Gretchen Anderson, MSc (Former Employee)
Science and Products
Biology, Impacts and Control of Invasive Reptiles in the Everglades
Invasive species are considered to be second only to habitat degradation in terms of negative impacts on the Earth’s ecosystems, and our scientists make up a significant proportion of the global expertise in the rapidly-growing problem of invasive reptiles.
Ecology and Control of Invasive Reptiles in Florida
This project involves development of tools for the detection and control of invasive reptiles in Florida, with an emphasis on pythons and tegu lizards. The goals are to reduce the risk of reptile invasions, investigate early detection methods, maintain rapid response capacity, and understand invasive reptile population biology and ecology to inform management options.
USGS Everglades Research Office - Florida
The Daniel Beard Center in Everglades National Park provides the base for most of the field work done on the control of invasive reptiles by USGS Fort Collins Science Center staff. The team works in Everglades National Park, Big Cypress National Preserve, Crocodile Lake National Wildlife Refuge, and other parts of the Greater Everglades Ecosystem focusing on, among other species of concern...
Photographic sequence of brooding Burmese python (Python bivittatus) and associated temperature of record-sized nest in Big Cypress National Preserve, FL, June to August 2022 Photographic sequence of brooding Burmese python (Python bivittatus) and associated temperature of record-sized nest in Big Cypress National Preserve, FL, June to August 2022
Select photographic sequence of a Burmese Python (Python bivittatus) nesting in the wild within a concrete pipe from 01 June 2022 through 01 August 2022 in Big Cypress National Preserve within the Greater Everglades Ecosystem, Florida, USA. This python was tracked to an area of abandoned construction pipes and discovered inside to have oviposited. Throughout incubation, the python was...
Photo-documented sequences from 01 Jun 2021 - 30 Aug 2021 showing novel interactions between intraguild predators in southern Florida, USA, bobcat and Burmese python Photo-documented sequences from 01 Jun 2021 - 30 Aug 2021 showing novel interactions between intraguild predators in southern Florida, USA, bobcat and Burmese python
Entire photo-documented sequence from 01 June 2021-09 September 2021, including novel interactions between intraguild predators in southern Florida - the native bobcat (Lynx rufus) and the invasive Burmese python (Python bivittatus). A bobcat depredated an unguarded Burmese python nest and subsequently the python exhibited nest defense behavior following the return of both animals to the...
Filter Total Items: 13
Coelomic foreign bodies in wild-caught Python spp. in the Greater Everglades Ecosystem, Florida, USA Coelomic foreign bodies in wild-caught Python spp. in the Greater Everglades Ecosystem, Florida, USA
Burmese pythons (Python molurus bivittatus) and African rock pythons (Python sebae) have established invasive populations in southern Florida, severely disrupting local ecosystems. We analysed necropsy data from 2,179 pythons captured between 2006 and 2022, revealing nine cases of coelomic foreign bodies, primarily consisting of bird beaks, which presumably entered the coelom following
Authors
Gretchen E. Anderson, McKayla M. Spencer, Ray W. Snow, Andrea Currylow, Frank N. Ridgley, Bryan G. Falk, Amy A. Yackel Adams
Wild Burmese python nest site selection, thermogenesis, and brooding behaviors in the Greater Everglades Ecosystem Wild Burmese python nest site selection, thermogenesis, and brooding behaviors in the Greater Everglades Ecosystem
Invasive Burmese pythons (Python bivittatus) are extremely cryptic animals. Although their conservation status in their native range is Vulnerable, in the Greater Everglades Ecosystem (Florida, USA) they have become a dominant destructive force and usually are immediately removed whenever found. This poses a paradox where removals are occurring, yet the study and understanding of python...
Authors
Andrea Faye Currylow, Lisa Marie McBride, Gretchen Erika Anderson, Jacquelyn C. Guzy, Matthew F. McCollister, Christina M. Romagosa, Kristen Hart, Amy A. Yackel Adams
Double take: Ingestion of two rats by a juvenile Burmese Python (Python bivittatus) in Big Cypress National Preserve, FL, USA Double take: Ingestion of two rats by a juvenile Burmese Python (Python bivittatus) in Big Cypress National Preserve, FL, USA
No abstract available.
