Aim:We test a new species distribution modelling (SDM) framework, while comparing results to more common distribution modelling techniques. This framework allows for the combination of presence-only (PO) and presence-absence (PA) data and accounts for imperfect detection and spatial bias in presence data. The new framework tested here is based on a Poisson point process model, which allows for predictions of population size. We compared these estimates to those provided by experts on the species. Species and Location: Presence data on Baird's tapir (Tapirus bairdii) throughout its range from southern México to northern Colombia were used in this research, primarily from the years 2000 to 2016. Methods: Four SDM frameworks are compared as follows: (1) Maxent, (2) a presenceonly (PO) SDM based on a Poisson point process model (PPM), (3) a presence-absence (PA) SDM also based on a PPM and (4) an Integrated framework which combines the previous two models. Model averaging was used to produce a single set of coefficient estimates and predictive maps for each model framework. A hotspot analysis (Gi*) was used to identify habitat cores from the predicted intensity of the Integrated model framework. Results: Important variables to model the distribution of Baird's tapir included land cover, human pressure and topography. Accounting for spatial bias in the presence data affected which variables were important in the model. Maxent and the Integrated model produced predictive maps with similar patterns and were considered to be more in agreement with expert knowledge compared to the PO and PA models.Main conclusions: Total abundance as predicted by the model was higher than expert opinion on the species, but local density estimates from our model were similar to available independent assessments. We suggest that these results warrant further validation and testing through collection of independent test data, development of more precise predictor layers and improvements to the model framework.
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.
ABSTRACT:Gammaherpesviruses (GHVs) have been identified in many species and are often associated with disease. Recently, we characterized three novel felid GHVs in domestic cats (Felis catus), bobcats (Lynx rufus), and pumas (Puma concolor). We investigated whether freeranging ocelots (Leopardus pardalis) and bobcats are infected with additional GHVs. We screened DNA samples from ocelots on Barro Colorado Island, Panama, and bobcats in western Colorado, US, by using a degenerate nested PCR that targets the GHV glycoprotein B gene. We identified a novel GHV glycoprotein B sequence in two ocelots and a second novel sequence in a bobcat, which is distinct from the previously characterized bobcat GHV (Lynx rufus GHV 1). Utilizing additional degenerate and virus-specific PCRs, we extended these sequences to include 3.4 kilobases of the GHV glycoprotein B and DNA polymerase genes. These sequences identify the first GHV detected in ocelots and the second GHV in bobcats. These viruses were provisionally named L. pardalis GHV 1 and Lynx rufus GHV 2, respectively. The viruses are most closely related to recently identified GHVs of the Percavirus genus found in domestic cats (F. catus GHV 1) and bobcats (L. rufus GHV 1), suggesting that a cluster of felid GHVs exists within the Percavirus genus.
We collected details on the predation of four agoutis (Dasyprocta punctata) by ocelots (Leopardus pardalis). All kills were made outside of the typical agouti activity period (<0500 h). Agoutis were captured from behind and killed with a bite through the back of the skull. The kill sites for two female agoutis were significantly closer to their den sites than expected, while kill sites for two males were not. All carcasses were completely covered by leaves during the day and were fed on during night hours. Predation by ocelots can be a significant cause of mortality for agoutis at Barro Colorado Island (BCI). RESUMENColectamos detalles en la depredación de 4 agoutis (Dasyprocta punctata) por ocelotes (Leopardus pardalis). Todas las depredaciones fueron fuera del periodo típico de actividad (<0500 h). Los agoutis fueron capturados por detrás y muertos con una mordida en la parte trasera del cráneo. Los lugares de muerte en las dos hembras fueron significativamente cerca de sus guaridas, mientras que los machos no. Los cadáveres fueron completamente cubiertos con hojarasca durante el día y fueron consumidos solamente durante la noche. La depredación por ocelotes puede ser una causa significativa de mortalidad de los agoutis en BCI.
