Data for the detection of the boreal chorus frog (Pseudacris maculata) using environmental DNA and call surveys at 180 ponds sampled in 2017-2018 in southeastern Québec, Canada

The boreal chorus frog (Pseudacris maculata) is at risk of extinction in parts of its range in Canada. Our objectives were to quantify the influence of local and landscape characteristics on the occurrence of the species in wetlands in southern Québec. We hypothesized that site occupancy depends on local characteristics and landscape characteristics contributing to site connectivity. We developed an environmental DNA (eDNA) method to detect the species and compared the detection probability of this method to traditional call surveys. We collected water samples at a total of 180 sites (90 in 2017, 110 in 2018), whereas we surveyed a subset of 63 sites using both eDNA and call surveys in 2018. Site occupancy varied across years, but was higher in sites where the species had been previously detected during the last 12 years by other studies. Site occupancy did not vary with other local and landscape characteristics, in part due to an apparent decrease in the number of sites occupied by the species since the last 12 years. Detection probability via eDNA (0.81; 95% CI: [0.31; 0.98]) did not differ from that of call surveys (0.62; 95% CI: [0.25; 0.89]). To identify the optimal sampling period for the boreal chorus frog, future studies should estimate the detection probability of eDNA during the breeding season and the larval development period of the species.

Methods
The data presented in the files include the detection data of the boreal chorus frog (Pseudacris maculata) using environmental DNA (eDNA) and call surveys in southeastern Québec, Canada. A total of 180 ponds were sampled during the breeding season in 2017 and 2018 with eDNA, whereas a subset of these ponds were also sampled with call surveys.

北方鸣蛙（Pseudacris maculata）在加拿大境内的部分分布区域面临灭绝风险。本研究旨在量化局地与景观特征对魁北克南部湿地中该物种种群出现情况的影响，提出假说：生境占据率取决于局地特征以及有助于生境连通性的景观特征。我们开发了环境DNA（environmental DNA, eDNA）检测方法以识别该物种，并将该方法的检测概率与传统鸣声调查法进行了对比。本研究共计在180个样点采集了水样（2017年90个，2018年110个），并于2018年采用eDNA与鸣声调查法对其中63个样点子集开展了双重调查。生境占据率随年份有所波动，但在过往12年中其他研究已检测到该物种的样点中，占据率更高。生境占据率未随其他局地与景观特征发生显著变化，这在一定程度上是因为过去12年间该物种占据的样点数量明显减少。eDNA检测法的检测概率（0.81；95%置信区间：[0.31, 0.98]）与鸣声调查法（0.62；95%置信区间：[0.25, 0.89]）并无显著差异。为确定北方鸣蛙的最佳采样时段，未来研究应估算该物种在繁殖季与幼体发育阶段的eDNA检测概率。

研究方法
本数据集文件中包含加拿大魁北克东南部地区采用环境DNA（environmental DNA, eDNA）与鸣声调查法获取的北方鸣蛙（Pseudacris maculata）检测数据。2017年与2018年繁殖季期间，共计对180个池塘开展了eDNA采样，其中部分池塘同时采用鸣声调查法开展了采样。