Diversity and activity patterns of medium and large mammals in La Encrucijada Biosphere Reserve, Chiapas, Mexico. In Mexico, wetlands occupy an important portion of the country, among them, mangroves are particularly diverse. La Encrucijada Biosphere Reserve (ENBIRE) is a coastal ecosystem of mangrove located along the Pacific Coastal Plain in the Southwestern portion of Chiapas state. The ENBIRE mangroves are among the most important of the American Pacific Coast, highlighting the role they play in the maintenance of the community of mammals on the coast of the state. There are few studies in Mexico related to the mammals associated with these ecosystems, our aim was to estimate the diversity and activity patterns of medium and large mammals in the ENBIRE. Sampling was conducted from August 2015 to August 2016 using camera traps. We obteined 1 851 independent photographs records, with a total sampling effort of 5 400 trap-days. Nineteen species of mammals were registered belonging to 15 families and seven orders, and five species were new records to the area. Six species present are listed, two as endangered and four as threatened. Interpolation and extrapolation analyzes showed an asymptotic trend in the curves for the rainy and dry seasons. The coverage of the sample for both seasons was 99.9 % and 99.8 %, respectively, indicating that both cases were a representative sample. According to the relative abundance index obtained, the most abundant species were Procyon lotor (IAR = 4.35), Nasua narica (IAR = 3.91), Philander opossum (IAR = 2.04), Cuniculus paca (IAR = 1.89), Didelphis marsupialis (IAR = 1.67) and Dasypus novemcinctus (IAR = 1.02). In terms of patterns of activity C. paca, P. opossum, D. marsupialis and D. novemcinctus were primarily nocturnal; P. lotor showed a tendency towards nocturnal habits but was also recorded during the day; N. narica was mainly diurnal. This information can be useful to the creation of management programs and the conservation of medium and large mammals in the ENBIRE, especially for species at risk. Rev. Biol. Trop. 66(2): 634-646. Epub 2018 June 01.

Keywords: camera-traps, species richness, wetlands, wild mammal ecology.