Browsing by Author "BOZINOVIC, F"

Now showing 1 - 4 of 4
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    BODY SIZE, ENERGETIC AND FORAGING MODE OF RAPTORS IN CENTRAL CHILE - AN INFERENCE
    (1988) BOZINOVIC, F; MEDEL, RG
    An inferential analysis of the foraging mode (opportunist or mediate by prey selection) of a taxonomic assemblage of raptors in central Chile was conducted. The analysis of energetic aspects such as daily requirements of predators and energy supplied by the preys, with estimations of prey relative abundances and their incidence in the diet of raptors, led us to conclude that contrary to the opportunistic hunting mode suggested by others authors, these predators apparently present prey selection (on a biomass basis). This phenomenon is particularly evident in raptors of small body size.
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    ECOLOGICAL ASPECTS OF THERMOREGULATION AT HIGH-ALTITUDES - THE CASE OF ANDEAN-LIOLAEMUS LIZARDS IN NORTHERN CHILE
    (1989) MARQUET, PA; ORTIZ, JC; BOZINOVIC, F; JAKSIC, FM
    We document activity field temperatures, daily activity patterns, and extent of thermoregulation in four species of Liolaemus lizards inhabiting at high altitude (above 3500 m) in the Andes of northern Chile. These four species similar activity field temperature (Tb near 29.degree.C) despite their being distributed at different altitudinal belts. However, conspicuous differences exist between higher-altitude (L. alticolor and L. jamesi) and lower-altitude (L. islugensis and L. ornatus) lizards regarding extent of thermoregulation and activity period. Some differences in morphology, behavior, and patterns of microhabitat occupancy are also apparent among these four species and are seemingly related to the thermal environment to which they are subjected. In comparison to eight low-altitude Liolaemus species in central Chile (Tb near 35.degree.C) the four high-altitude species in northern Chile have lower activity field temperature. The latter is apparently due to the constraints imposed by the harsh Andean thermal environment, a hypothesis supported by the fact that high-altitude Liolaemus lizards under laboratory conditions demonstrated body temperatures that exceed by 5.degree.C or more, those recorded in the field.
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    ENERGETICS AND TORPOR IN THE ATACAMA DESERT-DWELLING RODENT PHYLLOTIS-DARWINI RUPESTRIS
    (1991) BOZINOVIC, F; MARQUET, PA
    The energetics of the sigmodontine rodent Phyllotis darwini rupestris, inhabiting the Pacific coastal desert of northern Chile was studied. To determine torpor states, we measured rates of oxygen consumption at different ambient temperatures, with and without food. The combination of its low basal metabolic rate coupled with its capability to enter torpor under food restriction, may allow this species to inhabit variable and unpredictable environments.
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    NATURAL-HISTORY OF MICROCAVIA-NIATA IN THE HIGH ANDEAN ZONE OF NORTHERN CHILE
    (1993) MARQUET, PA; CONTRERAS, LC; SILVA, S; TORRESMURA, JC; BOZINOVIC, F
    We document the first record of Microcavia niata in the high Andes of northern Chile near the border of Bolivia. This species is restricted to bog habitats where it principally feeds on grasses and aquatic plants. Its basal metabolic rate was 0.689 +/- 0.1 ml O2 g-1 h-1. Two colonies were studied, each possessing 15 and 17 individuals, and characterized by female-biased sex ratios. Individuals reacted aggressively against the intrusion of non-colony members and elicited alarm calls under risk of predation.