Department of Natural Resource Ecology and Management, Oklahoma State University, 008C Agricultural Hall, Stillwater, OK, 74078, USA.
Department of Fisheries and Wildlife, Oregon State University, 497 SW Century Drive, Suite 105, Bend, OR, 97702, USA.
J Therm Biol. 2021 Jan;95:102791. doi: 10.1016/j.jtherbio.2020.102791. Epub 2020 Nov 19.
Temperature is increasingly recognized as an important component of wildlife habitat. Temperature is particularly important for avian nest sites, where extreme temperatures can influence adult behavior, embryonic development, and survival. For species inhabiting arid and semiarid climates, such as the scaled quail (Callipepla squamata), frequent exposure to extreme temperatures may increase the importance of the nest microclimate. Limited data suggest that scaled quail respond to temperature when selecting nest sites, and they are also known to respond to the presence of surface water and shrub cover on the landscape, two resources which may mitigate thermal stress. To better understand the role of temperature in nest site selection and survival, and to evaluate how other landscape resources may benefit nesting quail, we investigated nest site characteristics of scaled quail in southeastern New Mexico, USA. During the breeding seasons of 2018 and 2019 we located nests, monitored nest fate, and recorded thermal and vegetation characteristics at three spatial scales: the nest bowl, the nest microsite (area within 10 m of the nest bowl), and the landscape. We found that nest bowls moderated temperature relative to both the surrounding microsite and the broader landscape, remaining almost 5 °C cooler on average than the surrounding microsite at mid-day. Nest bowls also had taller, greater cover of vegetation compared to both the surrounding microsites and the landscape. Despite apparent selection for cooler temperatures and taller vegetation, these characteristics demonstrated a weak relationship with nest survival. Rather, nest survival was positively influenced by proximity to surface water and honey mesquite (Prosopis glandulosa), with survival decreasing with increasing distance from these features. Although the mechanism for this relationship is unclear, our results support the importance of temperature for nest site selection of ground-nesting birds in semiarid landscapes, and suggest further exploration of landscape-level sources of thermal mitigation.
温度越来越被认为是野生动物栖息地的一个重要组成部分。温度对鸟类巢穴尤其重要，极端温度会影响成鸟的行为、胚胎发育和生存。对于生活在干旱和半干旱气候中的物种，如鳞斑鹌鹑（Callipepla squamata），频繁暴露在极端温度下可能会增加巢内小气候的重要性。有限的数据表明，鳞斑鹌鹑在选择巢穴时会对温度做出反应，它们也会对景观中地表水和灌木覆盖的存在做出反应，这两种资源可能减轻热应激。为了更好地了解温度在巢址选择和生存中的作用，并评估其他景观资源如何使筑巢鹌鹑受益，我们在美国新墨西哥州东南部调查了鳞斑鹌鹑的巢址特征。在 2018 年和 2019 年的繁殖季节，我们定位了巢穴，监测了巢穴的命运，并记录了三个空间尺度上的热和植被特征：巢碗、巢微生境（巢碗周围 10 米以内的区域）和景观。我们发现，巢碗相对于周围的微生境和更广阔的景观调节了温度，平均比周围的微生境低近 5°C。巢碗的植被也更高、更茂密，与周围的微生境和景观相比。尽管对较凉爽的温度和更高的植被有明显的选择，但这些特征与巢的存活率呈弱相关。相反，巢的存活率受到与地表水和蜜腺洋槐（Prosopis glandulosa）接近的程度的正向影响，与这些特征的距离越远，存活率越低。虽然这种关系的机制尚不清楚，但我们的结果支持温度对半干旱景观中地面筑巢鸟类巢址选择的重要性，并表明需要进一步探索景观水平的热缓解来源。
