The distribution of neotropical migrant birds wintering in the El Cielo biosphere reserve, Tamaulipas, Mexico

We documented the distribution of Neotropical migrant species wintering in four habitats in the Sierra Madre Oriental mountains in northeastern Mexico. We used point-count surveys and mist nets to determine the presence and relative abundance of migrant species in tropical semi-deciduous forest (300 m elevation), cloud forest (1,100 m elevation), humid oak-pine forest (1,200 m elevation), and dry pine-oak forest (1,800 m elevation) in the El Cielo Biosphere Reserve in Tamaulipas, Mexico. Thirty-two species of migrants were observed during the winters of 1993-1995; migrant species represented from 17% to 33% of the species detected in point counts and captured in mist nets in each habitat. Nearly half of the migrant species in El Cielo were habitat specialists; other species were found in a variety of habitats across their wintering ranges. Ruby-crowned Kinglet (Regulus calendula), Wilson's Warbler (Wilsonia pusilla), Blue-gray Gnatcatcher (Polioptila caerulea), and Hermit Thrush (Catharus guttatus) were the most frequently detected migrant species in El Cielo. Northern Mexico is an important wintering area for a diverse group of migrant species. Habitats at higher elevations with temperate-like forests and at lower elevations with tropical forests had the greatest species richness and supported the highest abundance of migrant species.