Cost of living in free-ranging degus (Octodon degus): seasonal dynamics of energy expenditure

Bozinovic F.; Bacigalupe, LD; Vasquez, RA; Visser, GH; Veloso C.; Kenagy, GJ

Abstract

Animals process and allocate energy at different seasons at variable rates, depending on their breeding season and changes in environmental conditions and resulting physiological demands. Overall total energy expenditure, in turn, should either increase in some seasons due to special added demands (e.g. reproduction) or it could simply remain at about the same level, in which case the animals must show compensatory rebalancing of other expenditures that can be reduced. To test for the alternative hypotheses of seasonal variability or compensation, we measured total daily energy expenditure (DEE) in free-living degus (Octodon degus) at four seasons and followed this with determinations of basal metabolic rate (BMR) in the laboratory in the same individuals. DEE varied seasonally but was only significantly different (lower) in summer (non-breeding season), with a DEE:BMR ratio of only 1.6, whereas autumn, winter and spring DEE values were statistically indistinguishable from one another and showed DEE:BMR ratios ranging from 1.9 to 2.2. Our values of DEE in the field fall within the broad range of allometric expectation for herbivorous mammals in general, but the ratios of DEE:BMR are lower than expected. This, together with the lack of strong major shifts in total levels of DEE, suggests that degus are showing compensatory shifts among various categories of energy expenditure that allow them to manage their overall energy balance by minimizing total expenditure. © 2003 Elsevier Inc. All rights reserved.

Más información

Título según WOS: Cost of living in free-ranging degus (Octodon degus): seasonal dynamics of energy expenditure
Título según SCOPUS: Cost of living in free-ranging degus (Octodon degus): Seasonal dynamics of energy expenditure
Título de la Revista: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY
Volumen: 137
Número: 3
Editorial: Elsevier Science Inc.
Fecha de publicación: 2004
Página de inicio: 597
Página final: 604
Idioma: English
URL: http://linkinghub.elsevier.com/retrieve/pii/S1095643303003945
DOI:

10.1016/j.cbpb.2003.11.014

Notas: ISI, SCOPUS