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...
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.
Nesting and non-nesting emergences for four species of imperiled sea turtles derived from acceleration data loggers, 2012-2017 Nesting and non-nesting emergences for four species of imperiled sea turtles derived from acceleration data loggers, 2012-2017
These data contain acceleration, pitch, yaw, roll, and ancillary data collected by acceleration data loggers (ADL) attached to four sea turtle species: green (Chelonia mydas) sea turtles, hawksbill (Eretmochelys imbricata) sea turtles, Kemp's ridley (Lepidochelys kempii) sea turtles, and loggerhead (Caretta caretta) sea turtles. A total of 54 nesting events and 76 non-nesting emergence...
Fine-scale behavior of sea turtles in the Gulf derived from acceleration data loggers, 2018 - 2023 Fine-scale behavior of sea turtles in the Gulf derived from acceleration data loggers, 2018 - 2023
This release contains data from acceleration data logger (ADL) float packages designed to 'pop-off' in a set amount of time for recovery and platform terminal transmitter (PTT) satellite tags attached to 12 Kemp's ridley (Lepidochelys kempii) and 7 Loggerhead (Caretta caretta) turtles in several geographic locations, using the methods of Hart et al., 2013. These instrument packages...
Stable carbon (C13) and nitrogen (N15) isotopic values of American alligators within the Florida Everglades (2013-2020) Stable carbon (C13) and nitrogen (N15) isotopic values of American alligators within the Florida Everglades (2013-2020)
This dataset contains morphometric and isotopic data for American alligators (Alligator mississippiensis) that were sampled from within four freshwater (FW) wetlands and one estuarine (EST) wetland within the Greater Everglades ecosystem. Due to their compartmentalization and varied habitat and water regimes, there were multiple sampling sites within two of the FW wetlands. The five...
Historical sea turtle relocation trawling data in the southeast U.S. (1991 - 2024) Historical sea turtle relocation trawling data in the southeast U.S. (1991 - 2024)
The U.S. Geological Survey (USGS) Wetlands Aquatic Research Center worked alongside the U.S. Army Corps of Engineers (USACE) and Bureau of Ocean Energy Management (BOEM) to amalgamate over three decades of relocation trawling records. It is USACE's mission to provide safe, reliable, efficient , and environmentally sustainable waterborne transportation systems (channels, harbors, and...
Capture histories and body size data for a population of mangrove diamond-backed terrapins (Malaclemys terrapin rhizophorarum) Everglades National Park, Florida, USA, 2001-2019 Capture histories and body size data for a population of mangrove diamond-backed terrapins (Malaclemys terrapin rhizophorarum) Everglades National Park, Florida, USA, 2001-2019
We used an 18-year dataset (2001 to 2019) incorporating year, sex, hurricane occurrence and sampling effort to estimate survival using Cormack–Jolly–Seber (CJS) models in Program Mark. Annual survivorship estimates were high from 2001-2003 for both sexes (91-96%) and variable from 2006-2014 (77-92%). Beginning in 2015 survival estimates exhibited a steeper decline (females: 65%, males 75...
Stable isotope values for Dry Tortugas nesting loggerheads sampled 2013-2018 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.
Filter Total Items: 52
Biologging to identify nesting and non-nesting emergences for four species of imperiled sea turtles Biologging to identify nesting and non-nesting emergences for four species of imperiled sea turtles
Quantifying sea turtle nesting behavior is essential for recovery planning and evaluating management actions. Traditional monitoring approaches, based on nest counts from beach surveys, can misclassify non-nesting emergences, obscure true fecundity, and underestimate clutch frequency, metrics that directly influence population models and regulatory decisions. Here, we demonstrate that...
Authors
Kristen Hart, Connor F. White, Donna J. Shaver, Margaret Lamont, Michael Cherkiss, Andrew G. Crowder, Nicholas M. Whitney
Isotopic niche plasticity of American alligators within the southern Everglades Isotopic niche plasticity of American alligators within the southern Everglades
Hydrologic alterations within the Everglades have degraded American alligator (Alligator mississippiensis) habitat, reduced prey base, and increased physiological stress. Alligator body condition declined across many management areas from 2000 through 2014, prompting us to investigate the relationship between their intraspecific isotopic niche dynamics and body condition. Alligators...
