Michael Cherkiss
Michael Cherkiss' research interests include population ecology and conservation of amphibians and reptiles, with experience extending to radio telemetry and transmitter attachment on pythons, crocodilians, sea turtles and other species.
BACKGROUND
Prior to joining the USGS, Cherkiss was a biologist with the University of Florida for over ten years. He has over 15 years’ experience conducting research in the coastal areas of South Florida, Everglades ecosystems and internationally throughout the Caribbean, Central and South American.
Education and Certifications
M.S., Wildlife Ecology and Conservation, University of Florida, 2000
B.S., Wildlife Ecology and Conservation, University of Florida, 1996
Science and Products
Developing Future Habitat Condition Scenarios for Wildlife in the Imperiled Pine Rockland Ecosystem of South Florida
The pine rockland ecosystem is found only in south Florida and the Bahamas and provides important habitat for numerous rare and endemic plants and animals. These include 18 species that are already federally listed as threatened or endangered and four other species petitioned for listing that are scheduled for development of Species Status Assessments (SSAs). Today, south Florida’s pine rockland e
Evaluation of Tegu Movements and Habitat Use in Relation to Location and Habitat
Tegus are breeding, they have a diverse diet, and they are established in areas throughout South Florida. USGS is tracking this problematic reptile species to better understand their movements and habitat use to help managers prevent dispersal into new areas.
Spatial Ecology of the American Crocodile (Crocodylus acutus) and American Alligator (Alligator mississippiensis) in the Greater Everglades
Satellite/GPS tags help USGS researchers understand the movements of American Alligators and American Crocodiles in the Greater Everglades.
Stable isotope values for Dry Tortugas nesting loggerheads sampled 2013-2018
We used a combination of stable isotope analysis of carbon and nitrogen values in nesting loggerhead sea turtle samples to describe the foraging area used by each turtle. Here we present the stable isotope values for United States Geological Survey (USGS) turtles sampled in the remote Dry Tortugas National Park, south Florida, and their assigned foraging area.
Satellite tracking of sea turtles using Biscayne National Park, 2009-2021
This dataset includes details of loggerhead and green turtles captured and satellite tagged between 2009 and 2021; the turtles presented here have tracking days within Biscayne National Park. A subset of turtles was captured within Biscayne National Park, whereas others were tracked to the study site, and tagged elsewhere. The dataset contains information related to satellite tracking (e.g., track
Diet of invasive Burmese Pythons (Python molorus bivittatus) in southern Florida, 1995-2020
Digestive tract contents were identified to provide an account of Burmese python diet. Diet contents came from 1716 pythons collected by cooperators during 1995-2020 from public and private lands across southern Florida, primarily within the Greater Everglades Ecosystem. Burmese pythons consumed 76 species of fauna across three taxonomic classes (Aves, Mammalia, and Reptilia).
Size distribution and reproductive data of the invasive Burmese python (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida, USA, 1995-2021
This dataset contains morphometric information from Burmese pythons collected from an invasive population in southern Florida between 1995-2021. Scientists from the U.S. Geological Survey and the National Park Service curated this dataset as a repository for records of Burmese pythons found on or nearby federal lands in southern Florida, including Everglades National Park, Big Cypress National Pre
Tracking durations for marine turtles satellite tagged in Gulf of Mexico and Caribbean sites, 2008-2019
This dataset contains tracking durations for several species of sea turtles tagged with satellite tags between 2008 and 2019. It contains information on species, turtle size, capture methods, tag type, how many days each tag transmitted, whether or not the tag was still attached upon recapture, fouling 'status' of the tag, and foraging region. This dataset thus allows estimation of tracking durati
Burmese python acceleration and location data, Everglades National Park, 2010 - 2012
The dataset contains 3 components: (1) acceleration data logger (ADL) data, (2) GPS location data, and (3) body temperature data. We have ADL data from pythons in captivity (N = 2) and in free-ranging snakes (N=4). We have GPS data for 3 out of 4 free-ranging snakes. We have body temperature data for all 4 free-ranging snakes.
