Ecología de forrajeo del fara Didelphis pernigra (Didelphidae, Didelphimorphia) en un área suburbana del norte de Bogotá, Colombia
Suárez Cáceres, Gina Patricia | 2013
I applied optimal patch use theory to examine the foraging of the white-eared opossum Didelphis pernigra in the north Bogotá, an area that mixes highly-modified environments and natural remnants. Theory predicts that a forager will use a feeding patch as long as benefits are higher than energetic, perceived risk of predation, and missed opportunity costs. I examined whether the opossum’s foraging was affected by feeders height above the ground, food quality and quantity, and spatial heterogeneity. Feeder height affected the opossum’s foraging; they preferred foraging at 2 m than at 0.5 m, probably to reduce the risk of being predated for example by domestic dogs. When offered food with higher sugar concentration but fewer amount than food with higher amount but lower sugar concentration, opossum preferred forraging on those with higher concentration at 0.5 m, but there were no differences between the two food types at 2 m. Also, opossums were affected by spatial heterogeneity and preferred foraging along areas with metallic fences compared to areas with continuous tree canopy, probably because fences facilitated mobilization, although this effect was more evident in one of the two months of study. In areas where cables that allowed the opossums’ movements were added, the value of food patches increased. Thus, even though opossums need resources from natural environments, some modifications made by humans may benefit them, such as those reducing predation risk and favoring mobilization.