A estrutura da paisagem como moduladora da avifauna dos banhados da região campestre de campos com barba-de-bode

Abstract

The fragmentation and degradation of natural environments cause serious damage to avifauna. In the marshes, these damages to the avifauna may be caused by high water drainage, the intensity of livestock access, and the transformation of native vegetation into crops for grain production. Understanding how these changes affect bird diversity may be critical to its conservation. The effects of environmental degradation on the community of birds can vary according to the levels of degradation. Thus, we search to investigate, through multivariate modeling, the effects of the main landscape variables: size of the marshes, surrounding landscape matrix, access of livestock and presence of water blade on the abundance and the community of birds associated with marshes localized into a pasture with Aristida spp grassland. A survey was carried out in 24 sample units, in the spring season of 2017, using the listening points method to sample the birds. Each marsh had its area measured, and its main landscape characteristics were obtained by the visual observations and the use and Google Earth Pro satellite imagery. In the qualitative survey we identified 126 bird species identified belonging to 20 orders and 41 families. Endangered species and with lacking data such as Xanthopsar flavus, Sporophila pileata, Gubernetes yetapa, Sporophila collaris and Cairina moschata were sighted, it was also recorded for the first time the Sporophila beltoni, an endemic species from Brazil and hardly found in the Rio Grande do Sul State was observed for the first time in the Missions region (northwest of Rio Grande do Sul State). In general, the greater the marshes, the more preserved the surrounding matrix (native grassland formations), the presence of water depths and the absence of cattle access in the marshes are the conditions in which there is greater bird abundance and with the presence of a greater number of wild birds. However, the presence marshes of more preserved environment matrix may be minimizing the effects of environmental degradation, and these should be considered in the management of farms.