Authors
Teah M. Evers, Andrea F. Currylow, Mark Robert Sandfoss, Lisa Marie McBride, Christina M. Romagosa, Wesley W. Boone, Jacquelyn C. Guzy, Gretchen Erika Anderson, Kristen Hart, Matthew McCollister, Amy A. Yackel Adams
Flooding-induced failure of an invasive Burmese Python nest in southern Florida Flooding-induced failure of an invasive Burmese Python nest in southern Florida
It is important to understand the factors affecting the reproductive success of an invasive species to estimate population size and develop management plans. There remains much we do not understand about the reproductive biology of invasive Burmese Pythons in both their native and invasive range. Oviposition site selection is an important factor in determining reproductive success as...
Authors
Mark Robert Sandfoss, Lisa Marie McBride, Gretchen Erika Anderson, Amanda Marie Kissel, Matthew McCollister, Christina M. Romagosa, Amy A. Yackel Adams
See a snake, save a snake: Use of external tags to prevent mortality in pythons used in research. See a snake, save a snake: Use of external tags to prevent mortality in pythons used in research.
No abstract available.
Authors
Gretchen Erika Anderson, Lisa Marie McBride, Mark Robert Sandfoss, Amy A. Yackel Adams
Florida Kingsnake (Lampropeltis floridana) consumes a juvenile Burmese Python (Python molurus bivitattus) in southern Florida Florida Kingsnake (Lampropeltis floridana) consumes a juvenile Burmese Python (Python molurus bivitattus) in southern Florida
The Burmese python (Python molurus bivittatus) is an invasive constrictor established across southern Florida. These snakes are dietary generalists with large home ranges and broad habitat requirements and their introduction has had severe impacts on native species and ecosystems in the region. We describe the first observation of a Florida kingsnake (Lampropeltis floridana) that...
Authors
Peter F. Crawford, Jose A. Torres, Jacquelyn C. Guzy, Andrea Faye Currylow, Lisa Marie McBride, Gretchen Erika Anderson, Matthew F. McCollister, Christina M. Romagosa, Amy A. Yackel Adams, Kristen Hart
Testicular abnormalities in the invasive Argentine Black-and-White Tegu lizard (Salvator merianae) in the Florida Everglades Testicular abnormalities in the invasive Argentine Black-and-White Tegu lizard (Salvator merianae) in the Florida Everglades
No abstract available.
Authors
Kyra Woytek, Gretchen Erika Anderson, Kevin Donmoyer, Frank Ridgley, Christina Romagosa, Amy A. Yackel Adams, Andrea Faye Currylow
Maximum clutch size of an invasive Burmese Python (Python bivittatus) in Florida, USA Maximum clutch size of an invasive Burmese Python (Python bivittatus) in Florida, USA
Native to southeastern Asia, the Burmese Python (Python bivittatus Kuhl 1820) is an invasive species established in southern Florida (Snow et al. 2007; Krysko et al. 2016; Krysko et al. 2019). Pythons are documented as having negative effects on the Greater Everglades Ecosystem and they have proven to be a complex problem for managers trying to control populations (Guzy et al. 2023)...
Authors
Andrea Faye Currylow, Teah Evers, Gretchen Erika Anderson, Lisa Marie McBride, Matthew McCollister, Jacquelyn C. Guzy, Christina Romagosa, Kristen Hart, Amy A. Yackel Adams
Natives bite back: Depredation and mortality of invasive juvenile Burmese pythons (Python bivittatus) in the Greater Everglades Ecosystem Natives bite back: Depredation and mortality of invasive juvenile Burmese pythons (Python bivittatus) in the Greater Everglades Ecosystem
Burmese pythons (Python bivittatus Kuhl, 1820) are one of the world’s largest snake species, making them a highly successful and biologically damaging invasive predator in the Greater Everglades Ecosystem, Florida, USA. Though we have knowledge of python diet within this system, we understand very little of other interactions with native species. Effects native species have on invasive...
