Bat fat: body composition analysis by total body electrical conductivity in northern long-eared bats

Bat fat: body composition analysis by total body electrical conductivity in northern long-eared bats

The ability to assess the 'condition' of small mammals in a non-invasive and non-stressful manner is important for understanding their natural history. More specifically, body condition is measured to determine if an animal is in positive or negative energy balance. Stored energy is a component of a total energy budget. One recent technology for assessing body condition is Total Body Electrical Conductivity (TOBEC). A TOBEC index should correlate with components of more traditional body composition analyses, such as body fat and lean mass. As part of our efforts to understand bat hibernation energetics, we made TOBEC measurements (EM-SCAN Model 3044) of northern long-eared bats (Myotis septentrionalis) to determine its accuracy and usefulness on animals of this size (6-8 g). The bats were then euthanized, dried to a constant mass, subjected to a Soxhlet fat extraction process, and re-dried to constant mass. Standard body composition parameters were calculated. A preliminary analysis of these data indicate no significant correlations between the raw TOBEC measurements and carcass lean wet mass, fat mass, or percent body fat. These animals may be too small for use of TOBEC in assessing their energy storage, although additional calculations and a larger sample size may prove useful.

This was an oral presentation only. Full paper not available.