Authors
Mathew Denton, Michael Cherkiss, Frank J. Mazzotti, Laura A. Brandt, Sidney T. Godfrey, Darren Johnson, Kristen Hart
Interpreting a sudden population decline in a long-lived species (Malaclemys terrapin rhizophorarum) Interpreting a sudden population decline in a long-lived species (Malaclemys terrapin rhizophorarum)
Long-term ecological studies are critical for providing insight into population dynamics and detecting population declines, particularly for species of conservation concern. However, spatiotemporal variation and logistical challenges make the identification of sudden population declines difficult. We conducted an in-water capture-mark-recapture study of mangrove diamond-backed terrapins
Authors
Jacquelyn C. Guzy, Brian J. Smith, Mathew Denton, Michael Cherkiss, David Roche, Andrew G. Crowder, Kristen Hart
Not just corticosterone: Further characterization of the endocrine response of Kemp’s ridley sea turtles (Lepidochelys kempii) reveals elevated plasma aldosterone concentrations during field capture events Not just corticosterone: Further characterization of the endocrine response of Kemp’s ridley sea turtles (Lepidochelys kempii) reveals elevated plasma aldosterone concentrations during field capture events
To develop safe and effective management policies, it is important to understand the physiologic effects of fishing interactions and scientific research methods on endangered marine species. In the present study, validated assays for plasma corticosterone, free thyroxine (fT4), and aldosterone were used to assess the endocrine status of 61 presumed healthy, wild Kemp's ridley sea turtles
Authors
Charles J. Innis, Katherine M. Graham, Cody R. Mott, Kristen Hart, David Roche, Michael Cherkiss, Elizabeth A. Burgess
Nerodia clarkii (Saltmarsh Watersnake). Predation 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...
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 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...
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
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...
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.
Nesting and non-nesting emergences for four species of imperiled sea turtles derived from acceleration data loggers, 2012-2017 Nesting and non-nesting emergences for four species of imperiled sea turtles derived from acceleration data loggers, 2012-2017
These data contain acceleration, pitch, yaw, roll, and ancillary data collected by acceleration data loggers (ADL) attached to four sea turtle species: green (Chelonia mydas) sea turtles, hawksbill (Eretmochelys imbricata) sea turtles, Kemp's ridley (Lepidochelys kempii) sea turtles, and loggerhead (Caretta caretta) sea turtles. A total of 54 nesting events and 76 non-nesting emergence...
Fine-scale behavior of sea turtles in the Gulf derived from acceleration data loggers, 2018 - 2023 Fine-scale behavior of sea turtles in the Gulf derived from acceleration data loggers, 2018 - 2023
This release contains data from acceleration data logger (ADL) float packages designed to 'pop-off' in a set amount of time for recovery and platform terminal transmitter (PTT) satellite tags attached to 12 Kemp's ridley (Lepidochelys kempii) and 7 Loggerhead (Caretta caretta) turtles in several geographic locations, using the methods of Hart et al., 2013. These instrument packages...
Stable carbon (C13) and nitrogen (N15) isotopic values of American alligators within the Florida Everglades (2013-2020) Stable carbon (C13) and nitrogen (N15) isotopic values of American alligators within the Florida Everglades (2013-2020)
This dataset contains morphometric and isotopic data for American alligators (Alligator mississippiensis) that were sampled from within four freshwater (FW) wetlands and one estuarine (EST) wetland within the Greater Everglades ecosystem. Due to their compartmentalization and varied habitat and water regimes, there were multiple sampling sites within two of the FW wetlands. The five...