Authors
Andrea Faye Currylow, Austin Lee Fitzgerald, Matthew T.H. Goetz, Jared L. Draxler, Gretchen Erika Anderson, Matthew McCollister, Christina Romagosa, Amy A. Yackel Adams
Increasing the efficiency and power of camera traps for EDRR & ecological monitoring Increasing the efficiency and power of camera traps for EDRR & ecological monitoring
Invasive species are an ever-growing concern for Florida, especially in important environments like the Greater Everglades Ecosystem. One of the best ways to fight back against invasives is the use of the “Early Detection, Rapid Response” (EDRR) system. The earlier we can detect the presence of a nonnative species, and the faster we respond, the better our chance of stopping its spread...
Authors
Gretchen Erika Anderson, Amy A. Yackel Adams
Egg retention in wild-caught Python bivittatus in the Greater Everglades Ecosystem, Florida, USA Egg retention in wild-caught Python bivittatus in the Greater Everglades Ecosystem, Florida, USA
Retention of eggs in oviducts beyond the normal oviposition period is a common problem for captive reptiles, but the occurrence of egg retention in wild populations is largely unknown. The Burmese python (Python [molurus] bivittatus; Kühl 1820) is an oviparous snake native to south-eastern Asia that is now established in southern Florida. From 2011–2019, invasive Burmese pythons were
Authors
Gretchen Erika Anderson, Frank N. Ridgley, Jillian Maureen Josimovich, Robert Reed, Bryan G. Falk, Amy A. Yackel Adams, Andrea Faye Currylow
Face-off: Novel depredation and nest defense behaviors between an invasive and a native predator in the Greater Everglades Ecosystem, Florida, USA Face-off: Novel depredation and nest defense behaviors between an invasive and a native predator in the Greater Everglades Ecosystem, Florida, USA
We describe several photo-documented novel interactions between intraguild predators in southern Florida—the native bobcat (Lynx rufus) and the invasive Burmese python (Python bivittatus). Over several days we documented a bobcat's depredation of an unguarded python nest and subsequent python nest defense behavior following the return of both animals to the nest. This is the first...
Authors
Andrea Faye Currylow, Matthew F. McCollister, Gretchen Erika Anderson, Jillian Maureen Josimovich, Austin Lee Fitzgerald, Christina M. Romagosa, Amy A. Yackel Adams
Science and Products
Biology, Impacts and Control of Invasive Reptiles in the Everglades
Invasive species are considered to be second only to habitat degradation in terms of negative impacts on the Earth’s ecosystems, and our scientists make up a significant proportion of the global expertise in the rapidly-growing problem of invasive reptiles.
Ecology and Control of Invasive Reptiles in Florida
This project involves development of tools for the detection and control of invasive reptiles in Florida, with an emphasis on pythons and tegu lizards. The goals are to reduce the risk of reptile invasions, investigate early detection methods, maintain rapid response capacity, and understand invasive reptile population biology and ecology to inform management options.
USGS Everglades Research Office - Florida
The Daniel Beard Center in Everglades National Park provides the base for most of the field work done on the control of invasive reptiles by USGS Fort Collins Science Center staff. The team works in Everglades National Park, Big Cypress National Preserve, Crocodile Lake National Wildlife Refuge, and other parts of the Greater Everglades Ecosystem focusing on, among other species of concern...
Photographic sequence of brooding Burmese python (Python bivittatus) and associated temperature of record-sized nest in Big Cypress National Preserve, FL, June to August 2022 Photographic sequence of brooding Burmese python (Python bivittatus) and associated temperature of record-sized nest in Big Cypress National Preserve, FL, June to August 2022
Select photographic sequence of a Burmese Python (Python bivittatus) nesting in the wild within a concrete pipe from 01 June 2022 through 01 August 2022 in Big Cypress National Preserve within the Greater Everglades Ecosystem, Florida, USA. This python was tracked to an area of abandoned construction pipes and discovered inside to have oviposited. Throughout incubation, the python was...
Photo-documented sequences from 01 Jun 2021 - 30 Aug 2021 showing novel interactions between intraguild predators in southern Florida, USA, bobcat and Burmese python Photo-documented sequences from 01 Jun 2021 - 30 Aug 2021 showing novel interactions between intraguild predators in southern Florida, USA, bobcat and Burmese python
Entire photo-documented sequence from 01 June 2021-09 September 2021, including novel interactions between intraguild predators in southern Florida - the native bobcat (Lynx rufus) and the invasive Burmese python (Python bivittatus). A bobcat depredated an unguarded Burmese python nest and subsequently the python exhibited nest defense behavior following the return of both animals to the...
