Amy Yackel Adams, PhD
Amy Yackel Adams is a Research Ecologist focusing on improving management decisions of invasive reptiles worldwide.
Amy leads a diverse research program with other USGS scientists and various collaborators (NPS, USDA-NWRC, USFWS, DoD, universities, and state agencies) pertaining to early detection and rapid response, biology, ecology, genetics, control tool evaluation, eradication, and quantitative model development to improve adaptive management of invasive reptile species. Yackel Adams’ research areas in the Greater Everglades Ecosystem and Pacific Islands include: 1) Population and vital rate estimation of invasive Burmese Pythons, Veiled Chameleons, and Brown Treesnakes; 2) Estimating the impact of Brown Treesnakes on prey populations; 3) Enhancing early detection of invasive reptiles using new tools; and 4) Development and evaluation of removal and abundance models to inform and optimize eradication efforts.
Education and Certifications
PhD, Ecology, Graduate Degree Program in Ecology, Colorado State University, 2005
MS, Ecology, Graduate Degree Program in Ecology, Colorado State University, 1999
BS, Resource Conservation and Environmental Studies, University of Montana, 1986
Science and Products
Filter Total Items: 82
Female persistence during toxicant treatment predicts survival probability of offspring in invasive brown treesnakes (Boiga irregularis)
Assessing the long-term efficacy of control methods is a critical component of invasive species management. For example, if traits related to control have significant heritability or are influenced by maternal effects, control methods may lose efficacy over time. The potential for these effects can be evaluated via parent/offspring survival analysis, which concomitantly recasts adaptive management
Authors
Brenna A Levine, Amy A. Yackel Adams, Marlis Douglas, Michael Douglas, Melia Gail Nafus
Foraging behavior in a generalist snake (brown treesnake, Boiga irregularis) with implications for avian reintroduction and recovery
Broad foraging classifications, such as generalist or specialist forager, are generally beneficial for population management in defining expectations of typical behavior. However, better understanding as to how individual variance in behavior interfaces with management actions, such as control of an invasive predator (such as brown treesnakes; Boiga irregularis) responsible for ecological collapse
Authors
Melia G. Nafus, Peter X. Xiong, Eben H. Paxton, Amy A. Yackel Adams, Scott Michael Goetz
Thermal stability of an adaptable, invasive ectotherm: Argentine giant tegus in the Greater Everglades ecosystem, USA
Invasive species globally threaten biodiversity and economies, but the ecophysiological mechanisms underlying their success are often understudied. For those alien species that also exhibit high phenotypic plasticity, such as habitat generalists, adaptations in response to environmental pressures can take place relatively quickly. The Argentine giant tegu (Salvator merianae; tegu) is a large omniv
Authors
Andrea Faye Currylow, Michelle Collier, Emma B. Hanslowe, Bryan G. Falk, Brian S. Cade, Sarah E. Moy, Alejandro Grajal-Puche, Frank N. Ridgley, Robert Reed, Amy A. Yackel Adams
Brown treesnake mortality after aerial application of toxic baits
Quantitative evaluation of control tools for managing invasive species is necessary to assess overall effectiveness and individual variation in treatment susceptibility. Invasive brown treesnakes (Boiga irregularis) on Guam have caused severe ecological and economic effects, pose a risk of accidental introduction to other islands, and are the greatest impediment to the reestablishment of extirpate
Authors
Scott Michael Goetz, Eric T. Hileman, Melia G. Nafus, Amy A. Yackel Adams, Amanda R Bryant, Robert Reed, Shane R. Siers
Evaluation of camera trap-based abundance estimators for unmarked populations
Estimates of species abundance are critical to understand population processes and to assess and select management actions. However, capturing and marking individuals for abundance estimation, while providing robust information, can be economically and logistically prohibitive, particularly for species with cryptic behavior. Camera traps can be used to collect data at temporal and spatial scales n
Authors
S M Amburgey, Amy A. Yackel Adams, B. Gardner, N.J. Hostetter, S.R. Siers, B.T. McClintock, Sarah J. Converse
Trait heritability and its implications for the management of an invasive vertebrate