Hatch dates of American crocodile nests in Everglades National Park and Turkey Point Power Plant 1983-2016
We monitored nests from 1983 to 2016 during the crocodile nesting season (April through August) as part of a long-term American crocodile monitoring programs within Everglades National Park (ENP; since 1978) and Turkey Point Power Plant (TP; since 1983). Nests were located during April and May (egg laying period) and monitored from June to August (hatching period). During the hatching period, surv
Filter Total Items: 48
Nerodia clarkii (Saltmarsh Watersnake). Predation
Predators of Nerodia clarkii are suspected to include larger species of crabs, fish, wading birds, snakes, alligators, and crocodiles. To our knowledge, there have only been two published observations of predation on N. clarkii, including a predation attempt from a Callinectes sapidus (Blue Crab) in Mississippi, USA and a successful predation by a Grus americana (Whooping Crane) in Texas, USA. Her
Authors
Bryna L. Daykin, Sidney T. Godfrey, Michael Cherkiss, Gareth Blakemore, Frank J. Mazzotti
Satellite tracking reveals use of Biscayne National Park by sea turtles tagged in multiple locations
Although historical observations date back to the 1800’s, there is little information on sea turtle occupancy within Biscayne National Park (BNP). The park is located along the Florida reef tract and is dominated by the Gulfstream, which acts as a corridor for many marine animals. Here we used satellite telemetry to determine areas of use in BNP for two species of imperiled sea turtles, loggerhead
Authors
Kristen Hart, Allison Benscoter, Haley M. Turner, Michael Cherkiss, Andrew Crowder, Jacquelyn C. Guzy, David Roche, Christopher R. Sasso, Glenn D. Goodwin, Derek A. Burkholder
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 f
Authors
Jacquelyn C. Guzy, Bryan G. Falk, Brian J. Smith, John David Willson, Robert Reed, Nicholas Aumen, Michael L. Avery, Ian A. Bartoszek, Earl Campbell, Michael Cherkiss, Natalie M. Claunch, Andrea Faye Currylow, Tylan Dean, Jeremy Dixon, Richard M. Engeman, Sarah Funck, Rebekah Gibble, Kodiak C. Hengstebeck, John S. Humphrey, Margaret Hunter, Jillian Josimovich, Jennifer Ketterlin Eckles, Michael Kirkland, Frank J. Mazzotti, Robert A. McCleery, Melissa A. Miller, Matthew F. McCollister, M. Rockwell Parker, Shannon E. Pittman, Michael R. Rochford, Christina Romagosa, Art Roybal, Ray W. Snow, McKayla M. Spencer, Hardin Waddle, Amy A. Yackel Adams, Kristen Hart
Crocodylus acutus (American crocodile). Diet
Reported prey items of Crocodylus acutus include insects, crustaceans, fish, and large reptiles (Medem 1981. Los Crocodylia de Sur America. Volumen I. Los Crocodylia de Colombia. Colciencias. Bogota, Colombia. 398 pp.; Platt et al. 2002. Herpetol. Rev. 33:202–203; Platt et al. 2013. J. Herpetol. 47:1–10; Balaguera-Reina et al. 2018. Ecosphere 9:e02393). Recently, new potential prey items such as L
Authors
Sidney T. Godfrey, Michael Cherkiss, Jeffrey S. Beauchamp, Michiko A. Squires, Frank J. Mazzotti, Lindsey Hord, William Billings
Size distribution and reproductive phenology of the invasive Burmese python (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida, USA
The design of successful invasive species control programs is often hindered by the absence of basic demographic data on the targeted population. Establishment of invasive Burmese pythons (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida USA has led to local precipitous declines (> 90%) of mesomammal populations and is also a major threat to native populations of reptiles an
Authors
Andrea Faye Currylow, Bryan Falk, Amy A. Yackel Adams, Christina M. Romagosa, Jillian Josimovich, Michael R. Rochford, Michael Cherkiss, Melia Gail Nafus, Kristen Hart, Frank J. Mazzotti, Ray W. Snow, Robert Reed
Natural and anthropogenic factors influencing nesting ecology of the American crocodile in Florida, United States
Nesting ecology of American crocodiles (Crocodylus acutus) in Florida has been both positively and negatively influenced by anthropogenic and natural factors since the species was placed on the federally endangered species list in 1975. This includes a shift in nesting sites and an expansion of nesting to anthropogenic habitat. Using a 50-year record of monitoring data (1970-2020), we assessed fac
Authors
Frank J. Mazzotti, Sergio A. Balaguera-Reina, Laura A. Brandt, Venetia Briggs-Gonzalez, Michael Cherkiss, Seth C Farris, Avishka Godahewa
Stable isotopes used to infer trophic position of green turtles (Chelonia mydas) from Dry Tortugas National Park, Gulf of Mexico, United States
