Using a novel model approach to assess the distribution and conservation status of the endangered Baird's tapir

Abstract:

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 pbkp_redictions 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 presence-only (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 pbkp_redictive maps for each model framework. A hotspot analysis (Gi*) was used to identify habitat cores from the pbkp_redicted 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 pbkp_redictive 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 pbkp_redicted 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 pbkp_redictor layers and improvements to the model framework.

Año de publicación:

2017

Keywords:

• point process model
• Conservation
• maxent
• occupancy model
• tapir
• hotspots
• habitat cores
• Tapirus bairdii

Fuente:

scopus