Control methods that target specific traits of an invasive species can produce results contrary to the aims of management. If targeted phenotypes exhibit heritability, then it follows that the invasive species could evolve greater resistance to the applied control measures over time. Additional complications emerge if those traits targeted by control are also inversely related to reproductive succ
Authors
Brenna A Levine, Marlis R Douglas, Amy A. Yackel Adams, Bjorn Lardner, Robert Reed, Julie A. Savidge, Michael E Douglas
Surface material and snout-vent length predict vertical scaling ability in brown treesnakes:an evaluation of multispecies barriers for invasive species control on Guam
The combination of snake-proof barriers and an aerial toxicant delivery system for snake suppression may allow large-scale control of invasive brown treesnakes (Boiga irregularis) on Guam. However, suppression or local eradication of several other species (e.g., introduced ungulates, cats, rodents) may be required for successful restoration and recovery of forest habitat and reintroduction of nati
Authors
Eric T. Hileman, DR Bradke, Melia G. Nafus, Amy A. Yackel Adams, Robert Reed
Using enclosed Y-mazes to assess chemosensory behavior in reptiles
Reptiles utilize a variety of environmental cues to inform and drive animal behavior such as chemical scent trails produced by food or conspecifics. Decrypting the scent-trailing behavior of vertebrates, particularly invasive species, enables the discovery of cues that induce exploratory behavior and can aid in the development of valuable basic and applied biological tools. However, pinpointing be
Authors
M. Rockwell Parker, Andrea Faye Currylow, Eric A. Tillman, Charlotte J. Robinson, Jillian Maureen Josimovich, Isabella M.G. Bukovich, Lauren A. Nazarian, Melia G. Nafus, Bryan M. Kluever, Amy A. Yackel Adams
Locally abundant, endangered Mariana swiftlets impact the abundance, behavior, and body condition of an invasive predator
Invasive predators are known to have negative consumptive and non-consumptive effects on native species, but few examples show how the abundance of native prey may influence an established invasive predator. We compared invasive brown treesnakes (Boiga irregularis; BTS) found in caves occupied by endangered Mariana swiftlets (Aerodramus bartschi) to snakes found in nearby forests and caves without
Authors
Page E. Klug, Amy A. Yackel Adams, Shane R. Siers, Kevin M Brindock, Stephen M. Mosher, MJ Mazurek, William C. Pitt, Robert Reed
Evidence for an established population of tegu lizards Salvator merianae in southeastern Georgia, USA
Documenting emergence of invasive species in new areas is vital to understanding spatiotemporal patterns of invasions, propagule pressure, and the risk of establishment. Salvator merianae (Argentine Giant Tegu) has established multiple unconnected populations in southern and Central Florida, and additional sightings have been reported elsewhere in the state. In 2018, land managers in Georgia recei
Authors
Daniel Haro, Lance McBrayer, John B Jenson, James Gillis, Lea R. Bonewell, Melia Gail Nafus, Stephen E. Greiman, Robert Reed, Amy A. Yackel Adams
Validating deployment of aerially delivered toxic bait cartridges for control of invasive brown treesnakes
Aerial application of management tools can provide a cost‐effective means to conserve or control wildlife populations at the landscape scale. Large spatial scales, however, present difficulties when assessing in situ reliability and integrity of the devices themselves. We demonstrate application of a distance‐sampling density estimation approach to assess the performance of a newly developed toxic
Authors
Scott Michael Goetz, Amy A. Yackel Adams, Shane S Siers
Behavior, size, and body condition predict susceptibility to management and reflect post-treatment frequency shifts in an invasive snake
Foraging behavior can have population-level effects that are of interest for wildlife management. For invasive species, foraging behavior has been tied to establishment ability and rate of spread and is generally of import in understanding invasion biology. A major method for controlling invasive vertebrates is using food-based baits as attractants. Tool efficacy is therefore partially driven by i
Authors
Melia G. Nafus, Amy A. Yackel Adams, S. M. Boback, SR Siers, Robert Reed
Non-USGS Publications**
Graham, L., A.A. Yackel Adams, and E.A. Odell. 1999. Devaluation of non-experiments in the current ecological paradigm. Wildlife Society Bulletin. 26(4): 1002-1006.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Filter Total Items: 13
Filter Total Items: 31
Airsoft electric gun evaluation on Brown Treesnakes, Guam, 2016