Evaluating resource use patterns for imperiled species is critical for understanding what supports their populations. Here we established stable isotope (δ13C, δ15N) values for the endangered green sea turtle (Chelonia mydas) population found within the boundaries of Dry Tortugas National Park (DRTO), south Florida, USA. There is little gene flow between turtles sampled at DRTO and in other rooker
Authors
David Roche, Michael Cherkiss, Brian J. Smith, Derek A. Burkholder, Kristen Hart
American crocodiles (Crocodylus acutus) as restoration bioindicators in the Florida Everglades
The federally threatened American crocodile (Crocodylus acutus) is a flagship species and ecological indicator of hydrologic restoration in the Florida Everglades. We conducted a long-term capture-recapture study on the South Florida population of American crocodiles from 1978 to 2015 to evaluate the effects of restoration efforts to more historic hydrologic conditions. The study produced 10,040 c
Authors
Venetia S. Briggs-Gonzalez, Mathieu Basille, Michael Cherkiss, Frank J. Mazzotti
Accelerometry to study fine-scale activity of invasive Burmese pythons (Python bivittatus) in the wild
The establishment of Burmese pythons (Python bivittatus) in Everglades National Park, Florida, USA, has been connected to a > 90% decline in the mesomammal population in the park and is a major threat to native reptile and bird populations. Efforts to control this population are underway, but are hampered by a lack of information about fine-scale activity cycles and ecology of these cryptic animal
Authors
Nicholas M. Whitney, Connor F. White, Brian Smith, Michael Cherkiss, Frank J. Mazzotti, Kristen Hart
Space use and relative habitat selection for immature green turtles within a Caribbean marine protected area
Background
A better understanding of sea turtle spatial ecology is critical for the continued conservation of imperiled sea turtles and their habitats. For resource managers to develop the most effective conservation strategies, it is especially important to examine how turtles use and select for habitats within their developmental foraging grounds. Here, we examine the space use and relative habi
Authors
Lucas P Griffin, Brian J. Smith, Michael Cherkiss, Andrew Crowder, Clayton G Pollock, Zandy Hillis-Starr, Andy J. Danylchuk, Kristen Hart
Shifts in hatching date of American crocodile (Crocodylus acutus) in southern Florida
Globally temperature of marine environments is on the rise and temperature plays an important role in the life-history of reptiles. In this study, we examined the relationship between sea surface temperature and average date of hatching for American crocodiles (Crocodylus acutus) over a 37-year period at two nesting sites, Everglades National Park and Florida Power and Light Turkey Point Power Pla
Authors
Michael Cherkiss, James I. Watling, Laura A. Brandt, Frank J. Mazzotti, Jim Linsay, Jeffrey S. Beauchamp, Jerome J. Lorenz, Joseph Wasilewski, Ikuko Fujisaki, Kristen Hart
Acoustic tag retention rate varies between juvenile green and hawksbill sea turtles
Background
Biotelemetry has become a key tool for studying marine animals in the last decade, and a wide range of electronic tags are now available for answering a range of research questions. However, comparatively, less attention has been given to attachment methods for these tags and the implications of tag retention on study design, especially when designing a comparative study looking at mult
Authors
Thomas Selby, Brian Smith, Michael Cherkiss, Andrew Crowder, Zandy Hillis-Starr, Clayton Pollock, Kristen Hart
Science and Products
Developing Future Habitat Condition Scenarios for Wildlife in the Imperiled Pine Rockland Ecosystem of South Florida
The pine rockland ecosystem is found only in south Florida and the Bahamas and provides important habitat for numerous rare and endemic plants and animals. These include 18 species that are already federally listed as threatened or endangered and four other species petitioned for listing that are scheduled for development of Species Status Assessments (SSAs). Today, south Florida’s pine rockland e
Evaluation of Tegu Movements and Habitat Use in Relation to Location and Habitat
Tegus are breeding, they have a diverse diet, and they are established in areas throughout South Florida. USGS is tracking this problematic reptile species to better understand their movements and habitat use to help managers prevent dispersal into new areas.
