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
Offspring, dam, sire pedigree assignments in a managed population of Brown Treesnakes on Guam
Brown Treesnake detections on transects using potential attractants of live-mouse lures or fish-spray scent, Guam
Photo-documented sequences from 01 Jun 2021 - 30 Aug 2021 showing novel interactions between intraguild predators in southern Florida, USA, bobcat and Burmese python
Exogenous and endogenous factors influence invasive reptile movement at multiple scales, 2018 - 2019
Brown Treesnake mating and reproductive success on Guam, 2004-2018
Visual Surveys and Morphometrics of Brown Treesnakes in Mariana Swiftlets caves on Guam
Salvator merianae trapping in Georgia, USA
Brown Treesnake Mortality Habitat Management Unit Guam 2019
Dataset from 2015-2016 thermal and behavior monitoring of Argentine giant tegus in Everglades, Florida
Visual Surveys Rapid Response Saipan 2016
Airsoft electric gun evaluation on Brown Treesnakes, Guam, 2016
Failed Brown Treesnake bait cartridges from an aerially application in Guam, 2018
Invasive brown treesnakes (Boiga irregularis) move short distances and have small activity areas in a high prey environment
Egg retention in wild-caught Python bivittatus in the Greater Everglades Ecosystem, Florida, USA
Chew-cards can accurately index invasive rat densities in Mariana Island forests
New state and county records of introduced amphibians and reptiles of Georgia, USA.
Face-off: Novel depredation and nest defense behaviors between an invasive and a native predator in the Greater Everglades Ecosystem, Florida, USA
Individual heterogeneity influences the effects of translocation on urban dispersal of an invasive reptile
Can we prove that an undetected species is absent? Evaluating whether brown treesnakes are established on the island of Saipan using surveillance and expert opinion
Agkistrodon conanti (Florida Cottonmouth) and Python bivittatus (Burmese Python). Diet and Predation
Demographic response of brown treesnakes to extended population suppression
Olfactory lures in predator control do not increase predation risk to birds in areas of conservation concern
Female persistence during toxicant treatment predicts survival probability of offspring in invasive brown treesnakes (Boiga irregularis)
Foraging behavior in a generalist snake (brown treesnake, Boiga irregularis) with implications for avian reintroduction and recovery
Non-USGS Publications**
**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.
Science and Products
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Filter Total Items: 29
Offspring, dam, sire pedigree assignments in a managed population of Brown Treesnakes on Guam
In this dataset offspring are assigned to a dam and sire using information from single nucleotide polymorphisms (SNPs) from previously published pedigree reassignments of Brown Treesnakes within the U.S. Geological Survey's Brown Treesnake study enclosure on Northwest Field of Andersen Air Force Base, Guam (Levine and Yackel Adams 2021 and Nafus 2021) to update the overall pedigree dataset for snaBrown Treesnake detections on transects using potential attractants of live-mouse lures or fish-spray scent, Guam
Nocturnal visual encounter surveys for Brown Treesnakes were collected and summarized into 4 plain text files (csv format): CapturesLure, SurveysLure, CapturesScent, and SurveysScent. Capture files contain unique Passive Integrated Transponder (PIT) tag identification and measurements of snakes with dates and locations of capture. Survey files contain the dates of transect sampling and treatment aPhoto-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. FirExogenous and endogenous factors influence invasive reptile movement at multiple scales, 2018 - 2019
These data reflect movement values for brown treesnakes from Guam that were translocated (moved by humans) to new locations or were resident (left in place) on Guam. The data are related to the specimen's treatment group, individual values, locations and other details affiliated with radio telemetry based acquisition and positional changes by the individual snakes across tracking events. The dataBrown Treesnake mating and reproductive success on Guam, 2004-2018
The mating and reproductive ecology of the invasive Brown Treesnake (Boiga irregularis) were generated by reconstructing a multigenerational genomic pedigree based on 654 single nucleotide polymorphisms for a geographically-closed population established in 2004 on Guam (N=426). The pedigree allowed annual estimates of individual mating and reproductive success to be inferred for snakes in the studVisual Surveys and Morphometrics of Brown Treesnakes in Mariana Swiftlets caves on Guam
Visual survey data for brown treesnakes from caves with and without swiftlets. Each record (line) represents the snake sightings that occurred during a block of time, typically 1 hour at one site by searcher(s) during one search (i.e. one date). Snakes removed from caves and adjacent areas during visual surveys were then necropsied. Each record (line) represents necropsy results for a given indiviSalvator merianae trapping in Georgia, USA
Argentine Giant Tegu lizard (Salvator merianae) trap effort and count data collected in southern Georgia, USA in 2019. Non-target species associated with the traps were also documented, as were type of bait used and condition of the traps during trap checks.Brown Treesnake Mortality Habitat Management Unit Guam 2019