The data set consists of 2 spreadsheets from Airsoft Electric Gun (AEG) trials on brown treesnakes. AEG snake wound data contains AEG results from guns equipped with 0.39 gram ammunition (plastic pellets ) that were fired at dead and live snakes from distances of 4, 8, and 12 m to measure tissue-penetration depth, and noted if (a) the pellet was lodged inside the peritoneal cavity, (b) the pellet
Failed Brown Treesnake bait cartridges from an aerially application in Guam, 2018
The dataset contains 6 columns of data collected during line transect surveys (Line) that evaluated bait cartridge efficacy for Brown Treesnake control on Guam. Two-person teams recorded all bait cartridges observed while walking the center line of transects in the Habitat Management Unit (HMU). Perpendicular distance (DIST (m)) to cartridges from center line was measured to the nearest 0.005 mete
Brown Treesnake counts during visual encounter surveys at three walking paces, Guam 2016
We evaluated three walking paces to estimate (1) how snake detection rate per unit distance changes with increasing pace, and (2) how total number of snakes found by the end of a night of surveying varies with pace when the amount of surveying time per night is held constant. For a ?fast? pace we searched the 220 meter-long transect in 10 minutes, corresponding to a walking pace of 1.32 km/h, wher
Brown Treesnake visual survey and radiotelemetry data, Guam 2015
The dataset consists of two spreadsheets that contain brown treesnake data (location, perch taxa, perch height, time of detection, whether visible or not, and size of snake) collected during both visual surveys and radio telemetry within a 55-ha enclosure on Guam.
Removal count data of Veiled Chameleons on Maui, 2002-2012
The data set consists of 3 spreadsheets: counts, efforts, and location that detail the 10-year removal effort of invasive Veiled Chameleons (Chamaeleo calyptratus) on the island of Maui. Recorded are the number of lizards removed from each site, the level of search effort at each site, and the centroid location of each sampled site.
Habitat characterization around standard brown treesnake traps on Guam, 2004 - 2017
Data were collected in association with locations of standard brown treesnake traps on Guam at location prior to suppression or control efforts and after control had occurred. In all cases study sites were closed or semi-closed populations of brown treesnakes. Habitat data focused on type and structure of the habitat within 10-m of the trap.
Dataset: Passive restoration following ungulate removal in a highly disturbed tropical wet forest devoid of native seed dispersers
On an island largely devoid of native vertebrate seed dispersers, we monitored forest succession for seven years following ungulate exclusion from a 5-hectare area and adjacent plots with ungulates still present. The study site was in northern Guam on Andersen Air Force Base (1337N, 14451E) and situated on a coralline limestone plateau. We established 22 plots and six 0.25-m2 subplots to measure t
Science and Products
Filter Total Items: 82
Female persistence during toxicant treatment predicts survival probability of offspring in invasive brown treesnakes (Boiga irregularis)
Assessing the long-term efficacy of control methods is a critical component of invasive species management. For example, if traits related to control have significant heritability or are influenced by maternal effects, control methods may lose efficacy over time. The potential for these effects can be evaluated via parent/offspring survival analysis, which concomitantly recasts adaptive management
Authors
Brenna A Levine, Amy A. Yackel Adams, Marlis Douglas, Michael Douglas, Melia Gail Nafus
Foraging behavior in a generalist snake (brown treesnake, Boiga irregularis) with implications for avian reintroduction and recovery
Broad foraging classifications, such as generalist or specialist forager, are generally beneficial for population management in defining expectations of typical behavior. However, better understanding as to how individual variance in behavior interfaces with management actions, such as control of an invasive predator (such as brown treesnakes; Boiga irregularis) responsible for ecological collapse
Authors
Melia G. Nafus, Peter X. Xiong, Eben H. Paxton, Amy A. Yackel Adams, Scott Michael Goetz
Thermal stability of an adaptable, invasive ectotherm: Argentine giant tegus in the Greater Everglades ecosystem, USA
Invasive species globally threaten biodiversity and economies, but the ecophysiological mechanisms underlying their success are often understudied. For those alien species that also exhibit high phenotypic plasticity, such as habitat generalists, adaptations in response to environmental pressures can take place relatively quickly. The Argentine giant tegu (Salvator merianae; tegu) is a large omniv
