FINAL REPORT GENETIC CHARACTERIZATION OF POPULATIONS OF THE NONINDIGENOUS BURMESE PYTHON IN EVERGLADES NATIONAL PARK

Abstract

The Burmese Python, Python molurus bivittatus has become established in Everglades National Park (ENP). Because pythons have been sampled from geographically disparate locations in ENP, it is possible that these populations are the result of independent introductions. The full extent of the invasion of Python molurus bivittatus in ENP is not known. Burmese pythons were first reported as established in ENP by Meshaka et al. (2000). Since then, the number of pythons captured or found dead in and around ENP has increased dramatically. Young snakes as well as female snakes with eggs have been captured, further providing evidence of reproduction. Knowledge of population structure is fundamental for developing a control and management plan for an invasive species, but the size, geographical extent, or degree of connectedness among populations in and around ENP is not known. Molecular data including mitochondrial DNA sequences and microsatellite loci were used to (1) examine the genetic diversity of populations of Python molurus bivittatus in ENP, (2) determine whether the distribution of genetic diversity suggests that the populations sampled to date are heterogeneous, to be managed separately, or are likely part of a single large population, and (3) determine if there is genetic evidence for parthenogenetic reproduction in Python molurus bivittatus in ENP. Multiple analyses including assignment methods and Fstatistics revealed that the ENP Burmese pythons are genetically distinct from pythons sampled from Vietnam, but display little genetic differentiation within the Park, with the exception of a few outliers. The lack of genetic differentiation of most Burmese Pythons in ENP may indicate either a panmictic freely interbreeding population in the Park, or alternatively, limited genetic variation in the captivebred populations that are the likely source of these snakes. Sampling of mothers and offspring provided no evidence of parthenogenetic reproduction in ENP pythons. Management strategies should focus on controlling an established population that is with a few exceptions, not genetically differentiated.

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