BIRD MIGRANT ASSEMBLAGES IN URBAN AND RURAL AREAS OF CENTRAL ARGENTINA: A REGIONAL-SCALE COMPARISON

Abstract

Migrant birds are negatively impacted by urbanization. However, most of the studies about urbanization effects on migrant birds were conducted in the Northern Hemisphere, and studies performed in South America are scarce. This study compares the migrant bird assemblages of urban parks and rural areas of central Argentina. Summer migrant birds were surveyed by standardized point counts in urban parks of six cities. In contrast, rural migrant assemblages were assessed through species lists of the citizen science project eBird in six paired sites. Sample coverage was similar between urban parks and rural areas (0.89 and 0.92, respecti-vely). Migrant species richness was higher in rural than in urban parks. Migrant species composition changed between habitats, and species turnover was the dominant aspect of species dissimilarity. Urban parks had more occurrences of the Glittering-bellied Emerald (Chlorostilbon lucidus) and the Tropical Kingbird (Tyrannus melan-cholicus), whereas rural sites had more occurrences of the Vermillion Flycatcher (Pyrocephalus rubinus) and the Double-collared Seedeater (Sporophila caerulescens). Grasslands present in rural areas may favor the presence of the Vermillion Flycatcher and the Double-collared Seedeater. Therefore, cities are related to significant changes in the migrant bird communities.