Spatial Ecology of the American Crocodile (Crocodylus acutus) and American Alligator (Alligator mississippiensis) in the Greater Everglades
Satellite/GPS tags help USGS researchers understand the movements of American Alligators and American Crocodiles in the Greater Everglades.
Stable isotope values for Dry Tortugas nesting loggerheads sampled 2013-2018
We used a combination of stable isotope analysis of carbon and nitrogen values in nesting loggerhead sea turtle samples to describe the foraging area used by each turtle. Here we present the stable isotope values for United States Geological Survey (USGS) turtles sampled in the remote Dry Tortugas National Park, south Florida, and their assigned foraging area.
Satellite tracking of sea turtles using Biscayne National Park, 2009-2021
This dataset includes details of loggerhead and green turtles captured and satellite tagged between 2009 and 2021; the turtles presented here have tracking days within Biscayne National Park. A subset of turtles was captured within Biscayne National Park, whereas others were tracked to the study site, and tagged elsewhere. The dataset contains information related to satellite tracking (e.g., track
Diet of invasive Burmese Pythons (Python molorus bivittatus) in southern Florida, 1995-2020
Digestive tract contents were identified to provide an account of Burmese python diet. Diet contents came from 1716 pythons collected by cooperators during 1995-2020 from public and private lands across southern Florida, primarily within the Greater Everglades Ecosystem. Burmese pythons consumed 76 species of fauna across three taxonomic classes (Aves, Mammalia, and Reptilia).
Size distribution and reproductive data of the invasive Burmese python (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida, USA, 1995-2021
This dataset contains morphometric information from Burmese pythons collected from an invasive population in southern Florida between 1995-2021. Scientists from the U.S. Geological Survey and the National Park Service curated this dataset as a repository for records of Burmese pythons found on or nearby federal lands in southern Florida, including Everglades National Park, Big Cypress National Pre
Tracking durations for marine turtles satellite tagged in Gulf of Mexico and Caribbean sites, 2008-2019
This dataset contains tracking durations for several species of sea turtles tagged with satellite tags between 2008 and 2019. It contains information on species, turtle size, capture methods, tag type, how many days each tag transmitted, whether or not the tag was still attached upon recapture, fouling 'status' of the tag, and foraging region. This dataset thus allows estimation of tracking durati
Burmese python acceleration and location data, Everglades National Park, 2010 - 2012
The dataset contains 3 components: (1) acceleration data logger (ADL) data, (2) GPS location data, and (3) body temperature data. We have ADL data from pythons in captivity (N = 2) and in free-ranging snakes (N=4). We have GPS data for 3 out of 4 free-ranging snakes. We have body temperature data for all 4 free-ranging snakes.
