Global positioning system (GPS) technology is increasingly used to study animal behavior. However, some animals exhibit behaviors that may result in the failure to acquire a GPS position, such as for species with underground denning behavior. This creates a challenge for researchers to identify the timing of important life-history events such as birth. Here, we tested if information gaps arising from unsuccessful GPS positions, in connection with intrinsic and extrinsic factors, can identify parturition events in an underground denning species, the red fox. Using data from 30 GPS collared female red foxes during the approximate parturition period of 1 March–31 May, we calculated the proportion of successful GPS positions per day. We then compared the patterns of successful GPS positions for females of known reproductive status to those known not to have reproduced and a subset of females for which reproductive status was unknown. Females confirmed to have pups ( n = 11) and two females of unknown reproductive status showed a significant difference in the proportion of successful GPS positions compared to females without pups, illustrating that parturition and denning activity could be identified from GPS data. None of the 12 subadult females were identified as denning. Parturition date, identified as the day with the lowest GPS fix rate within the five-day period with the lowest proportion of successful GPS positions, ranged from 20 March–14 May, with a mean parturition date of 12 April. We, therefore, conclude that important biological information, such as reproductive status and parturition dates, can be identified from patterns of missing GPS positions for some underground denning species.

中文翻译：

---

钻进洞里：缺少 GPS 位置揭示了一种地下洞穴物种红狐的出生日期

全球定位系统 (GPS) 技术越来越多地用于研究动物行为。然而，一些动物表现出可能导致无法获取 GPS 位置的行为，例如具有地下洞穴行为的物种。这给研究人员确定重要的生活史事件（如出生）的时间带来了挑战。在这里，我们测试了不成功的 GPS 位置引起的信息差距，与内在和外在因素有关，是否可以识别地下栖息物种红狐的分娩事件。我们使用大约 3 月 1 日至 5 月 31 日分娩期间 30 只戴 GPS 项圈的雌性赤狐的数据，计算了每天 GPS 定位成功的比例。然后，我们将已知生殖状态的雌性与已知未繁殖的雌性以及生殖状态未知的雌性子集的成功 GPS 位置模式进行了比较。确认有幼崽的雌性 (n = 11) 和两只生殖状态未知的雌性与没有幼崽的雌性相比，GPS 定位成功的比例有显着差异，说明可以从 GPS 数据中识别分娩和筑巢活动。12 只亚成年雌性中没有一只被鉴定为丹宁。分娩日期，确定为五天内 GPS 定位率最低且 GPS 定位成功比例最低的那一天，范围为 3 月 20 日至 5 月 14 日，平均分娩日期为 4 月 12 日。因此，我们得出结论，重要的生物学信息，