Understory birds as indicators of forest condition in logging sites in the southern Yungas

Determining the presence or abundance of a small group of indicator species may be a more efficient alternative than sampling a community as a whole. This approach has been useful for long-term environmental monitoring schemes where species identified as indicators provide evidence of the impacts of environmental changes. Understory birds are a group sensitive to logging because they respond to changes in forest composition and structure. Our objective was to identify understory birds species that can be used as indicators of forest condition in piedmont forest of northwestern Argentina under logging. In sites under logging we conducted 202 counting points of 10 minutes duration and 50 m fixed-radius and 172 reference sites. At each site we identified bird species by visual and acoustic detection during the reproductive seasons 2015/16 and 2016/2017. To determine indicator species we applied the indicator species analysis and the dominance value analysis. We registered 2574 individuals of 37 understory birds species. Common or dominant indicator bird species in logging sites included: Thamnophilus caerulescens, Poecilotriccus plumbeiceps, Synallaxis scutata, Leptotila megalura and Cripturellus tataupa, whereas in reference sites: Sittasomus griseicapillus, Lepidocolaptes angustirostris, Cyanocorax chrysops, Casiornis rufus, Veniliornis frontalis, and Thraupis sayaca. There is a reduced group of understory birds species that may be used as indicators for the implementation of monitoring programs for changes in forest condition.