Cuidado e investimento parental em raposas-do-campo (Lycalopex vetulus)

Abstract

Parental care is defined as any behavior exhibited by parents that may increase the survival and growth of their offspring. In mammals, biparental care is observed only in 5-10% of species, including canids, a group that includes wolves, coyotes, jackals and foxes. The hoary fox (Lycalopex vetulus) is a canid endemic to the Cerrado, reproducing seasonally and giving birth to litters of one to five pups, which are usually born inside six-banded armadillo (Euphractus sexcinctus) burrows. Given the hoary fox ecology, little is known about parental investment in this species. Therefore, the aim of this study was to describe how parental care is carried out in hoary foxes and its influence on reproductive success. Between September and December 2022, burrows within litters of three pairs of hoary foxes were monitored in pastures in the municipality of Corumbaíba, Goiás, Brazil. Using the focal scanning method, an ethogram of parents behavior in the pups’ burrows area. Additionally, using locations provided by GPS collars, it was analyzed the degree of overlap between the home ranges of four pairs during the parental and non-parental periods between 2020 and 2022. During the first stage of pup development (1st to 7th week) both sexes spent similar amounts of time in the burrow area, however, in the second stage (8th to 14th week) males spent significantly more time in the burrow area (t= 5,168, p= 0,02). Throughout all the pups' development stages, during the day, parents visited the burrow area less frequently, while at night both sexes visited more (z= 5,383, p < 0.001). During night time, duration of visits to the burrow was shorter (t= -5,823, p < 0.001), but despite both sexes made longer visits during the day, this effect was even stronger for males (t= -2,148, p= 0,03). A total of 26 parental care behaviors were recorded, organized into ten categories, in which males performed mainly behaviors related to protection, and females utilized the same burrow as pups. The mean overlap of pairs home range during parental period was 84.5% and 88.2% in non-parental period. These results demonstrate the importance of parental investment from both females and males hoary foxes. During the first few weeks of the pups' lives, females are essential in offspring care, due to the pups' dependence on maternal milk. As the cubs grow up, they leave the burrows and start feeding on solid items, males invest more time in the burrow area protecting and bringing food. Although both sexes take care and allocate a similar amount of time in raising pups, males might reduce sexual conflict over the female's parental investment by spending more time in the burrow area after the second stage of pups’ development. Furthermore, the presence of both parents sharing the same territory seems to ensure the pups survival, since a widowed female was unable to successfully raise her litter after the male death. The results presented in this study may be useful to better understand the parental behavior and natural history of less social canids, in addition to subsidizing conservation actions for the species.