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Gretchen Anderson, MSc (Former Employee)

Science and Products

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A Burmese python coiled in the grass in the Everglades.

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.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Fort Collins Science Center
link

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.
Learn More
link
Student Intern Alejandro Grajal-Puche holds an Argentine black and white tegu lizard.

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.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Fort Collins Science Center
link

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.
Learn More
link
Everglades National Park

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...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Land Management Research Program, Fort Collins Science Center
link

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...
Learn More

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 nest. Fir
By
Fort Collins Science Center

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
By
Ecosystems Mission Area, Fort Collins Science Center

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 nesting is a
Authors
Mark Robert Sandfoss, Lisa Marie McBride, Gretchen Erika Anderson, Amanda Marie Kissel, Matthew McCollister, Christina M. Romagosa, Amy A. Yackel Adams
By
Ecosystems Mission Area, Fort Collins Science Center

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 consumed a hatchl
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
By
Ecosystems Mission Area, Fort Collins Science Center, Wetland and Aquatic Research Center

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
By
Ecosystems Mission Area, Fort Collins Science Center

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). This species
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
By
Ecosystems Mission Area, Fort Collins Science Center, Wetland and Aquatic Research Center

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 pythons, es
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
By
Ecosystems Mission Area, Fort Collins Science Center

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. For years,
Authors
Gretchen Erika Anderson, Amy A. Yackel Adams
By
Ecosystems Mission Area, Fort Collins Science Center

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 opportunistic
Authors
Gretchen Erika Anderson, Frank N. Ridgley, Jillian Maureen Josimovich, Robert Reed, Bryan G. Falk, Amy A. Yackel Adams, Andrea Faye Currylow
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

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 documentation of
Authors
Andrea Faye Currylow, Matthew F. McCollister, Gretchen Erika Anderson, Jillian Maureen Josimovich, Austin Lee Fitzgerald, Christina M. Romagosa, Amy A. Yackel Adams
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

Agkistrodon conanti (Florida Cottonmouth) and Python bivittatus (Burmese Python). Diet and Predation

Python bivittatus is established in the Greater Everglades Ecosystem in southern Florida, USA. Documented predators on pythons in Florida include Alligator mississippiensis (American Alligator; Snow et al. 2006. Herpetol. Rev. 37:81–81), Drymarchon couperi (Gulf Coast Indigo Snake; Andreadis et al. 2018. Herpetol. Rev. 49:341–342), Lynx rufus (Bobcat; McCollister et al. 2021. Southeast. Nat. 20:N5
Authors
Ian A. Bartoszek, Gretchen Erika Anderson, Ian Easterling, Jillian Maureen Josimovich, Alex Furst, Frank N. Ridgley, Austin Lee Fitzgerald, Amy A. Yackel Adams, Andrea Faye Currylow
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

Science and Products

link
A Burmese python coiled in the grass in the Everglades.

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.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Fort Collins Science Center
link

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.
Learn More
link
Student Intern Alejandro Grajal-Puche holds an Argentine black and white tegu lizard.

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.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Fort Collins Science Center
link

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.
Learn More
link
Everglades National Park

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...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Land Management Research Program, Fort Collins Science Center
link

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...
Learn More

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 nest. Fir
By
Fort Collins Science Center

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
By
Ecosystems Mission Area, Fort Collins Science Center

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 nesting is a
Authors
Mark Robert Sandfoss, Lisa Marie McBride, Gretchen Erika Anderson, Amanda Marie Kissel, Matthew McCollister, Christina M. Romagosa, Amy A. Yackel Adams
By
Ecosystems Mission Area, Fort Collins Science Center

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 consumed a hatchl
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
By
Ecosystems Mission Area, Fort Collins Science Center, Wetland and Aquatic Research Center

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
By
Ecosystems Mission Area, Fort Collins Science Center

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). This species
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
By
Ecosystems Mission Area, Fort Collins Science Center, Wetland and Aquatic Research Center

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 pythons, es
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
By
Ecosystems Mission Area, Fort Collins Science Center

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. For years,
Authors
Gretchen Erika Anderson, Amy A. Yackel Adams
By
Ecosystems Mission Area, Fort Collins Science Center

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 opportunistic
Authors
Gretchen Erika Anderson, Frank N. Ridgley, Jillian Maureen Josimovich, Robert Reed, Bryan G. Falk, Amy A. Yackel Adams, Andrea Faye Currylow
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

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 documentation of
Authors
Andrea Faye Currylow, Matthew F. McCollister, Gretchen Erika Anderson, Jillian Maureen Josimovich, Austin Lee Fitzgerald, Christina M. Romagosa, Amy A. Yackel Adams
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

Agkistrodon conanti (Florida Cottonmouth) and Python bivittatus (Burmese Python). Diet and Predation

Python bivittatus is established in the Greater Everglades Ecosystem in southern Florida, USA. Documented predators on pythons in Florida include Alligator mississippiensis (American Alligator; Snow et al. 2006. Herpetol. Rev. 37:81–81), Drymarchon couperi (Gulf Coast Indigo Snake; Andreadis et al. 2018. Herpetol. Rev. 49:341–342), Lynx rufus (Bobcat; McCollister et al. 2021. Southeast. Nat. 20:N5
Authors
Ian A. Bartoszek, Gretchen Erika Anderson, Ian Easterling, Jillian Maureen Josimovich, Alex Furst, Frank N. Ridgley, Austin Lee Fitzgerald, Amy A. Yackel Adams, Andrea Faye Currylow
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center
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