Geology topics

Jeremy Dixon

Publications and source records attributed to Jeremy Dixon.

3 recordsLinked to original sources

USGS2023

Survey optimization for invasive Burmese pythons informed by camera traps

The Burmese python ( Python bivittatus ) is an invasive predator responsible for broad mammal declines in South Florida, United States. Despite their large size, pythons remain cryptic and require multifaceted approaches for detection. We evaluated a novel technique by deploying camera traps at known locations of radiotagged pythons in the Florida Keys. We estimated daily detection probabilities of snakes and plotted diel activity patterns. Our results suggest camera traps can effectively survey pythons but seasonality and camera trigger mechanisms affect utility. Pythons were most detectable with time-lapse camera traps and more detectable in winter. The diel activity pattern of pythons peaked midday through early afternoon, indicating an optimal survey time for other search methods. Artificial intelligence can alleviate photo volume, so we recommend a combination of motion detection and time-lapse with shorter time (1 min) intervals for python-specific surveys and where camera traps are deployed to monitor mammals to improve passive python detection.

Florida↗

USGS2023

Burmese pythons in Florida: A synthesis of biology, impacts, and management tools

Burmese pythons ( Python molurus bivittatus ) are native to southeastern Asia, however, there is an established invasive population inhabiting much of southern Florida throughout the Greater Everglades Ecosystem. Pythons have severely impacted native species and ecosystems in Florida and represent one of the most intractable invasive-species management issues across the globe. The difficulty stems from a unique combination of inaccessible habitat and the cryptic and resilient nature of pythons that thrive in the subtropical environment of southern Florida, rendering them extremely challenging to detect. Here we provide a comprehensive review and synthesis of the science relevant to managing invasive Burmese pythons. We describe existing control tools and review challenges to productive research, identifying key knowledge gaps that would improve future research and decision making for python control.

Florida↗

USGS2023

Telescoping prey selection in invasive Burmese pythons spells trouble for endangered rodents

The allometric scaling of predators and their prey is well established within snakes (i.e., gape-width limits maximum prey sizes). However, while some species exhibit ontogenetic shifts to larger prey as they grow, others exhibit telescoping prey selection and continue to consume small prey in addition to larger prey. The Burmese python ( Python bivittatus ) is a large dietary generalist constrictor native to Southeast Asia that is established in South Florida (USA). As part of survey efforts at the southern invasion front in the Florida Keys, we used camera traps to document predation on endangered Key Largo cotton mice ( Peromyscus gossypinus allapaticola ) by an adult female Burmese python. These images represent the first photo documentation of predation attempts upon a federally endangered species in the python's invasive range, but we note three additional instances of Key Largo cotton mice in the gut contents of euthanized pythons from Key Largo. These observations suggest Burmese pythons exhibit telescoping prey selection behavior where even small rodents (<30 g) are viable prey for adult snakes. However, based on the number of documented strikes with failed predation events and low frequency of occurrence in gut contents, we suspect mice may be less common prey items for adult (i.e., >185 cm SVL) pythons relative to cotton mouse abundance in the environment. However, we also documented endangered Key Largo woodrats ( Neotoma floridana smalli ) and Key Largo cotton mice collecting and consuming the shed skins of pythons, which suggests the two rodent species remain naïve to the threat of these invasive predators. Further understanding of the impact of Burmese pythons on native prey communities can help inform efforts to minimize biodiversity loss along their invasion fronts.

Food Webs↗