Filter Total Items: 13
Coelomic foreign bodies in wild-caught Python spp. in the Greater Everglades Ecosystem, Florida, USA Coelomic foreign bodies in wild-caught Python spp. in the Greater Everglades Ecosystem, Florida, USA
Burmese pythons (Python molurus bivittatus) and African rock pythons (Python sebae) have established invasive populations in southern Florida, severely disrupting local ecosystems. We analysed necropsy data from 2,179 pythons captured between 2006 and 2022, revealing nine cases of coelomic foreign bodies, primarily consisting of bird beaks, which presumably entered the coelom following
Authors
Gretchen E. Anderson, McKayla M. Spencer, Ray W. Snow, Andrea Currylow, Frank N. Ridgley, Bryan G. Falk, Amy A. Yackel Adams
Wild Burmese python nest site selection, thermogenesis, and brooding behaviors in the Greater Everglades Ecosystem Wild Burmese python nest site selection, thermogenesis, and brooding behaviors in the Greater Everglades Ecosystem
Invasive Burmese pythons (Python bivittatus) are extremely cryptic animals. Although their conservation status in their native range is Vulnerable, in the Greater Everglades Ecosystem (Florida, USA) they have become a dominant destructive force and usually are immediately removed whenever found. This poses a paradox where removals are occurring, yet the study and understanding of python...
Authors
Andrea Faye Currylow, Lisa Marie McBride, Gretchen Erika Anderson, Jacquelyn C. Guzy, Matthew F. McCollister, Christina M. Romagosa, Kristen Hart, Amy A. Yackel Adams
Double take: Ingestion of two rats by a juvenile Burmese Python (Python bivittatus) in Big Cypress National Preserve, FL, USA Double take: Ingestion of two rats by a juvenile Burmese Python (Python bivittatus) in Big Cypress National Preserve, FL, USA
No abstract available.
Authors
Teah M. Evers, Andrea F. Currylow, Mark Robert Sandfoss, Lisa Marie McBride, Christina M. Romagosa, Wesley W. Boone, Jacquelyn C. Guzy, Gretchen Erika Anderson, Kristen Hart, Matthew McCollister, Amy A. Yackel Adams
Flooding-induced failure of an invasive Burmese Python nest in southern Florida Flooding-induced failure of an invasive Burmese Python nest in southern Florida
It is important to understand the factors affecting the reproductive success of an invasive species to estimate population size and develop management plans. There remains much we do not understand about the reproductive biology of invasive Burmese Pythons in both their native and invasive range. Oviposition site selection is an important factor in determining reproductive success as...
Authors
Mark Robert Sandfoss, Lisa Marie McBride, Gretchen Erika Anderson, Amanda Marie Kissel, Matthew McCollister, Christina M. Romagosa, Amy A. Yackel Adams
See a snake, save a snake: Use of external tags to prevent mortality in pythons used in research. See a snake, save a snake: Use of external tags to prevent mortality in pythons used in research.
No abstract available.
Authors
Gretchen Erika Anderson, Lisa Marie McBride, Mark Robert Sandfoss, Amy A. Yackel Adams
Florida Kingsnake (Lampropeltis floridana) consumes a juvenile Burmese Python (Python molurus bivitattus) in southern Florida Florida Kingsnake (Lampropeltis floridana) consumes a juvenile Burmese Python (Python molurus bivitattus) in southern Florida
The Burmese python (Python molurus bivittatus) is an invasive constrictor established across southern Florida. These snakes are dietary generalists with large home ranges and broad habitat requirements and their introduction has had severe impacts on native species and ecosystems in the region. We describe the first observation of a Florida kingsnake (Lampropeltis floridana) that...
Authors
Peter F. Crawford, Jose A. Torres, Jacquelyn C. Guzy, Andrea Faye Currylow, Lisa Marie McBride, Gretchen Erika Anderson, Matthew F. McCollister, Christina M. Romagosa, Amy A. Yackel Adams, Kristen Hart
Testicular abnormalities in the invasive Argentine Black-and-White Tegu lizard (Salvator merianae) in the Florida Everglades Testicular abnormalities in the invasive Argentine Black-and-White Tegu lizard (Salvator merianae) in the Florida Everglades
No abstract available.