The dataset contains 16 columns of data collected on invasive Brown Treesnakes (Boiga irregularis) at a study site known as the Habitat Management Unit (HMU) in northern Guam. Snakes were fitted with radio-transmitters and teams of 2-4 biologist listened for signals from transmitters every seven days to determine if snakes were alive or dead. Survival data was then modeled in Program MARK to assesDataset from 2015-2016 thermal and behavior monitoring of Argentine giant tegus in Everglades, Florida
Thermal data collected from iButton temperature loggers implanted into research animals (Argentine giant tegus) and in their surrounding environment. Tegus undergo winter dormancy (hibernation) to cope with colder temperatures, and we studied the thermal habits of wild tegus within their invaded range in southern Florida, USA. We used radiotelemetry and trail cameras to verify dates of above-grounVisual Surveys Rapid Response Saipan 2016
Nocturnal visual encounter survey data conducted by 29 searchers over 17 transects obtained during a Brown Treesnake rapid response deployment to island of Saipan in 2016. Surveys took place in the vicinity of the Saipan airport and Dandan village (ca. 15.127°N, 145.735°E) from 06 January to 13 March 2016, 6-7 nights/week but with a break in surveying from 26 January through 21 February. During BrAirsoft 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 pelletFailed 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 - Multimedia
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Filter Total Items: 79
Invasive brown treesnakes (Boiga irregularis) move short distances and have small activity areas in a high prey environment
Animal movements reflect temporal and spatial availability of resources as well as when, where, and how individuals access such resources. To test these relationships for a predatory reptile, we quantified the effects of prey abundance on the spatial ecology of invasive brown treesnakes (Boiga irregularis) on Guam. Five months after toxicant-mediated suppression of a brown treesnake population, weAuthorsScott M. Boback, Melia Gail Nafus, Amy A. Yackel Adams, Robert ReedEgg 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 opportunisticAuthorsGretchen Erika Anderson, Frank N. Ridgley, Jillian Maureen Josimovich, Robert Reed, Bryan G. Falk, Amy A. Yackel Adams, Andrea Faye CurrylowChew-cards can accurately index invasive rat densities in Mariana Island forests
Rats (Rattus spp.) are likely established on 80–90% of the world’s islands and represent one of the most damaging and expensive biological invaders. Effective rat control tools exist but require accurate population density estimates or indices to inform treatment timing and effort and to assess treatment efficacy. Capture-mark-recapture data are frequently used to produce robust density estimates,AuthorsEmma B. Hanslowe, Amy A. Yackel Adams, Melia Gail Nafus, Douglas A Page, Danielle R. Bradke, Francesca T. Erickson, Larissa L. BaileyNew state and county records of introduced amphibians and reptiles of Georgia, USA.
Recent efforts to eradicate the invasive Argentine Giant Tegu (Salvator merianae) has led to the discovery of several county records of this introduced lizard as well as several other potentially invasive amphibian and reptile species in the state of Georgia, USA. New records were determined using a database of county records maintained by the Georgia Department of Natural Resources. All specimensAuthorsMichael Brennan, Lance McBrayer, Joseph Carroll, Kenneth L. Krysko, Amy A. Yackel AdamsFace-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 ofAuthorsAndrea Faye Currylow, Matthew F. McCollister, Gretchen Erika Anderson, Jillian Maureen Josimovich, Austin Lee Fitzgerald, Christina M. Romagosa, Amy A. Yackel AdamsIndividual heterogeneity influences the effects of translocation on urban dispersal of an invasive reptile
BackgroundInvasive reptiles pose a serious threat to global biodiversity, but early detection of individuals in an incipient population is often hindered by their cryptic nature, sporadic movements, and variation among individuals. Little is known about the mechanisms that affect the movement of these species, which limits our understanding of their dispersal. Our aim was to determine whether tranAuthorsAbigail B. Fueka, Melia G. Nafus, Amy A. Yackel Adams, Larissa L. Bailey, Mevin B. HootenCan we prove that an undetected species is absent? Evaluating whether brown treesnakes are established on the island of Saipan using surveillance and expert opinion
Detection of invasive species and decisions centered around early detection and rapid response (EDRR) are notorious challenges for decision makers. Detection probability is low for cryptic species, resources are limited, and ecological harm (especially for island ecosystems) can result from failure to remove invasive species due to inadequate or delayed surveillance efforts. Due to the proximity tAuthorsAmy A. Yackel Adams, Patrick D Barnhart, Gordon H. Rodda, Eric T. Hileman, Melia Gail Nafus, Robert ReedAgkistrodon 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:N5AuthorsIan A. Bartoszek, Gretchen Erika Anderson, Ian Easterling, Jillian Maureen Josimovich, Alex Furst, