Effect of environmental parameters on squamate reptiles in an urban forest fragment in central Amazonia

Abstract

The increasing urbanization of the Amazonian biome has promoted the creation of several forest fragments surrounded by an urban matrix, but the relationship of animal assemblages to the urban environment, especially in forest fragments, is poorly known. Here we aimed to 1) determine the composition of the squamate fauna of the largest urban forest fragment from central Amazonia, in the Brazilian city of Manaus, and 2) evaluate the influence of environmental parameters on assemblage diversity. We sampled 10 standardized riparian plots through visual search in six surveys between 2008/09 and 2015, totaling 360 observer-hours. We found 15 species of lacertoids (lizards and amphisbaenians) and seven species of snakes through active search. After considering occasional encounters and search in museum collections, we recorded a total of 24 lacertoid and 22 snake species. Multiple regression models indicated that species richness and abundance of individuals increased with the distance from the edge of the fragment, while other structural parameters of the environment did not affect the assemblage. We conclude that this forest fragment 1) consists of a subset of the regional species pool, and 2) undergoes reduction of species richness and abundance of individuals from the center to the borders. This and additional urban forest fragments should be continually monitored in order to evaluate their long-term role in maintaining the tropical biodiversity.

Near infrared spectroscopy for the identification of live anurans: Towards rapid and automated identification of species in the field

“…Live anurans were captured manually between January and May 2020 in four tropical forest areas in the state of Amazonas, Brazil (Table S1 - Supplementary Material). Of these areas, three correspond to fragments of native forest in the urban center of the municipality of Manaus, mainly composed of small areas of disturbed and secondary forest, with a few open areas on the Campus of the University of Amazonas (Campus UFAM), 37,38 the Adolpho Ducke Reserve (Ducke) and forest in the Amazon Museum (MUSA). 36 Collection was also undertaken at the UFAM Experimental Farm (FEX-UFAM) which corresponds to an area of continuous dryland forest, with a mostly closed canopy and a low understory 39,40 (Figure S1 – Supplementary Material).…”

Disentangling the effects of environmental and geographic distances on lizard assemblages in Amazonian forests

“…As most species are use only a small portion of the available thermal and vegetation structure gradients, they are considered to be sensitive indicators of variation in environmental conditions (Sinervo et al, 2010). In Amazonia, lizard assemblage structure may be predicted by gradients that determine the availability of foraging, resting, refuge and thermoregulation sites, such as canopy openness and light incidence (Lobão, 2008; Moraes, 2008), leaf‐litter depth (Bittencourt, 2008; Pinto, 2006), prey availability (Lobão, 2008; Moraes, 2008), soil clay content (Pinto, 2006), elevation and slope (Lobão, 2008; Moraes, 2008), distance from waterbodies (Faria et al, 2019) and edge effects (Almeida‐Corrêa et al, 2020). Since values of those gradients are not evenly distributed over heterogeneous landscapes, they may cause spatial mosaics of habitat quality and different local subsets of species and functional traits.…”