Data from: Female Soay sheep do not adjust their maternal care behaviour to the quality of their home range

Resource availability, through its impact on the costs and benefits of parental care, is expected to influence parental care behavior. There has, to our knowledge, been no attempt to understand how variation in the resource use of wild individuals influences parental care behavior. To understand how natural resource variability affects maternal care in female St. Kilda Soay sheep, we selected 69 females whose home ranges varied in quality (measured as the mean percentage cover of Holcus lanatus), and recorded the behavior of each individual and her lamb over the period of maternal care. Home range quality did not influence suckling or non-suckling behaviors of the female or her lamb, suggesting that maternal care did not vary with a female's access to resources. Growth rate analyses confirmed the behavioral results, with no association between home range quality and the weight gain of lambs between birth and weaning. This work suggests that female Soay sheep faced with poorer resources do not favor their own future success over that of their lamb, and thereby do not exhibit a conservative reproductive strategy. This may be because when resource levels are high during the summer, females are able to offset the costs of lactation by consuming additional resources, regardless of the location of their home range. Our results suggest that more studies characterizing the environment experienced by individual animals will be necessary to fully understand how individuals alter their behavior in response to temporal and spatial variation in the environment.资源可获得性通过影响双亲抚育（parental care）的成本与收益，可对母育行为（maternal care）产生调控作用。据我们所知，目前尚无研究探讨野生个体的资源利用差异如何影响母育行为。为阐明自然资源变异性如何影响圣基达岛索艾羊（St. Kilda Soay sheep）的母育行为，我们选取了69只雌性个体，其家域（home range）质量以绒毛草（Holcus lanatus）的平均盖度作为衡量指标，并在母育期内记录了每只母羊及其羔羊的行为。家域质量并未对母羊或羔羊的哺乳与非哺乳行为产生影响，这表明母育行为并未随母羊的资源可获得性水平发生变化。生长速率分析验证了上述行为学结果：家域质量与羔羊出生至断奶期间的体重增益并无关联。本研究表明，当索艾羊雌性个体面临资源匮乏的环境时，并不会优先保障自身未来的繁殖成功率而非羔羊的存活，因此并未采取保守的繁殖策略。这一现象的潜在原因可能为：夏季资源充足时，母羊可通过摄取额外食物补偿泌乳成本，且不受家域位置的限制。我们的研究结果提示，未来需开展更多针对个体动物所处环境特征的研究，方能全面理解个体如何响应环境的时空变异以调整自身行为。