Effect of artificial perches and the avifauna involved in the ecological restoration of a mined area in the south of Brazil

Abstract

The present study analyzed the effect of artificial perches in the supply of vegetal propagules and in the avifauna attraction in degraded area due to mining, in Rio Grande do Sul, Southern Brazil. The seed rain was sampled monthly from December, 2014 to April, 2015, in four collector tables arranged under artificial perches and in four control collector tables (without perches). We compared the seeds number by the Mann-Whitney U test (5% probability level) and used the Spearman correlation to calculate the association degree among the visitor birds on perches and the seeds number sampled in the collectors under perches. The avifauna monitoring was performed during the same period by fixed point method, totalizing 40 hours of sampled effort. The treatments differed statistically, with registration of 1588 seeds in the tables under perches and 237 seeds in the tables without perches. The sampling of seed rain in the perches followed the pattern of avifauna visitation, presenting high value to coefficient of association degree (0.975). We observed nine species of birds in the study area, and the Tyrannidae family was predominant. The species observed visiting the artificial perches were Knipolegus lophotes and Tyrannus melancholicus, both from Tyrannidae family. The number of sampled seeds demonstrates that artificial perches were efficient to return seed rain in the mined areas. The Tyrannidae family demonstrates to be the most effective group of birds to dispersion of seeds in the local of study.