Dados do Trabalho

TÍTULO

ASSESSING THE POTENTIAL SOUTHWARD MOVEMENT OF WHITE-NOSE SYNDROME THROUGH MEXICAN KARST SYSTEMS

Resumo

White-nose Syndrome (WNS) is a virulent fungal disease that was first documented in the Americas in a cave in upstate New York in the winter of 2006. Since this first documentation, the disease has rapidly spread in all directions, and caused a precipitous decline in North American cavernicolous bat populations, with mortality rates in some infected populations reaching 100%. The fungus that causes the disease, Pseudogymnoascus destructans (Pd), has been detected in caves in Texas leading researchers to wonder what the southernmost boundary of disease spread is, or if one even exists. Further, the recent documentation of Pd on multiple Mexican free-tailed bats in Texas is particularly concerning. This species has a broad migratory range, extending from the central United States to as far south as Bolivia. It is possible that Mexican Free-tailed bats will spread Pd from cave to cave in Mexico and Central and South America as they stopover during their migration. 1.) Presence of Pd, 2.) An existing substrate to act as growth medium (this can include almost anything organic, including guano and dead insects) and 3.) Suitable internal microclimate to facilitate fungal growth. I have assembled data on cave microclimates in Texas and Mexico with the aim to generate a predictive model of the potential spread of Pd through karst systems in Mexico, Central America, and South America based on external features which correlate with suitable internal microclimates for fungal growth. Throughout my previous work with the Texas Winter Bat Project at the Texas A&M University Natural Resources Institute, I have assembled a dataset of winter microclimates for 54 caves across the state of Texas. This data will be combined with microclimate data collected from dataloggers deployed in Mexico this summer. These microclimate data consist of hourly recordings of temperature and humidity over the course of the winter season. From this data, caves are determined to either be “suitable” or “unsuitable” or for fungal growth depending on the length of time each dataset spends within the "highly suitable" range for fungal growth. These caves' microclimates were then assessed for their correlation with external features such as elevation, external climate, geology, and lithology to create a model of areas most likely to sustain microclimates suitable for the growth of Pd, and therefore, the possibility of contracting WNS. The work I am presenting details the continued southward spread of Pd, and the likely areas for Pd to establish itself in Mexico, Central, and South America according to the findings from my model. By identifying areas of high risk for Pd establishment, researchers can target their monitoring efforts and be prepared for the eventual fallout should WNS establish itself in their area.

Palavras-chave

Bat, pathogen, habitat suitability, spread