Spatial and thermal blanding's turtle data

Declining reptilian populations have been a growing concern over the last
couple of decades. One such declining species of concern, the Blanding’s
turtle (Emydoidea blandingii), occurs as isolated populations in North
American prairie-wetlands and is at risk of extirpation due to habitat
loss and fragmentation, and increased predator (e.g. racoons, coyotes)
populations due to supplemented resources in urban environments. To help
mitigate declining populations, wildlife managers have invested in the
conservation of this species through head-starting (i.e. reared in
ex-situ) and juvenile release programs to augment wild Blanding’s turtle
populations. However, much of their spatial and winter/thermal ecology is
understudied, and data for juveniles, and juveniles reared in ex-situ is
especially scarce, yet this information is imperative to understanding
shortfalls and improving head-starting efforts in the future. In spring
2016 (RR2016) and 2017 (RR2017) we released a cohort (n=12 each year) of
head-started juvenile Blanding’s turtles equipped with radio transmitters
and temperature dataloggers into a prairie-wetland in the greater Chicago
region, North America. Using ground-based radio telemetry, we determined
seasonal movement areas (SMAs; spring, summer, and fall) and annual home
ranges (AHRs) for both RR2016 and RR2017 cohorts via Kernel Density (KD)
estimates. We also investigated the thermal characteristics of
overwintering for both juvenile cohorts. We found that SMAs for the RR2016
cohort, but not for the RR2017 cohort, significantly differed across
seasons for most SMA estimators. We also found that juveniles in both
cohorts not only survived overwintering but also displayed similar
overwintering phenology (i.e. initiation: October-November; termination:
April) and temperature variation as Blanding’s turtles adults in other
studies. Overall, our results indicate that head-started juvenile
Blanding’s turtles may be able to acclimatize quickly to their natural
environment post-release. Our study provides evidence of the efficacy of
well-developed head-starting programs that aim to augment and preserve
imperiled turtle populations.

过去几十年里，爬行动物种群数量下降日益引起人们的关注。其中一种受关注的濒危物种是Blanding's龟（Emydoidea blandingii），其种群在北美草原湿地呈孤立分布，由于栖息地丧失与破碎化，以及城市环境中资源补充导致捕食者（如浣熊、郊狼）数量增加，该物种面临灭绝风险。为缓解种群数量下降，野生动物管理者通过头胎培育（head-starting，即异地饲养）和幼龟放归项目来增加野生Blanding's龟的种群数量。然而，其空间生态与冬季/热生态的大部分研究尚不充分，尤其是幼龟及异地饲养幼龟的数据极为匮乏，而这些信息对于理解现有不足及未来改进头胎培育工作至关重要。2016年春季（RR2016）和2017年春季（RR2017），我们将配备无线电发射器和温度数据记录仪的两组头胎培育幼龟（每年12只）放归到北美大芝加哥地区的一处草原湿地中。通过地面无线电遥测技术，我们利用核密度（Kernel Density，简称KD）估计法确定了RR2016和RR2017队列的季节性活动区域（seasonal movement areas，简称SMAs；春季、夏季、秋季）及年度家域（annual home ranges，简称AHRs）。我们还研究了两组幼龟越冬的热特征。我们发现，对于大多数SMAs估计方法而言，RR2016队列的SMAs存在显著的季节差异，而RR2017队列则无此差异。此外，两组幼龟不仅成功越冬，其越冬物候（即开始时间：10-11月；结束时间：4月）及温度变化与其他研究中Blanding's龟成体的表现相似。总体而言，我们的结果表明，头胎培育的Blanding's幼龟在放归后可能能够快速适应自然环境。本研究为旨在增加和保护濒危龟类种群的成熟头胎培育项目的有效性提供了证据。