title: Effect of ambient temperature on evaporative water loss in the subterranean rodent Ctenomys talarum.
abstract: Subterranean rodents face unique thermoregulatory challenges. Evaporative water loss (EWL) is a crucial mechanism for maintaining heat balance in endotherms subjected to heat stress but also leads to potential dehydration. EWL depends on gradients of temperature and humidity between the surface of the individual and the surrounding environment. Underground burrows generally provide a stable water vapor saturated atmosphere which may impede evaporative heat loss (EHL). This will mainly occur when ambient temperature exceeds the upper limit of individual's thermoneutral zone, or when body temperature rises as result of digging activities. Here we evaluate the effect of ambient temperature on EWL and energy metabolism in the subterranean rodent Ctenomys talarum (tuco-tucos), which inhabits sealed burrows, but makes an extensive use of the aboveground environment. We observed that EWL is increased when ambient temperature rises above thermoneutrality; below this point, evaporation remains stable. Though EWL contributes to total heat loss by increasing ∼1.3 times at 35°C, dry thermal conductance is raised four times. In tuco-tucos' burrows both non-evaporative and, to some extent, evaporative and behavioral mechanisms are essential for body temperature regulation, preventing overheating at high ambient temperatures in a water vapor-saturated atmosphere.
authors.affiliation: Grupo de Ecología Fisiológica y del Comportamiento, Departamento de Biología, Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de Mar del Plata, Mar del Plata, Argentina. Electronic address: mbbaldo@mdp.edu.ar.
authors.forename: María Belén
authors.initials: MB
authors.lastname: Baldo
authors.affiliation: Grupo de Ecología Fisiológica y del Comportamiento, Departamento de Biología, Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
authors.forename: C Daniel
authors.initials: CD
authors.lastname: Antenucci
authors.affiliation: Grupo de Ecología Fisiológica y del Comportamiento, Departamento de Biología, Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
authors.forename: Facundo
authors.initials: F
authors.lastname: Luna
mesh_terms: D003883:Arthrodermataceae / Q000502:physiology*; D001831:Body Temperature; D017753:Ecosystem; D006358:Hot Temperature; D014870:Water Loss, Insensible
keywords: Burrow; Ctenomys talarum; Evaporative water loss; Heat dissipation; Metabolic rate; Temperature