Hatch dates of American crocodile nests in Everglades National Park and Turkey Point Power Plant 1983-2016
We monitored nests from 1983 to 2016 during the crocodile nesting season (April through August) as part of a long-term American crocodile monitoring programs within Everglades National Park (ENP; since 1978) and Turkey Point Power Plant (TP; since 1983). Nests were located during April and May (egg laying period) and monitored from June to August (hatching period). During the hatching period, surv
Filter Total Items: 48
Nerodia clarkii (Saltmarsh Watersnake). Predation
Predators of Nerodia clarkii are suspected to include larger species of crabs, fish, wading birds, snakes, alligators, and crocodiles. To our knowledge, there have only been two published observations of predation on N. clarkii, including a predation attempt from a Callinectes sapidus (Blue Crab) in Mississippi, USA and a successful predation by a Grus americana (Whooping Crane) in Texas, USA. Her
Authors
Bryna L. Daykin, Sidney T. Godfrey, Michael Cherkiss, Gareth Blakemore, Frank J. Mazzotti
Satellite tracking reveals use of Biscayne National Park by sea turtles tagged in multiple locations
Although historical observations date back to the 1800’s, there is little information on sea turtle occupancy within Biscayne National Park (BNP). The park is located along the Florida reef tract and is dominated by the Gulfstream, which acts as a corridor for many marine animals. Here we used satellite telemetry to determine areas of use in BNP for two species of imperiled sea turtles, loggerhead
Authors
Kristen Hart, Allison Benscoter, Haley M. Turner, Michael Cherkiss, Andrew Crowder, Jacquelyn C. Guzy, David Roche, Christopher R. Sasso, Glenn D. Goodwin, Derek A. Burkholder
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 f
Authors
Jacquelyn C. Guzy, Bryan G. Falk, Brian J. Smith, John David Willson, Robert Reed, Nicholas Aumen, Michael L. Avery, Ian A. Bartoszek, Earl Campbell, Michael Cherkiss, Natalie M. Claunch, Andrea Faye Currylow, Tylan Dean, Jeremy Dixon, Richard M. Engeman, Sarah Funck, Rebekah Gibble, Kodiak C. Hengstebeck, John S. Humphrey, Margaret Hunter, Jillian Josimovich, Jennifer Ketterlin Eckles, Michael Kirkland, Frank J. Mazzotti, Robert A. McCleery, Melissa A. Miller, Matthew F. McCollister, M. Rockwell Parker, Shannon E. Pittman, Michael R. Rochford, Christina Romagosa, Art Roybal, Ray W. Snow, McKayla M. Spencer, Hardin Waddle, Amy A. Yackel Adams, Kristen Hart
Crocodylus acutus (American crocodile). Diet
Reported prey items of Crocodylus acutus include insects, crustaceans, fish, and large reptiles (Medem 1981. Los Crocodylia de Sur America. Volumen I. Los Crocodylia de Colombia. Colciencias. Bogota, Colombia. 398 pp.; Platt et al. 2002. Herpetol. Rev. 33:202–203; Platt et al. 2013. J. Herpetol. 47:1–10; Balaguera-Reina et al. 2018. Ecosphere 9:e02393). Recently, new potential prey items such as L
Authors
Sidney T. Godfrey, Michael Cherkiss, Jeffrey S. Beauchamp, Michiko A. Squires, Frank J. Mazzotti, Lindsey Hord, William Billings
Size distribution and reproductive phenology of the invasive Burmese python (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida, USA
The design of successful invasive species control programs is often hindered by the absence of basic demographic data on the targeted population. Establishment of invasive Burmese pythons (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida USA has led to local precipitous declines (> 90%) of mesomammal populations and is also a major threat to native populations of reptiles an
Authors
Andrea Faye Currylow, Bryan Falk, Amy A. Yackel Adams, Christina M. Romagosa, Jillian Josimovich, Michael R. Rochford, Michael Cherkiss, Melia Gail Nafus, Kristen Hart, Frank J. Mazzotti, Ray W. Snow, Robert Reed
Natural and anthropogenic factors influencing nesting ecology of the American crocodile in Florida, United States