Authors
Andrea Faye Currylow, Michelle Collier, Emma B. Hanslowe, Bryan G. Falk, Brian S. Cade, Sarah E. Moy, Alejandro Grajal-Puche, Frank N. Ridgley, Robert Reed, Amy A. Yackel Adams
Brown treesnake mortality after aerial application of toxic baits
Quantitative evaluation of control tools for managing invasive species is necessary to assess overall effectiveness and individual variation in treatment susceptibility. Invasive brown treesnakes (Boiga irregularis) on Guam have caused severe ecological and economic effects, pose a risk of accidental introduction to other islands, and are the greatest impediment to the reestablishment of extirpate
Authors
Scott Michael Goetz, Eric T. Hileman, Melia G. Nafus, Amy A. Yackel Adams, Amanda R Bryant, Robert Reed, Shane R. Siers
Evaluation of camera trap-based abundance estimators for unmarked populations
Estimates of species abundance are critical to understand population processes and to assess and select management actions. However, capturing and marking individuals for abundance estimation, while providing robust information, can be economically and logistically prohibitive, particularly for species with cryptic behavior. Camera traps can be used to collect data at temporal and spatial scales n
Authors
S M Amburgey, Amy A. Yackel Adams, B. Gardner, N.J. Hostetter, S.R. Siers, B.T. McClintock, Sarah J. Converse
Trait heritability and its implications for the management of an invasive vertebrate
Control methods that target specific traits of an invasive species can produce results contrary to the aims of management. If targeted phenotypes exhibit heritability, then it follows that the invasive species could evolve greater resistance to the applied control measures over time. Additional complications emerge if those traits targeted by control are also inversely related to reproductive succ
Authors
Brenna A Levine, Marlis R Douglas, Amy A. Yackel Adams, Bjorn Lardner, Robert Reed, Julie A. Savidge, Michael E Douglas
Surface material and snout-vent length predict vertical scaling ability in brown treesnakes:an evaluation of multispecies barriers for invasive species control on Guam
The combination of snake-proof barriers and an aerial toxicant delivery system for snake suppression may allow large-scale control of invasive brown treesnakes (Boiga irregularis) on Guam. However, suppression or local eradication of several other species (e.g., introduced ungulates, cats, rodents) may be required for successful restoration and recovery of forest habitat and reintroduction of nati
Authors
Eric T. Hileman, DR Bradke, Melia G. Nafus, Amy A. Yackel Adams, Robert Reed
Using enclosed Y-mazes to assess chemosensory behavior in reptiles
Reptiles utilize a variety of environmental cues to inform and drive animal behavior such as chemical scent trails produced by food or conspecifics. Decrypting the scent-trailing behavior of vertebrates, particularly invasive species, enables the discovery of cues that induce exploratory behavior and can aid in the development of valuable basic and applied biological tools. However, pinpointing be
Authors
M. Rockwell Parker, Andrea Faye Currylow, Eric A. Tillman, Charlotte J. Robinson, Jillian Maureen Josimovich, Isabella M.G. Bukovich, Lauren A. Nazarian, Melia G. Nafus, Bryan M. Kluever, Amy A. Yackel Adams
Locally abundant, endangered Mariana swiftlets impact the abundance, behavior, and body condition of an invasive predator
Invasive predators are known to have negative consumptive and non-consumptive effects on native species, but few examples show how the abundance of native prey may influence an established invasive predator. We compared invasive brown treesnakes (Boiga irregularis; BTS) found in caves occupied by endangered Mariana swiftlets (Aerodramus bartschi) to snakes found in nearby forests and caves without
Authors
Page E. Klug, Amy A. Yackel Adams, Shane R. Siers, Kevin M Brindock, Stephen M. Mosher, MJ Mazurek, William C. Pitt, Robert Reed
Evidence for an established population of tegu lizards Salvator merianae in southeastern Georgia, USA
Documenting emergence of invasive species in new areas is vital to understanding spatiotemporal patterns of invasions, propagule pressure, and the risk of establishment. Salvator merianae (Argentine Giant Tegu) has established multiple unconnected populations in southern and Central Florida, and additional sightings have been reported elsewhere in the state. In 2018, land managers in Georgia recei
Authors
