Banca de DEFESA: PAULO FERNANDES DA COSTA NETO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : PAULO FERNANDES DA COSTA NETO
DATA : 28/02/2018
HORA: 14:00
LOCAL: DIDATICO I – DEPARTAMENTO DE ECOLOGIA
TÍTULO:

Patterns of habitat use and co-occurrence of the Herpsilochmus genus in a forest remnant in the northern of Atlantic Forest distribution

PALAVRAS-CHAVES:

environment heterogeneity, niche overlap, syntopic species, imperfect detection, competitive exclusion.

PÁGINAS: 30
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

The bird distribution in the environment is modulated by habitat complexity and seasonal changes in resource availability, characteristics whose understanding is essential for accurate inferences about how species use the habitat. In addition, interspecific interactions also affect the distribution and the way in which the species use the habitat and may be an important factor to understand the coexistence, especially between congeneric species. Here, we used occupancy models for one and two species to investigate how vegetation structure and interspecific interactions affect patterns of habitat use and co-occurrence in three sympatric species of the genus Herpsilochmus (H. atricapillus, H. pectoralis and H. rufimarginatus). The study was carried out in a forest remnant at the northern portion of the Atlantic Forest distribution (RPPN Mata Estrela), northeastern Brazil. For this, we performed point-count surveys in 80 sample units, in the dry and rainy season, and collected variables related to the vegetation structure. From this we created sets of occupancy and co-occurrence models and selected the best ranked for each species and combination of species. As results of occupancy models we verified that the species H. atricapillus and H. pectoralis had high occupancy rates (Ѱ > 0.89 ± 0.07), whereas H. rufimarginatus had moderate, which was higher in forest areas (Ѱ = 0.47 ± 0.34 - 0.68 ± 0.15). The density of trees was the most important variable in the occupancy of the species, but with positive effect on H. pectoralis and negative effect on H. rufimarginatus. Although the best model for H. atricapillus also includes tree density, the effect of the variable seems uncertain. The detection probabilities ranged from low (p = 0.19 ± 0.03) to moderate (p = 0.59 ± 0.05) between species. The co-occurrence models brought evidence that H. pectoralis is related with a decrease in H. rufimarginatus occupancy, which was stronger in restinga areas, while the detection probabilities were independent for both. In the other side, the presence of H. atricapillus positively affected the occupancy of H. rufimarginatus, mostly, in restinga areas. Finally, the occupancy of H. pectoralis was independent of H. atricapillus, but the detection was negatively affected by the presence of H. atricapillus. Our results indicate that the tree density is the most important factor in the habitat use by the species studied here. In addition, the occupancy pattern of H. pectoralis and H. rufimarginatus could be influenced by competitive interactions, which associated with different micro-habitat preferences may be modulating the coexistence among these species. In contrast, H. rufimarginatus may be benefiting from the presence of H. atricapillus by following mixed flocks, either by increasing foraging efficiency or by protecting themselves against predators, but more studies are needed to understand this pattern of aggregation among species.

MEMBROS DA BANCA:
Interno - 1718346 - EDUARDO MARTINS VENTICINQUE
Presidente - 1439088 - MAURO PICHORIM
Externo à Instituição - RODRIGO LIMA MASSARA - UFMG