Mass Extinction and the Disappearance of Unknown Mammal Species: Scenario and Perspectives of a Biodiversity Hotspot’s Hotspot

Abstract

We aimed to determine the conservation status of medium- and large-sized mammals and evaluate the impact of 500 years of forest fragmentation on this group of animals in the Pernambuco Endemism Center, in the biogeographical zone of the Atlantic forest north of the São Francisco River in northeastern Brazil. Line transect surveys were performed in 21 forest fragments, resulting in a checklist of the mammals of the entire Pernambuco Endemism Center area. We ran a generalized linear model (Factorial ANCOVA) to analyze to what extent the vegetation type, fragment area, isolation, sampling effort (as total kilometers walked), or higher-order interactions predicted (a) richness and (b) sighting rates. To determine if the distribution of the species within the forest fragments exhibited a nested pattern, we used the NODF metric. Subsequently, we performed a Binomial Logistic Regression to predict the probability of encountering each species according to fragment size. Out of 38 medium- and large-sized mammal species formerly occurring in the study area, only 53.8% (n = 21) were sighted. No fragment hosted the entire remaining mammal community, and only four species (19%) occurred in very small fragments (73.3% of the remaining forest fragments, with a mean size of 2.8 ha). The mammalian community was highly simplified, with all large mammals being regionally extinct. Neither the species richness nor sighting rate was controlled by the vegetation type, the area of the forest fragments, isolation or any higher-order interaction. Although a highly significant nested subset pattern was detected, it was not related to the ranking of the area of forest fragments or isolation. The probability of the occurrence of a mammal species in a given forest patch varied unpredictably, and the probability of detecting larger species was even observed to decrease with increasing patch size. In an ongoing process of mass extinction, half of the studied mammals have gone extinct. The remaining medium-sized mammal community is highly simplified and homogenized. The persistence of these species in a forest patch is determined by their ability to adapt to a novel simplified diet, the efficient use of the surrounding matrix without being engulfed by the sink effect, and escaping hunting. Our results suggest that the 21st century medium-sized mammalian fauna of this region will comprise only four species unless strict conservation measures are implemented immediately and every forest fragment is effectively protected.

Range extension and first record of Coendou speratus Mendes Pontes et al., 2013 (Rodentia, Erethizontidae) from a cloud forest enclave in northeastern Brazil

“…Coendou speratus has already been classified as endangered with extinction by the Brazilian authorities (MMA 2014) due to its very restricted distribution and highly fragmented and declining populations in the Atlantic Forest of the Pernambuco Center of Endemism, although the species has yet to be evaluated by the International Union for Conservation of Nature (Mendes Pontes et al 2016). In this paper, we provide the first record of C. speratus in a cloud forest enclave within the Caatinga dry forest biome, and extend the known distribution of the species 167 km west of its type locality.…”

First records of Ocelot Leopardus pardalis (Linnaeus, 1758) (Carnivora: Felidae) from Rio Grande do Norte, northeastern Brazil

“…In the part of the Atlantic Forest remnant to the north of the San Francisco River, reports of Ocelot are rare (Figure 1), which is possibly due to the scarcity of surveys of medium-sized and large mammals (Feijó & Langguth 2013;Feijó et al 2016), as well as the low quality of most northern Atlantic Forest remnants to sustain viable populations of mammals such as Ocelot (Silva Jr. & Mendes Pontes 2008;Mendes Pontes et al 2016).…”

“…Pressure from hunting and from being killed by motor vehicles threatens the species in this area (Oliveira et al 2013;Paviolo et al 2016;Alves et al 2016). The hunting of felids in northeastern Brazil is mainly related to cattle and poultry predation (Alves et al 2016), which is associated with an increased degree of degradation leading to the near-extinction of large-sized species such as the Jaguar, Panthera onca (De Paula et al 2012;Mendes-Pontes et al 2016), and endangered small felids such as the Northern Tiger Cat, Leopardus tigrinus (Marinho 2015).…”

“…The extensive loss and fragmentation of habitats in the Atlantic Forest to the north of the São Francisco River leaves wild animals more exposed to secondary threats (Galetti et al 2009;Mendes Pontes et al 2016). This context of degradation and intensive human occupation in the remnants of the northern Atlantic Forest (Ribeiro et al 2009) represents a critical scenario for the occurrence of medium-sized and large mammals, with a clear trend towards simplification of the mammal community and local extinction of large mammals (Silva Jr. & Mendes Pontes 2008;Mendes Pontes et al 2016).…”

“…This context of degradation and intensive human occupation in the remnants of the northern Atlantic Forest (Ribeiro et al 2009) represents a critical scenario for the occurrence of medium-sized and large mammals, with a clear trend towards simplification of the mammal community and local extinction of large mammals (Silva Jr. & Mendes Pontes 2008;Mendes Pontes et al 2016).…”