Gestation, maternal behaviour, growth and development in the subterranean caviomorph rodent Ctenomys mendocinus (Rodentia, Hystricognathi, Ctenomyidae)

Abstract

The first information on the gestation period, maternal behaviour, neonatal development and growth of the subterranean caviomorph rodent Ctenomys mendocinus Philippi, 1869, is reported herein. My hypothesis was that, despite its belonging to a typically precocial suborder, the life history traits of C. mendocinus would favour its altricial condition. Th e off spring of C. mendocinus were categorized as altricial by using two diff erent classifi cation systems. Th is condition was also refl ected in maternal care. Females built large nests (2000 cm 3 ) where, after a long gestation period (95.9 days), they gave birth to litters of blind pups, half-naked, with external ear meatus open and good physical coordination. Th e mothers suckled the off spring in long bouts (19.9 min), retrieved their pups, and these showed no tactics to reduce the suckling bout. Overall, evidence was consistent with the hypothesis analyzed, although particularities found, e.g. some precocial traits, suggest the existence in C. mendocinus of a trade-off between the constraints and advantages related to its subterranean way of life and the phylogenetic inertia typical of caviomorphs.