In tropical dry environments rainfall periodicity may afect demographic parameters, resulting in luctuations in bird abundance. We used capture-recapture data for the Grey Pileated Finch from a Neotropical dry forest to evaluate the hypothesis that intra-and inter-annual survival, individuals entrance and population abundance, are related to local rainfall. Sampling occurred across 3 years, with individuals captured, tagged and evaluated for age and presence of brood patch every 14 days. Using the POPAN formulation, we generated demographic models to evaluate study population temporal dynamics. Best-it models indicated a low apparent annual survival in the irst year (16%) compared to other years (between 47 and 62%), with this low value associated with an extreme drought. The abundance of juveniles at each capture occasion was signiicantly dependent on the accumulated precipitation in the previous 14 days, and the juvenile covariate was a strong predictor of the intra-annual entrance probability (natality). Individuals entrance during the reproductive period corresponded to 53, 52 and 75% of total ingress for each year, respectively. The trend in sampled population size indicated positive exponential growth (N initial = 50, N last = 600), with intra-annual luctuations becoming progressively more intense. Low survival was relevant during population decline at study onset, while at study end intense Individuals entrance promoted rapid population growth. Thus, the indirect efects of rainfall and the combined efect of two demographic rates operated synergistically on the immediate population abundance of Grey Pileated Finch, an abundant bird in a Neotropical dry forest.

Abstract:Seasonal fluctuations in bird abundance are expected in semi-arid environments, but estimates may be biased if detectability is not considered. In a tropical dry forest in north-eastern Brazil, we evaluated whether bird abundance is highly seasonal, and associated with time-specific variability in detectability. We mark-recaptured birds with mist nets over three field visits (3487 records from 75 species), and used closed-capture models to estimate detectability and abundance in birds divided into three groups (all, residents, insectivores). In the two dry periods, the best models resulted in capture estimates at least three times larger than recapture, and both estimates were twice that of when rains occurred on the day preceding sampling. Abundance varied between dry and wet periods from 4.0 (from 115 ± 34 to 479 ± 144) to 13 times (183 ± 8 to 2463 ± 351). Estimates were 1.5–3.2 times greater in the dry period when behavioural responses of birds were excluded from capture-recapture models. Meanwhile, in the wet period the relative abundance was between 33–76% smaller than best-fit models estimated. This study found variation in avian abundance greater than that observed in other Neotropical dry forests, and indicates that biases may be common when not including detectability.

Phyllopezus lutzae (Loveridge, 1941) is a bromelicolous lizard species that inhabits the Atlantic Forest in northeastern Brazil. In this work we report the first records of this species for Paraíba state, Brazil. The records extend the distribution of the species 47 km north, helping to fill a gap in its distribution in northeastern Brazil

No abstract