Relación entre la cobertura del suelo y atributos de la vegetación invernal con Ammodramus bairdii, Audubon 1844, en el noroeste México

Abstract

Baird's Sparrow (Ammodramus bairdii) is a migratory grassland bird, whose populations are diminishing, situation aggravating because of the little information available about its wintering habitat requirements in México. The objective of the present study was the assessment of the relationship between soil cover and attributes of winter vegetation with the abundance of Baird's sparrows in the region of Cuchillas de la Zarca in the northwest of México. Therefore, monitoring of birds, soil cover, and vegetation was carried out during the winters 2009 and 2010, using linear transects. The characteristics of the vegetation, where this sparrow was found, did not show significant variability among the monitored quadrants; thus, their values could indicate the wintering habitat for this species in the study area. Spearman rank correlation (rs) was positive for the variables grass height (rs=0.56; p=0.04) and herbage cover (rs=0.60; p=0.02). Ammodramus bairdii prefers sites with tall grass and up to 11 % herbage cover. This study provides valuable information about general characteristics of the winter habitat for this species in México and, furthermore, that more information is required for the conservation of this bird species in its distribution area.