Wechat: https://mp.weixin.qq.com/s/qyBkWLusBa-HiSAMtAhyZQ

Kamal Atmeh, Anna Andruszkiewicz & Karol Zub

doi:10.1038/s41598-018-26057-5

生态学；进化

Published:

Direct phenological mismatch caused by climate change can occur in mammals that moult seasonally. Two colour morphs of the weasel Mustela nivalis (M. n.) occur sympatrically in Bia?owie?a Forest (NE Poland) and differ in their winter pelage colour: white in M. n. nivalis and brown in M. n. vulgaris. Due to their small body size, weasels are vulnerable to attacks by a range of different predators; thus cryptic coat colour may increase their winter survival. By analysing trapping data, we found that the share of white subspecies in the weasel population inhabiting Bia?owie?a Forest decreases with decreasing numbers of days with snow cover. This led us to hypothesise that selective predation pressure should favour one of the two phenotypes, according to the prevailing weather conditions in winter. A simple field experiment with weasel models (white and brown), exposed against different background colours, revealed that contrasting models faced significantly higher detection by predators. Our observations also confirmed earlier findings that the plasticity of moult in M. n. nivalis is very limited. This means that climate change will strongly influence the mortality of the nivalis-type due to prolonged camouflage mismatch, which will directly affect the abundance and geographical distribution of this subspecies.

根据《科学报告》发表的一项研究Climate change is affecting mortality of weasels due to camouflage mismatch，积雪天数减少可能降低冬季白毛伶鼬的存活率。波兰科学院的Karol Zub及同事认为冬季缩短后，白毛伶鼬的伪装性降低，使之更易受到捕猎者的攻击。

棕色夏季被毛和白色冬季被毛的伶鼬。

Karol Zub

伶鼬（Mustela nivalis ）有两个亚种，冬季被毛分别为白色和棕色，二者一般在同一栖息地共存。伶鼬通过使毛色与周围环境一致来达到伪装的目的，一般认为这样可以减少被捕猎的风险，提高生存几率。

在1997年到2007年间，作者在波兰比亚沃维耶扎原始森林（Bia?owie?a Forest）捕捉了95只冬季被毛为白色的伶鼬和23只冬季被毛为棕色的伶鼬，并对它们进行了记录。他们还研究了同期当地的气候数据，发现存在永久积雪的天数平均值从80天左右下降到了40天。这主要是因为近年来冬季整体缩短，积雪较早融化。研究人员发现，冬季被毛为白色的伶鼬与积雪天数同步减少。

白色冬季被毛的伶鼬。在对比鲜明的背景下，它们很显眼，而且更易被潜在的捕食者发现。

Karol Zub

作者利用白色和棕色伶鼬模型，检验毛色是否会影响狐狸、狼和猛禽等捕猎者发现伶鼬的几率。结果表明，相较于毛色与背景色一致的伶鼬模型，伪装较低的伶鼬模型更经常被捕猎者发现。以上发现意味着白毛伶鼬数量减少是因为积雪天数减少导致它们被捕猎者发现的几率上升。

      在无雪的环境下，局部换毛的伶鼬。

       Karol Zub

    （来源：科学网）