title: Phenotypic flexibility in the energetic strategy of the greater white-toothed shrew, Crocidura russula.
abstract: The balance between energetic acquisition and expenditure depends on the amount of energy allocated to biological functions such as thermoregulation, growth, reproduction and behavior. Ambient temperature has a profound effect on this balance, with species inhabiting colder climates often needing to invest more energy in thermoregulation to maintain body temperature. This leads to local behavioral and physiological adaptations that increase energetic efficiency. In this study, we investigated the role of activity, behavior and thermogenic capacity in the ability of the greater white-toothed shrew, Crocidura russula, to cope with seasonal changes. Individuals were captured in the Sintra-Cascais Natural Park, a Mediterranean region, and separated into three experimental groups: a control group, acclimated to a 12L:12D photoperiod and temperature of 18-20°C; a winter group, acclimatized to natural winter fluctuations of light and temperature; and a summer group, acclimatized to natural summer fluctuations of light and temperature. No differences were found in resting metabolic rate and nonshivering thermogenesis between the three groups. However, winter shrews significantly reduced their activity, particularly at night, compared to the control and summer groups. Differences in torpor use were also found between groups, with winter shrews entering torpor more frequently and during shorter periods of time than summer and control shrews. Our results indicate C. russula from Sintra relies on the flexibility of energy saving mechanisms, namely daily activity level and torpor use, to cope with seasonal changes in a Mediterranean climate, rather than mechanisms involving body heat production.
authors: CESAM - Centre for Environmental and Marine Studies, Department of Animal Biology, Faculty of Sciences, University of Lisbon, C2 building, 3rd floor, Campo Grande, 1749-016 Lisbon, Portugal. Electronic address: flavioagoliveira@gmail.com.
authors: Flávio G
authors: FG
authors: Oliveira
authors: CESAM - Centre for Environmental and Marine Studies, Department of Animal Biology, Faculty of Sciences, University of Lisbon, C2 building, 3rd floor, Campo Grande, 1749-016 Lisbon, Portugal. Electronic address: joaquim.tapisso@gmail.com.
authors: Joaquim T
authors: JT
authors: Tapisso
authors: CESAM - Centre for Environmental and Marine Studies, Department of Animal Biology, Faculty of Sciences, University of Lisbon, C2 building, 3rd floor, Campo Grande, 1749-016 Lisbon, Portugal.
authors: Rita I
authors: RI
authors: Monarca
authors: CESAM - Centre for Environmental and Marine Studies, Department of Animal Biology, Faculty of Sciences, University of Lisbon, C2 building, 3rd floor, Campo Grande, 1749-016 Lisbon, Portugal.
authors: Ana M
authors: AM
authors: Cerveira
authors: CESAM - Centre for Environmental and Marine Studies, Department of Animal Biology, Faculty of Sciences, University of Lisbon, C2 building, 3rd floor, Campo Grande, 1749-016 Lisbon, Portugal.
authors: Maria L
authors: ML
authors: Mathias
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001835:Body Weight; D004734:Energy Metabolism; D005260:Female; D008297:Male; D010641:Phenotype; D012621:Seasons; D012788:Shrews / Q000502:physiology*; D022722:Thermogenesis; D064348:Torpor
keywords: Behavioral activity; Daily torpor; Metabolism; Seasonality