Washington, September 9 : Spanish researchers have discovered that bearded vultures choose bones containing the highest fat content and discard less energy-dense ones, when it comes to their food or feeding their young.
Research leader Antoni Margalida, from the Bearded Vulture Study and Protection Group in El Pont de Suert, chose to study bearded vultures living in the mountains of the Pyrenees in Spain.
Since the environment there is very harsh, the author believes that the bearded vulture's high energy requirement leads it to choose smaller, more energy dense bones.
He says that this way the vulture ensures that the energy consumed is greater than the energy expended in obtaining the food.
Besides energy density, the research also focused on whether larger bones were discounted as being too difficult to transport and swallow.
I was found that bones not selected by the bearded vultures had a lower content of oleic acid than the selected ones, suggesting that nutritive content had a greater impact on choice than bone size.
Margalida also found that the bearded vultures selected the bones with the highest fat content to transport to their nests.
"The close association between bones selected and their high fat value implies an optimization of foraging time and of the increased energy gained from the food," he said.
He further said that the new findings held significance for the conservation of both the wild and captive populations of the endangered species.
He suggests that efforts to facilitate geographic expansion and breeding of the vultures use the most nutritive bones in feeding programs.
He also highlights the fact that tibias, tarsals, and extremities are the vulture's favourites.
The study has been published in the journal Behavioral Ecology and Sociobiology.