Assessing the effects of landscape attributes in medium and large terrestrial mammal richness inside a tropical rainforest biosphere reserve

The landscape's structure significantly impacts how communities assemble due to the environment filtering and the limitation of dispersal processes. Human activities can enhance or alter these factors, resulting in changing environments and isolated animal populations. In studying this, we used 39 camera trap stations during 102 continuous days in preserved and disturbed areas to assess medium and large terrestrial mammals in the Selva El Ocote Biosphere Reserve in Chiapas, Mexico (REBISO). We identified various groups of mammals and the factors influencing their presence and distribution through VIF, Clustering, RDA, NDMS, ANOSIM multivariate, and niche decomposition (OMI) analyses. The redundancy analysis (RDA) indicated that the most significant variables were altitude, distance to main roads and settlements, and forest cover. The optimal multivariate indicator (OMI) analysis accounted for 88.75% of the variability in niche structure. It revealed that Puma concolor exhibited the highest level of specialization (marginality = 2.96), while Nasua narica displayed the most generalist behavior (marginality = 0.26). Natural elements and human impact played a crucial role in the species' distribution, resulting in patterns in two distinct conditions: one characterized by preserved natural environments and the other affected by significant human impact. Notably, 63% of the species were common in both regions. For instance, Cuniculus paca positively correlated with distance to main roads and altitude, whereas Leopardus pardalis negatively responded to proximity to settlements. This study emphasizes the importance of maintaining habitat connectivity to preserve terrestrial mammal species.

Didelphis spp. opossums and their parasites in the Americas: A One Health perspective

Medium sized opossums (Didelphis spp.) are among the most fascinating mammals of the Americas, playing important ecological roles (e.g., dispersal of seeds and control of insect populations) in the environment they inhabit. Nevertheless, as synanthropic animals, they are well adapted to human dwellings, occupying shelters within the cities, peripheral areas, and rural settings. These marsupials can harbor numerous pathogens, which may affect people, pets, and livestock. Among those, some protozoa (e.g., Leishmania infantum, Trypanosoma cruzi, Toxoplasma gondii), helminths (e.g., Ancylostoma caninum, Trichinella spiralis, Alaria marcianae, Paragonimus spp.) and arthropods (e.g., ticks, fleas) present substantial public health and veterinary importance, due to their capacity to cause disease in humans, domestic animals, and wildlife. Here, we reviewed the role played by opossums on the spreading of zoonotic parasites, vectors, and vector-borne pathogens, highlighting the risks of pathogens transmission due to the direct and indirect interaction of humans and domestic animals with Didelphis spp. in the Americas.