Body Condition in Birds in Two Landscapes of the Upper Magdalena Valley, Colombia

The body condition (BC) is the sum of factors such as the state of energy reserves, the degree of health and the physiological wear of an individual. Despite its importance and the existence of a wide range of methodologies to measure it, in the Neotropic there are few works that value this variable in contrast to environmental conditions. The aim of this study was to analyze the BC during the years 2012-2013 of 13 bird species in two intervened landscapes in the tropical dry forest, located in the north of Tolima and the southwest of Huila in the region of the upper Magdalena Valley (UVM). The BC of species was assessed using the scaled mass index (SMI), using morphometric data such as wing chord, tarsal length and body mass. Significant differences were found in the SMI between landscapes and climatic seasons in the species Formicivora grisea, Saltator striatipectus, Sporophila schistacea and Basileuterus rufifrons. It was concluded that environmental variables evaluated affect the BC of some species but not the avifauna in general, mainly due to the effect of these variables on the availability of resources, the necessary energy spending to obtain them and the sensitivity of species to environmental changes.