Nesting ecology of American crocodiles (Crocodylus acutus) in Florida has been both positively and negatively influenced by anthropogenic and natural factors since the species was placed on the federally endangered species list in 1975. This includes a shift in nesting sites and an expansion of nesting to anthropogenic habitat. Using a 50-year record of monitoring data (1970-2020), we assessed fac
Authors
Frank J. Mazzotti, Sergio A. Balaguera-Reina, Laura A. Brandt, Venetia Briggs-Gonzalez, Michael Cherkiss, Seth C Farris, Avishka Godahewa
Stable isotopes used to infer trophic position of green turtles (Chelonia mydas) from Dry Tortugas National Park, Gulf of Mexico, United States
Evaluating resource use patterns for imperiled species is critical for understanding what supports their populations. Here we established stable isotope (δ13C, δ15N) values for the endangered green sea turtle (Chelonia mydas) population found within the boundaries of Dry Tortugas National Park (DRTO), south Florida, USA. There is little gene flow between turtles sampled at DRTO and in other rooker
Authors
David Roche, Michael Cherkiss, Brian J. Smith, Derek A. Burkholder, Kristen Hart
American crocodiles (Crocodylus acutus) as restoration bioindicators in the Florida Everglades
The federally threatened American crocodile (Crocodylus acutus) is a flagship species and ecological indicator of hydrologic restoration in the Florida Everglades. We conducted a long-term capture-recapture study on the South Florida population of American crocodiles from 1978 to 2015 to evaluate the effects of restoration efforts to more historic hydrologic conditions. The study produced 10,040 c
Authors
Venetia S. Briggs-Gonzalez, Mathieu Basille, Michael Cherkiss, Frank J. Mazzotti
Accelerometry to study fine-scale activity of invasive Burmese pythons (Python bivittatus) in the wild
The establishment of Burmese pythons (Python bivittatus) in Everglades National Park, Florida, USA, has been connected to a > 90% decline in the mesomammal population in the park and is a major threat to native reptile and bird populations. Efforts to control this population are underway, but are hampered by a lack of information about fine-scale activity cycles and ecology of these cryptic animal
Authors
Nicholas M. Whitney, Connor F. White, Brian Smith, Michael Cherkiss, Frank J. Mazzotti, Kristen Hart
Space use and relative habitat selection for immature green turtles within a Caribbean marine protected area
Background
A better understanding of sea turtle spatial ecology is critical for the continued conservation of imperiled sea turtles and their habitats. For resource managers to develop the most effective conservation strategies, it is especially important to examine how turtles use and select for habitats within their developmental foraging grounds. Here, we examine the space use and relative habi
Authors
Lucas P Griffin, Brian J. Smith, Michael Cherkiss, Andrew Crowder, Clayton G Pollock, Zandy Hillis-Starr, Andy J. Danylchuk, Kristen Hart
Shifts in hatching date of American crocodile (Crocodylus acutus) in southern Florida
Globally temperature of marine environments is on the rise and temperature plays an important role in the life-history of reptiles. In this study, we examined the relationship between sea surface temperature and average date of hatching for American crocodiles (Crocodylus acutus) over a 37-year period at two nesting sites, Everglades National Park and Florida Power and Light Turkey Point Power Pla
Authors
Michael Cherkiss, James I. Watling, Laura A. Brandt, Frank J. Mazzotti, Jim Linsay, Jeffrey S. Beauchamp, Jerome J. Lorenz, Joseph Wasilewski, Ikuko Fujisaki, Kristen Hart
Acoustic tag retention rate varies between juvenile green and hawksbill sea turtles
Background
Biotelemetry has become a key tool for studying marine animals in the last decade, and a wide range of electronic tags are now available for answering a range of research questions. However, comparatively, less attention has been given to attachment methods for these tags and the implications of tag retention on study design, especially when designing a comparative study looking at mult
Authors
Thomas Selby, Brian Smith, Michael Cherkiss, Andrew Crowder, Zandy Hillis-Starr, Clayton Pollock, Kristen Hart