Corticosterone-induced stress responses modify the movement and spatial ecology of a fossorial reptile

Temporal variations in the health state of an individual, such as increased levels of the physiological stress resulting from environmental perturbations, might induce modifications in its strategies of movement and space use. However, these effects can vary depending on the environment, context, and lifestyle of each species. In this sense, fossorial species have been rarely examined, despite the fact that numerous environmental and human-derived factors may affect the quality of the underground soil environment. We examined whether an increased stress response affected the movement and spatial ecology of a strictly fossorial reptile, the amphisbaenian <i>Blanus cinereus</i>. We induced an increase of the stress responses in male amphisbaenians using sustained non-invasive corticosterone (CORT) supplementation. Then, we used passive integrated transponder (PIT) telemetry to track for 14 days the movements and space use of CORT-supplemented and control males, as well as unmanipulated females, while moving undisturbed underground in outdoor semi-natural enclosures. The CORT treatment decreased underground movement activity, distances moved, number of movements, and daily areas covered by CORT-supplemented males. However, although all males were in close proximity to females more often than to other males, there was no effect of the CORT supplementation of a male on its spatial relationships (distance and proximity) with conspecifics. An increased stress response may modify the underground movements and space use of fossorial reptiles, which may be a strategy to compensate for the negative effects of sustained stress on health, avoiding, for example, predation risk or the energetic costs of burrowing. Our study contributes to understanding the effects of soil environmental perturbations on the ecology of fossorial animals, and how these species might cope with stressful situations.