An estimation of road mortality of birds in Nahuel Huapi National Park, northwestern Argentine Patagonia

Abstract

A 27 km-section of the National Route 258 which goes from San Carlos de Bariloche to El Bolsón, in Río Negro Province, northwestern Argentine Patagonia, was surveyed four times a day during three years. The section considered lies in Nahuel Huapi National Park. All birds found dead along this road were collected. When possible, each individual was identified as juvenile or adult. Based on these data, the avian mortality rate was estimated for all species and for the most frequently found species. Considering the total number of kilometres in the park, a preliminary estimation of the annual toll of birds killed on roads was performed. Twenty-nine bird species (belonging to 13 families) were found, and Strix rufipes predominated with 10 individuals found dead. The annual mortality rate was 0.54 ± 0.19 birds per kilometre per year; the rate for Strix rufipes was 0.19 ± 0.08. The determination of factors influencing the relatively high road mortality of Strix rufipes (considered a scarce species in the park), would be of importance for its conservation at local and regional scales.