The rise of the Panamanian Isthmus 3–4 million years ago enabled the first dispersal of mammals between North and South America in what is known as the Great American Biotic Interchange. Modern deforestation threatens the historic forest connectivity and creates new habitat for open-country species, as documented by recent expansions of North American coyotes (Canis latrans) and South American crab-eating foxes (Cerdocyon thous) into Central America. We used camera traps to map the expansions of these species into eastern Panama and found that, by 2015, coyote populations had colonized most agricultural area west of Lago Bayano. Most of our camera arrays east of this point documented crab-eating foxes, and evidence from roadkills showed some foxes had advanced farther west, but we never documented both species at the same camera-trap array, suggesting the possibility of fine-scale spatial avoidance. We used a data fusion approach to build species distribution models combining our camera surveys with records from the literature and roadkill. While the auxiliary data improved the predictive accuracy for both species, few clear habitat patterns emerged, which might reflect the generalist tendencies of these canids, or the fact that both are in the early stages of colonizing the region. Camera-trap photos showed that both species were nocturnal and revealed some dog-like morphology in coyotes, which could indicate their recent hybridization with dogs (Canis familiaris). Our continued monitoring of the Darién documented single coyotes moving through the western edge of the area in 2016 and 2018. This leaves only the great Darién forests between coyotes and South America. If deforestation continues in the region, these two invasive canids could represent the first of a new, Not-So-Great American Biotic Interchange, where generalist species adapted to human disturbance cross continents and threaten native biota.
Habitat fragmentation is a primary driver of wildlife loss, and establishment of biological corridors is a common strategy to mitigate this problem. A flagship example is the Mesoamerican Biological Corridor (MBC), which aims to connect protected forest areas between Mexico and Panama to allow dispersal and gene flow of forest organisms. Because forests across Central America have continued to degrade, the functioning of the MBC has been questioned, but reliable estimates of species occurrence were unavailable. Large mammals are suitable indicators of forest functioning, so we assessed their conservation status across the Isthmus of Panama, the narrowest section of the MBC. We used large-scale camera-trap surveys and hierarchical multispecies occupancy models in a Bayesian framework to estimate the occupancy of 9 medium to large mammals and developed an occupancy-weighted connectivity metric to evaluate species-specific functional connectivity. White-lipped peccary (Tayassu pecari), jaguar (Panthera onca), giant anteater (Myrmecophaga tridactyla), white-tailed deer (Odocoileus virginianus), and tapir (Tapirus bairdii) had low expected occupancy along the MBC in Panama. Puma (Puma concolor), red brocket deer (Mazama temama), ocelot (Leopardus pardalis), and collared peccary (Pecari tajacu), which are more adaptable, had higher occupancy, even in areas with low forest cover near infrastructure. However, the majority of species were subject to ࣙ1 gap that was larger than their known dispersal distances, suggesting poor connectivity along the MBC in Panama. Based on our results, forests in Darien, Donoso-Santa Fe, and La Amistad International Park are critical for survival of large terrestrial mammals in Panama and 2 areas need restoration. Efectividad de Panamá como un Puente Terrestre Intercontinental para Mamíferos MayoresResumen: La fragmentación del hábitat es un causante primario de la pérdida de biodiversidad, y el establecimiento de corredores biológicos es una estrategia común para mitigar este problema. El Corredor Biológico Mesoamericano (CBM) es un ejemplo notable que pretende conectaráreas boscosas protegidas entre México y Panamá para permitir la dispersión y flujo genético de organismos del bosque. El funcionamiento del CBM se ha cuestionado debido a que la degradación de los bosques en Centroamérica continúa, pero no se dispone de estimaciones confiables de la ocurrencia de especies. Los mamíferos grandes son indicadores adecuados del funcionamiento de los bosques tropicales Por lo tanto evaluamos su estado de conservación en el Istmo de Panamá, la sección más angosta del CBM. Utilizamos muestreos con cámaras trampa y modelos de ocupación para múltiples especies bajo un modelo Bayesiano para estimar la ocupación de 9 especies de mamíferos medianos a grandes, y desarrollamos una métrica de conectividad ponderada por la ocupación para evaluar la conectividad funcional para cada especie. El puerco de monte (Tayassu pecari), jaguar (Panthera onca), hormiguero gigante (Myrmecophaga tridactyla), venado cola...
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