potential of individuals and populations to buffer negative fitness effects of harsh winters with “basal ice” (i.e., ice on the ground) and/or a harder or deeper snowpack depends on their ability to adjust behaviorally through changes in diet, dispersal, or small‐scale habitat use. Here, we use ten years of late winter snowpack monitoring and population census data from three neighboring, semi‐isolated coastal populations of high‐arctic wild Svalbard reindeer to explore small‐scale space use responses to annual variation in late winter‐foraging conditions. Based on location data from the population censuses, we roughly classified individuals' spatial foraging strategy (i.e., habitat use) during late winter into “tundra” (foraging on tundra plains), “mountain” (foraging at high elevations, with low plant biomass but less snow and ice), or “shore” (foraging along the seashore, subsidizing terrestrial food with kelp and seaweed). Using multinomial logistic regression, we modeled the probability of reindeer adopting either of these strategies as a function of density‐dependent winter severity. Our results suggest that effects of winter severity on habitat use are density‐dependent and that snowpack depth and hardness (excluding basal ice, measured as “integrated ram hardness,” IRH) have stronger influence on reindeer foraging behavior than basal ice, at least at such spatial scales. Particularly, high IRH increased the probability of reindeer seeking high‐elevation and steep terrain instead of tundra lowlands, but not at low population density, that is, when competition for food is negligible. This strategy was most pronounced among adult males, possibly reflecting their risk‐prone behavior and/or reduced competitiveness related to lack of antlers during winter. This study demonstrates important patterns of temporal, spatial, and demographic variation in reindeer's winter‐foraging strategies, adding novel, nuanced insights into how climate change affects spatial processes in isolated ungulate populations. The results add to the impression of considerable behavioral flexibility, which may aid buffering the negative fitness effects of complex changes in foraging conditions due to environmental changes.https://doi.org/10.1002/ecs2.3883adaptationArcticbehavioral plasticityclimate changerain‐on‐snowRangifer tarandus platyrhynchus
spellingShingle Åshild Ønvik Pedersen
Larissa T. Beumer
Ronny Aanes
Brage B. Hansen
Sea or summit? Wild reindeer spatial responses to changing high‐arctic winters
Ecosphere
adaptation
Arctic
behavioral plasticity
climate change
rain‐on‐snow
Rangifer tarandus platyrhynchus
title Sea or summit? Wild reindeer spatial responses to changing high‐arctic winters
title_full Sea or summit? Wild reindeer spatial responses to changing high‐arctic winters
title_fullStr Sea or summit? Wild reindeer spatial responses to changing high‐arctic winters
title_full_unstemmed Sea or summit? Wild reindeer spatial responses to changing high‐arctic winters
title_short Sea or summit? Wild reindeer spatial responses to changing high‐arctic winters
title_sort sea or summit wild reindeer spatial responses to changing high arctic winters
topic adaptation
Arctic
behavioral plasticity
climate change
rain‐on‐snow
Rangifer tarandus platyrhynchus
url https://doi.org/10.1002/ecs2.3883
work_keys_str_mv AT ashildønvikpedersen seaorsummitwildreindeerspatialresponsestochanginghigharcticwinters
AT larissatbeumer seaorsummitwildreindeerspatialresponsestochanginghigharcticwinters
AT ronnyaanes seaorsummitwildreindeerspatialresponsestochanginghigharcticwinters
AT bragebhansen seaorsummitwildreindeerspatialresponsestochanginghigharcticwinters