Authors
Kyra Woytek, Gretchen Erika Anderson, Kevin Donmoyer, Frank Ridgley, Christina Romagosa, Amy A. Yackel Adams, Andrea Faye Currylow
Maximum clutch size of an invasive Burmese Python (Python bivittatus) in Florida, USA Maximum clutch size of an invasive Burmese Python (Python bivittatus) in Florida, USA
Native to southeastern Asia, the Burmese Python (Python bivittatus Kuhl 1820) is an invasive species established in southern Florida (Snow et al. 2007; Krysko et al. 2016; Krysko et al. 2019). Pythons are documented as having negative effects on the Greater Everglades Ecosystem and they have proven to be a complex problem for managers trying to control populations (Guzy et al. 2023)...
Authors
Andrea Faye Currylow, Teah Evers, Gretchen Erika Anderson, Lisa Marie McBride, Matthew McCollister, Jacquelyn C. Guzy, Christina Romagosa, Kristen Hart, Amy A. Yackel Adams
Natives bite back: Depredation and mortality of invasive juvenile Burmese pythons (Python bivittatus) in the Greater Everglades Ecosystem Natives bite back: Depredation and mortality of invasive juvenile Burmese pythons (Python bivittatus) in the Greater Everglades Ecosystem
Burmese pythons (Python bivittatus Kuhl, 1820) are one of the world’s largest snake species, making them a highly successful and biologically damaging invasive predator in the Greater Everglades Ecosystem, Florida, USA. Though we have knowledge of python diet within this system, we understand very little of other interactions with native species. Effects native species have on invasive...
Authors
Andrea Faye Currylow, Austin Lee Fitzgerald, Matthew T.H. Goetz, Jared L. Draxler, Gretchen Erika Anderson, Matthew McCollister, Christina Romagosa, Amy A. Yackel Adams
Increasing the efficiency and power of camera traps for EDRR & ecological monitoring Increasing the efficiency and power of camera traps for EDRR & ecological monitoring
Invasive species are an ever-growing concern for Florida, especially in important environments like the Greater Everglades Ecosystem. One of the best ways to fight back against invasives is the use of the “Early Detection, Rapid Response” (EDRR) system. The earlier we can detect the presence of a nonnative species, and the faster we respond, the better our chance of stopping its spread...
Authors
Gretchen Erika Anderson, Amy A. Yackel Adams
Egg retention in wild-caught Python bivittatus in the Greater Everglades Ecosystem, Florida, USA Egg retention in wild-caught Python bivittatus in the Greater Everglades Ecosystem, Florida, USA
Retention of eggs in oviducts beyond the normal oviposition period is a common problem for captive reptiles, but the occurrence of egg retention in wild populations is largely unknown. The Burmese python (Python [molurus] bivittatus; Kühl 1820) is an oviparous snake native to south-eastern Asia that is now established in southern Florida. From 2011–2019, invasive Burmese pythons were
Authors
Gretchen Erika Anderson, Frank N. Ridgley, Jillian Maureen Josimovich, Robert Reed, Bryan G. Falk, Amy A. Yackel Adams, Andrea Faye Currylow
Face-off: Novel depredation and nest defense behaviors between an invasive and a native predator in the Greater Everglades Ecosystem, Florida, USA Face-off: Novel depredation and nest defense behaviors between an invasive and a native predator in the Greater Everglades Ecosystem, Florida, USA
We describe several photo-documented novel interactions between intraguild predators in southern Florida—the native bobcat (Lynx rufus) and the invasive Burmese python (Python bivittatus). Over several days we documented a bobcat's depredation of an unguarded python nest and subsequent python nest defense behavior following the return of both animals to the nest. This is the first...
Authors
Andrea Faye Currylow, Matthew F. McCollister, Gretchen Erika Anderson, Jillian Maureen Josimovich, Austin Lee Fitzgerald, Christina M. Romagosa, Amy A. Yackel Adams