An assessment of the terrestrial mammal communities in forests of Central Panama, using camera-trap surveys

Abstract

a b s t r a c tThe Isthmus of Panama, part of the planet's third largest megadiversity hotspot, and connecting the faunas of North and South America, has lost more than half of its forest due to agriculture and economic development. It is unknown to what degree the remaining forest, which is fragmented and subject to poaching, still supports the wildlife diversity found in intact forests. Here, we use camera-trap surveys to assess whether forests in Central Panama, the narrowest and most disturbed portion of the Isthmus, still have intact communities of medium-and large-bodied terrestrial mammals. During 2005-2014, we collected camera-trap survey data from 15 national parks and forest fragments on both sides of the Panama Canal, and compared these to similar data from two sites in the intact Darién National Park in Eastern Panama, the nearest available reference. We found that most sites in Central Panama -including some of the national parks -had lower mammal species richness and evenness than the reference sites, and less structurally-complex mammal communities. Forests in Central Panama had little or no apex predators and large terrestrial frugivores, with the exception of two sites directly connected to the reference site. Our results indicate that the terrestrial mammal community in forests of Central Panama is currently degraded, even inside national parks. These data provide a baseline for evaluating the success of conservation efforts to prevent the Panamanian Isthmus to become a bottleneck for movement of animals.

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

“…At the fishbone human settlements IA Bom Jesus and IA Entre Rios, due to the fact that Tayassu pecari has been extirpated, dominance was lower than in PA Maracá (and diversity higher), but was higher still than PA Uatumã (and diversity lower). In these impacted areas the medium-sized Dasyprocta leporina had the highest dominance, possibly replacing Tayassu pecari, as seems also to be the case in Meyer et al (2015) where agoutis, (Dasyprocta leporina) were the most abundant, causing a decline in evenness and dominance.…”

“…In our previous studies (Mendes Pontes 2004, Mendes Pontes et al 2007, Mendes Pontes et al 2012, Melo et al 2015, we showed that in the highly heterogeneous vegetation mosaics of the northernmost Guyana shield the structure of the terrestrial mammalian assemblages was shaped by forest type and heterogeneity, which, in turn, is directly connected with resource availability. Species richness and diversity may vary between protected and impacted areas, with the latter in most studies presenting a lower number of species due to hunting (Lopes and Ferrari 2000, Peres and Nascimento 2006, Michalski and Peres 2007, Sampaio et al 2010, Ahumada et al 2011, Melo et al 2015, Meyer et al 2015. Accordingly, the richest area was PA Uatumã, located south of the Guyana shield, closest to central Amazonia, the natural vegetation cover for which is dense ombrophilous forests, followed by IA Entre Rios, which is located in the transition between the dense ombrophilous terra firme forests of the south of the Guyana shield, and the seasonally-dry forest mosaics of central Guyana shield, and the poorest areas were PA Maracá and IA Bom Jesus, in the northernmost Guyana shield, where the vegetation is mainly seasonally-dry forest mosaics interspersed with extensive areas of savannas (See Hoorn et al (2010)).…”

“…Richness and diversity of terrestrial large mammals in the Neotropics is higher in strictly protected areas that are surrounded by other undisturbed forests than in those subject to deforestation and hunting in its surroundings, and is lowest in highly impacted areas (Tobler et al 2008, Ahumada et al 2011, Pickles et al 2011, Botelho et al 2012, Santos and Oliveira 2012, Carvalho et al 2014, Melo et al 2015, Meyer et al 2015. 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).…”

“…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.…”

“…The first to become rare or extinct from the impacted areas are the large-bodied, terrestrial mammals such as white-lipped peccary, Tayassu pecari, jaguar, Panthera onca, giant ant-eater, Myrmecophaga tridactyla, tapir, Tapirus terrestris, and puma, Puma concolor, with T. pecari being one of the most sensitive, and therefore, the first to go locally or, regionally, extinct (Azevedo and Conforti 2008, Peres 1996, Reyna-Hurtado and Tanner 2007, Naranjo and Bodmer 2007, Richard-Hansen et al 2014, Melo et al 2015, Meyer et al 2015. This is due to their higher energetic demands, larger home ranges, slower reproductive rates, and densities (Peres 2000, Brown and Brown 1992, Grelle et al 2006.…”