Wed, Aug 04, 2021:On Demand
Background/Question/Methods
The collared peccary’s (Pecari tajacu) preferred habitat largely consists of tropical and subtropical deciduous forests and shrublands. They currently occupy a large area spanning from southern North America to northern South America, but climate and land use changes are altering their distribution. Previous range expansion literature suggests that there is a limited amount of collaborative agreement upon the northern range expansion of the collared peccary. We compiled literature sources and collared peccary records (from iNaturalist, VertNet, IDigBio, and Global Biodiversity Information Facility on 20 July 2020) to identify the geographical range expansion. Over half our data (55.06%) is derived from iNaturalist’s research-grade observations. We used Maximum Entropy Modeling (Maxent) for statistical analysis. We filtered data to remove observations of domesticated animals, only retained observations with >5 km accuracy, and subsampled to minimize the negative effects of convenience sampling by the general public. We included environmental variables that we believed to a priori to influence collared peccary habitat selection. We assessed model performance using the area under the receiver operating curve (AUC; ranges 0-1; 1 indicates perfect fit) and implemented jackknifing to evaluate the importance of each environmental covariate to collared peccary habitat suitability.
Results/Conclusions Our model was a good fit for our data (AUC 0.71). Land cover classification (35.1%), precipitation seasonality (18.8%), and minimum temperature during the coldest month (13.3%) were the most important (>10%) contributors to our model. Viable habitat was recorded in the southern states of the U.S. with considerable potential locations in New Mexico, California, Nevada, and Utah. There were no sightings north or west of the Colorado river, indicating the river is a dispersal barrier. It is also observed that climate and habitat type are the deciding factors in how far north they expand. Habitat suitability increased with increased precipitation seasonality and increased minimum temperature during the coldest month. Alterations to these factors due to climate and land use change will affect continued range expansion in the future.
Results/Conclusions Our model was a good fit for our data (AUC 0.71). Land cover classification (35.1%), precipitation seasonality (18.8%), and minimum temperature during the coldest month (13.3%) were the most important (>10%) contributors to our model. Viable habitat was recorded in the southern states of the U.S. with considerable potential locations in New Mexico, California, Nevada, and Utah. There were no sightings north or west of the Colorado river, indicating the river is a dispersal barrier. It is also observed that climate and habitat type are the deciding factors in how far north they expand. Habitat suitability increased with increased precipitation seasonality and increased minimum temperature during the coldest month. Alterations to these factors due to climate and land use change will affect continued range expansion in the future.