Nutritional responses to different diet quality in the subterranean rodent Ctenomys talarum (tuco-tucos).

Nutritional response to different diet quality was examined in the subterranean rodent Ctenomys talarum (tuco-tuco). Animals maintained in captive conditions were fed with three plant species that differed in their fibre content. Tuco-tucos showed the ability to perform adjusts in short time lapse in response to diet quality; food ingestion, egestion and feces ingestion changed in animals under different plant species diets.

Phenotypic plasticity in response to low quality diet in the South American omnivorous rodent Akodon azarae (Rodentia: Sigmodontinae).

We studied the responses in the omnivorous rodent A. azarae submitted to a low quality diet at morphological, physiological and biochemical levels. At short term, a decrease in body mass occurred.

Seasonal changes in body composition of Ctenomys talarum (Rodentia: Octodontidae): an herbivore subterranean rodent.

Ctenomys talarum is a subterranean herbivorous rodent whose burrow systems exhibit particular characteristics, distinct from other subterranean environments. We studied seasonal variation in body composition of C. talarum in relation to energetic requirements.

Use of chemical communication by the subterranean rodent Ctenomys talarum (tuco-tuco) during the breeding season.

Solitary subterranean rodents with a low frequency of direct contact between conspecifics are expected to use chemical communication to coordinate social and reproductive behavior. We examined whether reproductive tuco-tucos (Ctenomys talarum) were able to discriminate the reproductive condition, sex, and source population of conspecifics by means of chemical cues contained in urine, feces, soiled shavings, or anogenital secretions. During preference tests in which animals had direct contact with these chemical cues, tuco-tucos were able to determine the reproductive condition of opposite sex conspecifics independent of the source of odor.

Phenotypic flexibility of digestive morphology and physiology of the South American omnivorous rodent Akodon azarae (Rodentia: Sigmodontinae).

We have determined the occurrence of responses at different levels (morphological, physiological and biochemical) in the omnivorous rodent Akodon azarae upon cold acclimation (15 degrees C). A short-term enhancement in food consumption appeared to account for the maintenance of both mass and body composition. At the morphological level, the main response was an increase in the dimensions of small intestine, which constitutes the section of the gut where absorption and secretion take place.

Energetic expenditure during vocalization in pups of the subterranean rodent Ctenomys talarum.

Theoretical signaling models predict that to be honest, begging vocalizations must be costly. To test this hypothesis, oxygen consumption was measured during resting and begging (i.e.

Thermoregulatory development in pups of the subterranean rodent Ctenomys talarum.

The effect of the mother's contact and huddling with nest mates on the mass-specific metabolic rate (RMR) and body temperature (T(b)) of pups of Ctenomys talarum from 2 to 45 days of age was evaluated at ambient temperatures (T(a)) within and below the adult thermoneutrality range (25 and 19 degrees C, respectively, the latter corresponding to the one recorded in burrows during the spring, when pups are born). Under these conditions, we recorded the percentage of time that pups spent huddled with nest mates, with their mother and suckling. At 19 degrees C, huddling and contact with the mother significantly reduced pups' body heat loss until they were 15 days old but did not affect their RMR.

Bioenergetics of reproduction and pup development in a subterranean rodent (Ctenomys talarum).

The objective of this study was to evaluate the maternal costs of reproduction and pup development in the subterranean rodent Ctenomys talarum (Thomas 1898). Statistical differences were detected in whole-animal metabolic rates between nonreproductive and pregnant or lactating females. Whole-animal metabolic rates during pregnancy and lactation were 128% and 151% of the resting metabolic rate (RMR) observed in nonreproductive females.