Mammal diversity among vertical strata and the evaluation of a survey technique in a central Amazonian forest

Abstract

Mammal groups have a vast variety of habitats, which include aquatic, aerial, arboreal, and terrestrial. For terrestrial habitats, camera traps are used as a common technique to record mammals and other vertebrates and have been recently utilized to observe arboreal animals as well. Here, we compare the difference in mammal diversity between floor and canopy strata and evaluate the use of camera trapping in a lowland forest in central Amazon. We installed nine paired camera traps, one in the canopy stratum and other in the floor stratum, in the Alto Cuieiras Biological Reserve (Brazilian Amazon). With a sampling effort of 720 camera-days, we recorded 30 mammal species: nine in canopy strata, 14 in floor strata, and seven in scansorial strata (sharing both strata). On the forest floor, the species with the greatest abundance was Myoprocta acouchy; in the canopy, Isothrix paguros had the greatest abundance; and among the scansorial species, Proechymis sp. was the most abundant. Our results show the differences in mammal diversity between floor and canopy strata; canopy strata contained more small and frugivorous mammals. Although we obtained a relatively low sampling effort with the camera-trap method compared with other studies utilizing different techniques, our results were especially similar to those of previous studies that worked with canopy and floor strata. Thus, camera trap can be very effective for recording short periods of time, and this method is less physically exhaustive and expensive for researchers to study vertical strata.

Massive Bird Nest Losses: A Neglected Threat for Passerine Birds in Atlantic Forest Fragments from the Pernambuco Endemism Center

“…Because species richness (alpha diversity) is a proxy of sampling effort, uncovering all of the species in a target community can be a challenging task, especially in megadiverse habitats such as the Atlantic Forest [41]. Among the innumerous methods developed to estimate expected species richness based on collected data, the non-parametric estimators, e.g., Chao2, ICE, Jackknife1, and Jackknife2, have been widely used in studies involving camera trap data [42][43][44]. Here, we chose a Jackknife estimator because this class of estimator performed better than others in two comparative studies that used camera traps for faunal surveys in tropical forests [42,44].…”

“…Although in some regular camera trap surveys the cameras can be arranged in the field across pre-defined grids or transects [42,48,49], in many other works, the cameras are distributed randomly across sites with animal traces, respecting only a minimum distance interval [43,44,50], and our study involving widespread nests may not differ from the latter. Although each camera-day can be treated as a sampling unit for species richness estimations, here, for graphical purposes, we partitioned our dataset into 50 camera-days subsets that were used as sampling unities for Jackknife2 calculations (see also [49]).…”

Composition of terrestrial mammal assemblages and their habitat use in unflooded and flooded blackwater forests in the Central Amazon

“…For subsistence and cash income, the residents are generally engaged in agricultural and extractive activities and ecotourism, which is of great importance for the region. Despite the presence of the communities, the forest retains a full complement system of vertebrate species ( Arévalo-Sandi et al, 2021 ) and remains virtually undisturbed. It includes a unique landscape mosaic that contains large expanses of terra firme (~86%) and igapó forest (~3%), the latter being seasonally flooded by the Negro River.…”