Subterranean Refuge Use by Burmese Pythons (Python bivittatus) in Southwestern Florida

Access to subterranean refugia, such as animal burrows, can affect the ecology and life history of wildlife in an array of habitat types. Subterranean refugia are commonly used for thermal refuge, for shelter from predators, or as suitable locations for nesting and/or brooding offspring; because of this, refugia can potentially impact rates of survivorship and recruitment. In southwestern Florida, Burmese pythons (Python bivittatus), an established and highly impactful invasive species, have been observed using subterranean refugia on numerous occasions. Because python management is an utmost priority in Florida, understanding the potential implications of this behavior is key to mitigating python impacts on native wildlife. We used 29 radio-telemetered Burmese pythons to investigate the extent to which pythons used subterranean refugia in the southwestern portion of their Florida range. We explored spatiotemporal patterns of refuge use and quantitatively assessed how python sex, reproductive season, and habitat type affected the probability of using different types of refugia. We observed pythons using four types of refugia, including Gopher Tortoise burrows, Nine-banded Armadillo burrows, and natural and anthropogenic ground-based cavities. Pythons used these refugia for seeking thermal refuge, aggregating, breeding, and nest brooding, and they were most likely to use refugia during their breeding and nesting seasons. Nine python nests, representing 71% of those discovered during the study, were oviposited and brooded in Gopher Tortoise or Nine-banded Armadillo burrows. Implications of this behavior warrant further assessment and incorporation into management strategies as they may affect Burmese python recruitment, survival, and dispersal.