Padrão de uso de tocas por raposas-do-campo (Lycalopex vetulus)

Abstract

Dens are indispensable resources for a variety of species, used as shelter, reproduction, protection against weather conditions, predators, and competitors. Den density and philopatry are determined by the number of dens located in portions of home ranges and the frequency of use, respectively. The hoary fox (Lycalopex vetulus), a neotropical canid endemic to Brazil, heavily relies on dens for survival, yet the spatial dynamics of den use within its home range are unknown. Therefore, this study aimed to quantify and describe den use by hoary foxes and its relationship with home ranges to test the following hypotheses: (1) low den fidelity by hoary foxes; and (2) den density predominantly found in the core areas of home ranges. To describe den use, 20 individuals were monitored using Very High-Frequency (VHF) collars and Global Positioning System (GPS) in two agroecosystem regions in southeastern Goiás. Data collection occurred between 2007 and 2016 in the Cumari municipality region and between 2020 and 2022 in the Corumbaíba municipality region, Goiás, Brazil. During monitoring, used dens were identified, mapped, and dated considering an annual reproductive cycle spanning from May to April. Identified dens were categorized as new, reused, or shared. The home range of each individual was estimated and divided into regions, representing nuclear and peripheral areas. This representation was performed to count the number of dens in each region within the home range. There was little variation between reproductive cycles in both study areas, with an average of 4.1 ± 2.1 (n = 90) dens per cycle in Limoeiro and 11.5 ± 2.4 (n = 89) in Pontal. The majority of used dens were new dens (Limoeiro: 58,89%, n = 90; Pontal: 89,89%, n = 89), as opposed to old (reused) dens (Limoeiro: 8,89%, n = 90; Pontal: 19,10%, n = 89). Shared dens were generally used by mating pairs. Concerning location within home ranges, dens were predominantly found in nuclear areas (Limoeiro: median 4.93, IQR = 2,3-17; Pontal: mean 20.81 ± 11.25), compared to peripheral areas (Limoeiro: median 0.25, IQR = 0-0.83; Pontal: mean 1.08 ± 0.68). These findings provide a starting point for deepening understanding of the relationship between den use and home ranges, not only for this little-known canid but also for other species utilizing dens that may be targeted for conservation strategies.