Norwegian Institute for Nature Research (NINA), Arctic Ecology Department, Polar Environmental Centre, N-9296 Tromsø, Norway.
Ecology. 2010 Mar;91(3):915-20. doi: 10.1890/09-0056.1.
Despite numerous studies of how climate change may affect life history of mammals, few have documented the direct impact of climate on behavior. The Arctic is currently warming, and rain-on-snow and thaw-freeze events leading to ice formation on the ground may increase both in frequency and spatial extent. This is in turn expected to be critical for the winter survival of arctic herbivores. Svalbard reindeer (Rangifer tarandus plathyrynchus) have small home ranges and may therefore be vulnerable to local "locked pasture" events (ice layers limit access to plant forage) due to ground-ice formation. When pastures are "locked," Svalbard reindeer are faced with the decision of staying and live off a diminishing fat store, or trying to escape beyond the unknown spatial borders of the ice. We demonstrate that Svalbard reindeer do the latter, as icing events cause an immediate increase in range displacement between 5-day observations. Population-level responses of previous icing events may therefore not accurately predict future responses if the spatial extent of icing increases. The impact of single events may be more severe if it exceeds the maximum movement distances, so that the spatial displacement strategy reported here no longer buffers climate effects.
尽管有许多研究探讨了气候变化如何影响哺乳动物的生活史，但很少有研究记录气候对行为的直接影响。北极地区正在变暖，导致地面结冰的雨雪和融冻事件的频率和空间范围预计都将增加。这反过来又可能对北极食草动物的冬季生存至关重要。斯瓦尔巴驯鹿（Rangifer tarandus plathyrynchus）的活动范围较小，因此由于地面结冰的形成，它们可能容易受到局部“锁定牧场”事件（冰层限制了对植物饲料的获取）的影响。当牧场被“锁定”时，斯瓦尔巴驯鹿面临着留在原地、消耗减少的脂肪储备的生存抉择，或者试图逃离未知的冰层空间边界。我们证明，斯瓦尔巴驯鹿选择了后者，因为结冰事件导致 5 天观测期内的活动范围立即增加。如果结冰的空间范围增加，以前结冰事件的种群水平反应可能无法准确预测未来的反应。如果单个事件的影响超过最大移动距离，那么这里报告的空间位移策略将不再缓冲气候影响，因此其影响可能更为严重。
