GRASSLAND HABITAT VARIABLES ASSOCIATED TO THE DENSITY OF GRANIVORE BIRDS IN MALPAÍS, DURANGO, MEXICO

Abstract

Grassland birds constitute the group that has decreased its populations most in North America. Various studies suggest that there are key variables of this habitat that limit their abundance and distribution. In January 2013, bird censuses were carried out through a characterization of the vegetation structure and the availability of seeds in the soil were estimated. Through generalized linear models the variables that predict density of seven grassland bird species were determined. All the variables were included in at least one model of one of these species. The seed biomass was an important predicting variable individually or in interaction with other variables, highlighting the case of Spizella pallida and Ammodramus savannarum. For the first time the food availability is included as a variable in studies of habitat association in the hibernation area of these birds in México. This information can be used in the strategies of conservation and management of these species and their habitats.