Historical sea turtle relocation trawling data in the southeast U.S. (1991 - 2024) Historical sea turtle relocation trawling data in the southeast U.S. (1991 - 2024)
The U.S. Geological Survey (USGS) Wetlands Aquatic Research Center worked alongside the U.S. Army Corps of Engineers (USACE) and Bureau of Ocean Energy Management (BOEM) to amalgamate over three decades of relocation trawling records. It is USACE's mission to provide safe, reliable, efficient , and environmentally sustainable waterborne transportation systems (channels, harbors, and...
Capture histories and body size data for a population of mangrove diamond-backed terrapins (Malaclemys terrapin rhizophorarum) Everglades National Park, Florida, USA, 2001-2019 Capture histories and body size data for a population of mangrove diamond-backed terrapins (Malaclemys terrapin rhizophorarum) Everglades National Park, Florida, USA, 2001-2019
We used an 18-year dataset (2001 to 2019) incorporating year, sex, hurricane occurrence and sampling effort to estimate survival using Cormack–Jolly–Seber (CJS) models in Program Mark. Annual survivorship estimates were high from 2001-2003 for both sexes (91-96%) and variable from 2006-2014 (77-92%). Beginning in 2015 survival estimates exhibited a steeper decline (females: 65%, males 75...
Stable isotope values for Dry Tortugas nesting loggerheads sampled 2013-2018 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.
Filter Total Items: 52
Biologging to identify nesting and non-nesting emergences for four species of imperiled sea turtles Biologging to identify nesting and non-nesting emergences for four species of imperiled sea turtles
Quantifying sea turtle nesting behavior is essential for recovery planning and evaluating management actions. Traditional monitoring approaches, based on nest counts from beach surveys, can misclassify non-nesting emergences, obscure true fecundity, and underestimate clutch frequency, metrics that directly influence population models and regulatory decisions. Here, we demonstrate that...
Authors
Kristen Hart, Connor F. White, Donna J. Shaver, Margaret Lamont, Michael Cherkiss, Andrew G. Crowder, Nicholas M. Whitney
Isotopic niche plasticity of American alligators within the southern Everglades Isotopic niche plasticity of American alligators within the southern Everglades
Hydrologic alterations within the Everglades have degraded American alligator (Alligator mississippiensis) habitat, reduced prey base, and increased physiological stress. Alligator body condition declined across many management areas from 2000 through 2014, prompting us to investigate the relationship between their intraspecific isotopic niche dynamics and body condition. Alligators...
Authors
Mathew Denton, Michael Cherkiss, Frank J. Mazzotti, Laura A. Brandt, Sidney T. Godfrey, Darren Johnson, Kristen Hart
Interpreting a sudden population decline in a long-lived species (Malaclemys terrapin rhizophorarum) Interpreting a sudden population decline in a long-lived species (Malaclemys terrapin rhizophorarum)
Long-term ecological studies are critical for providing insight into population dynamics and detecting population declines, particularly for species of conservation concern. However, spatiotemporal variation and logistical challenges make the identification of sudden population declines difficult. We conducted an in-water capture-mark-recapture study of mangrove diamond-backed terrapins
Authors
Jacquelyn C. Guzy, Brian J. Smith, Mathew Denton, Michael Cherkiss, David Roche, Andrew G. Crowder, Kristen Hart
Not just corticosterone: Further characterization of the endocrine response of Kemp’s ridley sea turtles (Lepidochelys kempii) reveals elevated plasma aldosterone concentrations during field capture events Not just corticosterone: Further characterization of the endocrine response of Kemp’s ridley sea turtles (Lepidochelys kempii) reveals elevated plasma aldosterone concentrations during field capture events
To develop safe and effective management policies, it is important to understand the physiologic effects of fishing interactions and scientific research methods on endangered marine species. In the present study, validated assays for plasma corticosterone, free thyroxine (fT4), and aldosterone were used to assess the endocrine status of 61 presumed healthy, wild Kemp's ridley sea turtles
Authors
Charles J. Innis, Katherine M. Graham, Cody R. Mott, Kristen Hart, David Roche, Michael Cherkiss, Elizabeth A. Burgess
Nerodia clarkii (Saltmarsh Watersnake). Predation 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...
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 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...
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