Influência de mudanças meteorológicas na abundância de aves e mamíferos de dossel no Jardim Botânico - UFJF

Abstract

The canopy, the upper layer of tropical forests formed by the treetops, is one of the most biodiversity-rich habitats. Due to its specific microclimatic conditions, small meteorological variations, such as in humidity and temperature, can impact the presence and activity patterns of the species that use it. However, knowledge about the vertebrates that inhabit the canopy is scarce, as it is a difficult-to-access environment for researchers. In this context, thermal drones emerge as an important tool for monitoring fauna in these restricted areas. The UFJF Botanical Garden is a fragment of Atlantic Forest in an urban environment, where little is known about its canopy fauna. Aiming to estimate the richness and absolute abundance of canopy-dwelling birds and mammals in the UFJF Botanical Garden, as well as the meteorological factors influencing their occurrence monitoring was carried out using a DJI-Mavic 3 Thermal Enterprise drone in the morning during January and February, totaling 42 flight hours. The influence of meteorological variables was analyzed through generalized linear models (GLMs) with negative binomial distribution. A total of 36 vertebrate taxa were recorded in the canopy. Birds represented the group with the highest number of species and individuals, with the most frequently recorded species being Penelope obscura (n = 13; 36.1%), Dacnis cayana (12; 33.3%), and Pionus maximiliani (10; 27.8%). Three species of mammals were recorded: Alouatta guariba (8; 22.2%), Bradypus variegatus (4; 11.1%), and Eira barbara (1; 2.8%). A significantly higher number of individuals using the canopy was recorded on more humid mornings (p = 0.00096), as well as on mornings following cooler days (p = 0.0022). The species present in the canopy demonstrate high sensitivity even to small environmental variations in humidity and temperature. This may indicate that meteorological changes can alter the behavior, activity patterns, and distribution of treetop-dwelling animals, leading to changes in the ecological dynamics of this habitat, a significant concern, given that such local changes are expected to intensify under ongoing climate change.