Seasonal variation and food deprivation in common vampire bats (Chiroptera: Phyllostomidae)

Abstract

The aim of this study was to investigate the effects of seasonal variation and fasting on fat reserves of the common vampire bat Desmodus rotundus. Plasma free fatty acids (FFA), along with lipid content of the liver and muscles, and fatty acids from the carcass were obtained from bats fed bovine blood and from whom food was subsequently withheld for 24 and 48 h. Animals were caught during both dry and rainy seasons. In general, fat tissue stores were not significantly influenced by seasonal variation. Lipid content of liver, muscles, and carcass decreased during some food deprivation periods, although the concomitant increase expected in plasma FFA was not observed. Lipid metabolism is hypothesized as being continued by the tissues themselves. In addition, free access to food sources (e.g., domestic livestock) throughout the year is believed to contribute to the low seasonal variations in fat reserves observed in the common vampire bat.

Seasonal variation of energy reserves and reproduction in neotropical free-tailed bats Molossus molossus (Chiroptera: Molossidae)

“…The data obtained here seem to indicate that lipid reserves of male M. molossus remained unaltered in all seasons, except for the adiposity index. Common vampire bats (Desmodus rotundus) captured in central Brazilian areas also showed no significant differences in lipid reserves between dry and rainy seasons (Freitas et al, 2006). Nevertheless, unlike the observed for insectivorous species (Srivastava and Krishna, 2008), the vampire's food supply (bovine blood) does not vary seasonally.…”

“…According to Srivastava and Krishna (2008), this is especially significant for bats from temperate regions, since their reproduction is frequently synchronized with food availability in the environment. For neotropical bats, the influence of seasonality on energy reserve allocation and reproductive events appears to vary between species, depending on their food habits and area of occurrence (Altringham, 1998;Neuwriler, 2000;Freitas et al, 2006).…”

Energy metabolism and fasting in male and female insectivorous bats Molossus molossus (Chiroptera: Molossidae)

“…This unique mammal consumes his blood meal every night, but shows severe hypoglycemia when submitted to fasting, not being able to keep plasma glucose concentrations compatible to life for after only 12 hours of fasting, which characterises the species, unlike the others also fed on protein diets, as highly susceptible to fasting. This pattern seem to be shaped mainly due to its limited ability to store energy fuels when food is available and/or mobilise existing stores when food is scarce (Freitas et al, 2003(Freitas et al, , 2005(Freitas et al, , 2006.…”

Energy reserves of Artibeus lituratus (Chiroptera: Phyllostomidae) in two areas with different degrees of conservation in Minas Gerais, Brazil

“…The storage and mobilisation of these reserves may vary, according to food availability in the environment (Powers et al, 2000;Douglas, 2002). It has been shown that the storage of body energy reserves is essential for the survival and maintenance of several species of bat populations, as the mobilisation of these reserves provides the necessary energy for events associated with reproduction and adaptation to periods of food shortage (seasonality and fasting) (Freitas et al, 2006;Pinheiro et al, 2006;Wang et al, 2008;Freitas et al, 2010).…”