WARC researchers are addressing an urgent need to identify specific habitat use of pythons on Key Largo, FL.
The Science Issue and Relevance: Burmese pythons were first detected in North Key Largo in 2007, with evidence of reproduction in 2016. Over 60 pythons have been captured in Key Largo since 2007. Necropsies of these show evidence of Key Largo wood rat depredation, and it is possible they also prey upon other listed species, such as the Key Largo cotton mouse and American crocodile. Several other federally endangered species in the Keys such as the Key deer, Lower Keys marsh rabbit, and silver rice rat, and others may be extremely vulnerable to python predation. The Recovery Plans for the aforementioned species all have recovery actions that seek to reduce or eliminate mortality from non-native predators, such as pythons. The threat that pythons pose to native wildlife in the Upper Keys, combined with pressures from other non-native species, namely feral cats, could be disastrous for federally protected species and potentially lead to their extinction.
This project will address an urgent need to identify specific habitat use of pythons on Key Largo (including Crocodile Lake National Wildlife Refuge, Dagny Johnson Botanical State Park, and John Pennekamp Coral Reef State Park). This information is needed to focus python removal efforts and prevent the extinction of the Key Largo wood rat and Key largo cotton mouse. Pythons are cryptic (their coloration serves to camouflage them in the environment) and in the absence of substantial data documenting habitat use on Key Largo, it is difficult to determine what habitats are being utilized (and to what degree). Scout python work (i.e., using pythons to locate other pythons; see Smith et al. 2016) can help shed light on the presence (or absence) of breeding females within the study site, and the selection of breeding sites. Given the relatively small size of the conservation lands on North Key Largo, scout python work could allow us to identify high-density python locations and inform future removal efforts to slow both population growth and the spread of pythons across the Florida Keys. Python numbers in Key Largo are not thought to be as high as in other parts of southern Florida, so there is an opportunity to get ahead of this problem before long-lasting ecological damage is caused. Because of its location within the Florida Keys, reduction of the python threat in Key Largo would benefit wildlife in areas further south in the Middle and Lower Keys where pythons have not yet been established.
Methodology for Addressing the Issue: Pythons will be captured during routine searches or opportunistically in Key Largo. Captured pythons of breeding size (more than 7 feet long) will have a very-high-frequency (VHF) radio tag and an accelerometer internally implanted. Each instrumented python will be located via VHF telemetry two or more times per week. Individual pythons will be followed closely during mating season (November through March) to find mating groups and remove other pythons from the population.
A python detector dog “Percy” was purchased with a grant from the Ocean Reef Community Association. Percy has been successful at finding wild pythons in the Everglades and will be used to survey areas for the presence of pythons, including core occupied habitat for the Key Largo wood rat and Key Largo cotton mouse, areas adjacent to scout pythons, nesting areas for American crocodiles and areas with recent python sightings.
Future Steps: Future efforts could include the continued use of scout pythons, telemetry, and detection dogs to track pythons and their impacts on native wildlife and habitat use. Global positioning system (GPS) technology will continue to play an important role, allowing us to refine our understanding of python spatial distribution throughout the Florida Keys. These efforts will provide a better understanding of the biology and ecological impact of invasive pythons and provide insight into ways to exploit their biology to control their population.
- Overview
WARC researchers are addressing an urgent need to identify specific habitat use of pythons on Key Largo, FL.
Invasive Burmese python in the Greater Everglades (credit: Brian Smith, USGS) The Science Issue and Relevance: Burmese pythons were first detected in North Key Largo in 2007, with evidence of reproduction in 2016. Over 60 pythons have been captured in Key Largo since 2007. Necropsies of these show evidence of Key Largo wood rat depredation, and it is possible they also prey upon other listed species, such as the Key Largo cotton mouse and American crocodile. Several other federally endangered species in the Keys such as the Key deer, Lower Keys marsh rabbit, and silver rice rat, and others may be extremely vulnerable to python predation. The Recovery Plans for the aforementioned species all have recovery actions that seek to reduce or eliminate mortality from non-native predators, such as pythons. The threat that pythons pose to native wildlife in the Upper Keys, combined with pressures from other non-native species, namely feral cats, could be disastrous for federally protected species and potentially lead to their extinction.
This project will address an urgent need to identify specific habitat use of pythons on Key Largo (including Crocodile Lake National Wildlife Refuge, Dagny Johnson Botanical State Park, and John Pennekamp Coral Reef State Park). This information is needed to focus python removal efforts and prevent the extinction of the Key Largo wood rat and Key largo cotton mouse. Pythons are cryptic (their coloration serves to camouflage them in the environment) and in the absence of substantial data documenting habitat use on Key Largo, it is difficult to determine what habitats are being utilized (and to what degree). Scout python work (i.e., using pythons to locate other pythons; see Smith et al. 2016) can help shed light on the presence (or absence) of breeding females within the study site, and the selection of breeding sites. Given the relatively small size of the conservation lands on North Key Largo, scout python work could allow us to identify high-density python locations and inform future removal efforts to slow both population growth and the spread of pythons across the Florida Keys. Python numbers in Key Largo are not thought to be as high as in other parts of southern Florida, so there is an opportunity to get ahead of this problem before long-lasting ecological damage is caused. Because of its location within the Florida Keys, reduction of the python threat in Key Largo would benefit wildlife in areas further south in the Middle and Lower Keys where pythons have not yet been established.
Sources/Usage: Public Domain.Study area on North Key Largo, including grid of hexagonal cells used to monitor endangered Key Largo woodrat (Public domain.) Methodology for Addressing the Issue: Pythons will be captured during routine searches or opportunistically in Key Largo. Captured pythons of breeding size (more than 7 feet long) will have a very-high-frequency (VHF) radio tag and an accelerometer internally implanted. Each instrumented python will be located via VHF telemetry two or more times per week. Individual pythons will be followed closely during mating season (November through March) to find mating groups and remove other pythons from the population.
A python detector dog “Percy” was purchased with a grant from the Ocean Reef Community Association. Percy has been successful at finding wild pythons in the Everglades and will be used to survey areas for the presence of pythons, including core occupied habitat for the Key Largo wood rat and Key Largo cotton mouse, areas adjacent to scout pythons, nesting areas for American crocodiles and areas with recent python sightings.
Future Steps: Future efforts could include the continued use of scout pythons, telemetry, and detection dogs to track pythons and their impacts on native wildlife and habitat use. Global positioning system (GPS) technology will continue to play an important role, allowing us to refine our understanding of python spatial distribution throughout the Florida Keys. These efforts will provide a better understanding of the biology and ecological impact of invasive pythons and provide insight into ways to exploit their biology to control their population.
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