Dispersal characteristics of swift foxes

Abstract

From 1997 to 2001, we monitored movements of 109 adult and 114 juvenile swift foxes, Vulpes velox (Say, 1823), at study sites in Colorado, New Mexico, and Texas to determine patterns of dispersal. Significantly more male (93%) than female (58%) juveniles dispersed, and both sexes had similar bimodal dispersal patterns with peaks in September–October and January–February. Adult dispersal occurred more evenly throughout the year, and significantly more male (32%) than female (5%) adults dispersed. Adult males tended to disperse after the death of their mate. Of dispersing foxes with known fates, settlement percentages in new territories were similar between juvenile males and females (40% overall), but they were significantly lower than for adults (89%). All other dispersing foxes with known fates died. Among juvenile females with known fates, similar percentages of philopatric and dispersing foxes reproduced as yearlings (50% overall), so the benefits of dispersal versus philopatry were not clear. Although rarely reported for other species, adult males were an important dispersal cohort in swift foxes (43% of male dispersals and 25% of all dispersals). Because of the female-biased philopatry among swift foxes, dispersal of adult males likely decreased the chances for inbreeding (e.g., father–daughter breeding).

Sex‐biased natal dispersal and inbreeding avoidance in American black bears as revealed by spatial genetic analyses

“…Thus, the individuals most likely to engage in close inbreeding would be the most successful males and their daughters. For these males, secondary dispersal might provide a means to reduce the likelihood of mating with a daughter, such as that observed in swift foxes (Vulpes velox; Kamler et al 2004); however, we found no evidence of males abandoning their established home ranges after the age of six years (Costello 2008).…”

Genetic structure, spatial organization, and dispersal in two populations of bat‐eared foxes

“…Additionally, although frequent dispersal of adult males was reported in other fox species (Kamler et al. ,b), the frequent dispersal of adult females is unusual among canids in particular, and mammals in general. The dispersal patterns of bat‐eared foxes may be related to their unique evolutionary lineage (Maas and Macdonald ).…”

“…), including other fox species (Macdonald and Courtenay ; Kamler et al. ). Although sample size was too low for significance, males dispersed farther, on average, on Benfontein than PR.…”

Ectoparasite burden influences the denning behavior of a small desert carnivore

“…First, juveniles often remained spatially affiliated with adults for several weeks or months beyond the pup‐rearing season, though observed philopatry was highly variable (B. M. Kluever, unpublished data ), as has been observed in other canid investigations (Kamler et al. , Gosselink et al. ), But, when juveniles foxes did ultimately fully engage in dispersal behavior, they were likely faced with the challenge of locating areas containing suitable resources; it is intuitive that such forays would depress den use residency.…”

“…This finding may be attributed to several factors. First, juveniles often remained spatially affiliated with adults for several weeks or months beyond the pup-rearing season, though observed philopatry was highly variable (B. M. Kluever, unpublished data), as has been observed in other canid investigations (Kamler et al 2004, Gosselink et al 2010, But, when juveniles foxes did ultimately fully engage in dispersal behavior, they were likely faced with the challenge of locating areas containing suitable resources; it is intuitive that such forays would depress den use residency. Finally, in the system we investigated survival probability for juvenile foxes is markedly less than that of adults (Kluever and Gese 2017) and this likely influenced expected weekly residency times for this age class; an animal cannot re-use the same den if it has expired.…”