Daniel Haro, Lance McBrayer, John B Jenson, James Gillis, Lea R. Bonewell, Melia Gail Nafus, Stephen E. Greiman, Robert Reed, Amy A. Yackel Adams
Validating deployment of aerially delivered toxic bait cartridges for control of invasive brown treesnakes
Aerial application of management tools can provide a cost‐effective means to conserve or control wildlife populations at the landscape scale. Large spatial scales, however, present difficulties when assessing in situ reliability and integrity of the devices themselves. We demonstrate application of a distance‐sampling density estimation approach to assess the performance of a newly developed toxic
Authors
Scott Michael Goetz, Amy A. Yackel Adams, Shane S Siers
Behavior, size, and body condition predict susceptibility to management and reflect post-treatment frequency shifts in an invasive snake
Foraging behavior can have population-level effects that are of interest for wildlife management. For invasive species, foraging behavior has been tied to establishment ability and rate of spread and is generally of import in understanding invasion biology. A major method for controlling invasive vertebrates is using food-based baits as attractants. Tool efficacy is therefore partially driven by i
Authors
Melia G. Nafus, Amy A. Yackel Adams, S. M. Boback, SR Siers, Robert Reed
Non-USGS Publications**
Graham, L., A.A. Yackel Adams, and E.A. Odell. 1999. Devaluation of non-experiments in the current ecological paradigm. Wildlife Society Bulletin. 26(4): 1002-1006.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Filter Total Items: 13
Filter Total Items: 31
Airsoft electric gun evaluation on Brown Treesnakes, Guam, 2016
The data set consists of 2 spreadsheets from Airsoft Electric Gun (AEG) trials on brown treesnakes. AEG snake wound data contains AEG results from guns equipped with 0.39 gram ammunition (plastic pellets ) that were fired at dead and live snakes from distances of 4, 8, and 12 m to measure tissue-penetration depth, and noted if (a) the pellet was lodged inside the peritoneal cavity, (b) the pellet
Failed Brown Treesnake bait cartridges from an aerially application in Guam, 2018
The dataset contains 6 columns of data collected during line transect surveys (Line) that evaluated bait cartridge efficacy for Brown Treesnake control on Guam. Two-person teams recorded all bait cartridges observed while walking the center line of transects in the Habitat Management Unit (HMU). Perpendicular distance (DIST (m)) to cartridges from center line was measured to the nearest 0.005 mete
Brown Treesnake counts during visual encounter surveys at three walking paces, Guam 2016
We evaluated three walking paces to estimate (1) how snake detection rate per unit distance changes with increasing pace, and (2) how total number of snakes found by the end of a night of surveying varies with pace when the amount of surveying time per night is held constant. For a ?fast? pace we searched the 220 meter-long transect in 10 minutes, corresponding to a walking pace of 1.32 km/h, wher
Brown Treesnake visual survey and radiotelemetry data, Guam 2015
The dataset consists of two spreadsheets that contain brown treesnake data (location, perch taxa, perch height, time of detection, whether visible or not, and size of snake) collected during both visual surveys and radio telemetry within a 55-ha enclosure on Guam.
Removal count data of Veiled Chameleons on Maui, 2002-2012
The data set consists of 3 spreadsheets: counts, efforts, and location that detail the 10-year removal effort of invasive Veiled Chameleons (Chamaeleo calyptratus) on the island of Maui. Recorded are the number of lizards removed from each site, the level of search effort at each site, and the centroid location of each sampled site.
Habitat characterization around standard brown treesnake traps on Guam, 2004 - 2017
Data were collected in association with locations of standard brown treesnake traps on Guam at location prior to suppression or control efforts and after control had occurred. In all cases study sites were closed or semi-closed populations of brown treesnakes. Habitat data focused on type and structure of the habitat within 10-m of the trap.
Dataset: Passive restoration following ungulate removal in a highly disturbed tropical wet forest devoid of native seed dispersers
On an island largely devoid of native vertebrate seed dispersers, we monitored forest succession for seven years following ungulate exclusion from a 5-hectare area and adjacent plots with ungulates still present. The study site was in northern Guam on Andersen Air Force Base (1337N, 14451E) and situated on a coralline limestone plateau. We established 22 plots and six 0.25-m2 subplots to measure t