Habitat use by colonial tuco-tucos (Ctenomys sociabilis): Specialization, variation, and sociality

Abstract

Understanding habitat requirements has implications for numerous aspects of a species' biology, including where individuals live and how they behave. Specialization for mesic, resource-rich habitats known as mallines is thought to have favored group living in the colonial tuco-tuco (Ctenomys sociabilis), a subterranean rodent that is endemic to Neuquén Province in southwestern Argentina. To explore the proposed relationship between mallines and sociality in this species in greater detail, we characterized the habitats occupied by C. sociabilis at 3 locations representing the extremes of this species' geographic range. Specifically, plant composition and vegetative structure were characterized for 57 occupied burrow systems distributed across the 3 sampling localities. Our data indicate that C. sociabilis is not restricted to mallines. Although significant variation in vegetation was detected among the 3 study sites, the majority of active burrow systems surveyed at each site occurred in nonmallín habitats. In addition to providing the first species-wide survey of habitat use by C. sociabilis, our data yield new insights into the role of habitat specialization in promoting sociality in this behaviorally unusual species of ctenomyid rodent.