Ecological Relationships of Meso-Scale Distribution in 25 Neotropical Vertebrate Species

Abstract

Vertebrates are a vital ecological component of Amazon forest biodiversity. Although vertebrates are a functionally important part of various ecosystem services they continue to be threatened by anthropogenic impacts throughout the Amazon. Here we use a standardized, regularly spaced arrangement of camera traps within 25km2 to provide a baseline assessment of vertebrate species diversity in a sustainable use protected area in the eastern Brazilian Amazon. We examined seasonal differences in the per species encounter rates (number of photos per camera trap and number of cameras with photos). Generalized linear models (GLMs) were then used to examine the influence of five variables (altitude, canopy cover, basal area, distance to nearest river and distance to nearest large river) on the number of photos per species and on functional groups. GLMs were also used to examine the relationships between large predators [Jaguar (Panthera onca) and Puma (Puma concolor)] and their prey. A total of 649 independent photos of 25 species were obtained from 1,800 camera trap days (900 each during wet and dry seasons). Only ungulates and rodents showed significant seasonal differences in the number of photos per camera. The number of photos differed between seasons for only three species (Mazama americana, Dasyprocta leporina and Myoprocta acouchy) all of which were photographed more (3 to 10 fold increase) during the wet season. Mazama americana was the only species where a significant difference was found in occupancy, with more photos in more cameras during the wet season. For most groups and species variation in the number of photos per camera was only explained weakly by the GLMs (deviance explained ranging from 10.3 to 54.4%). Terrestrial birds (Crax alector, Psophia crepitans and Tinamus major) and rodents (Cuniculus paca, Dasyprocta leporina and M. acouchy) were the notable exceptions, with our GLMs significantly explaining variation in the distribution of all species (deviance explained ranging from 21.0 to 54.5%). The group and species GLMs showed some novel ecological information from this relatively pristine area. We found no association between large cats and their potential prey. We also found that rodent and bird species were more often recorded closer to streams. As hunters gain access via rivers this finding suggests that there is currently little anthropogenic impact on the species. Our findings provide a standardized baseline for comparison with other sites and with which planned management and extractive activities can be evaluated.

Terrestrial mammal assemblages in protected and human impacted areas in Northern Brazilian Amazonia

“…In this study Carnivora was the most speciose order, followed by Artiodactyla, in both PAs and IAs, suggesting that the structure of the mammalian community is preserved, although some of the species are generalist and matrix/fragmented tolerant species, such as Eira barbara. Studies in the Neotropics have shown that Carnivora is the most speciose order of large terrestrial mammals in protected areas, followed by Artiodactyla (Tobler et al 2008, Munari et al 2011, Springer et al 2012, Santos and Oliveira 2012, Ahumada et al 2013, Burton et al 2015, Michalski et al 2015, whereas in protected areas that are surrounded by human disturbances, Carnivora was followed by Rodentia and Xenarthra, which could represent an intermediate conservation status (Pickles et al 2011, Carvalho et al 2014, Lizcano et al 2016, or Rodentia could even be the most speciose order (Michalski et al 2015). In impacted areas, however, the most speciose order seems to be Xenarthra, followed by Rodentia Peres 2007, Botelho et al 2012).…”

“…Different patterns, however, may be found in highly impacted areas, in which most medium-sized and large mammals are extirpated or driven to such low numbers that the most abundant species becomes the smallerbodied rodent, Dasyprocta spp. (Tobler et al 2008, Botelho et al 2012, Michalski et al 2015, Lizcano et al 2016.…”

“…In strictly protected areas that are surrounded by other undisturbed forests, Carnivora and Artiodactyla are among the richest mammalian orders Oliveira 2012, Carvalho et al 2014), whereas in protected areas that are subjected to anthropogenic impacts in its surroundings, although Carnivora may still be the most speciose order, Rodentia and Xenarthra may replace Artiodactyla and become the most species-rich orders (Ahumada et al 2013, Michalski et al 2015, Lizcano et al 2016). This could be the result of a time-lag between deforestation and/or hunting, and species extirpation, or result from location, resources availability, species resilience and proximate benefits of secondary vegetation (Tobler et al 2008, Pickles et al 2011, Botelho et al 2012, Galetti et al 2015, Melo et al 2015, Meyer et al 2015.…”

“…It has been used to determine richness and diversity, abundance, habitat preferences and activity patterns, and has been suggested to be among the best methods for conducting minimally invasive mammal surveys (van Schaik and Griffiths 1996, Maffei et al 2005, Goulart et al 2009, Ahumada et al 2011, Harmsen et al 2011, Munari et al 2011, Gonçalves 2013, Michalski et al 2015, Lizcano et al 2016.…”

“…is normally the most abundant (Tobler et al 2008, Botelho et al 2012, Michalski et al 2015, Lizcano et al 2016). Studies of medium-sized and large mammals in the State of Roraima are relatively recent and the focus has been mainly on the mammals of protected areas, such as Maracá Ecological Station (Mendes Pontes 1997, 1999, Fragoso 1998, Mendes Pontes et al 2007, and the Waimiri-Atroari (Mazurek et al 2000), Yanomami and Macuxi Indian reserves (Fragoso 2004).…”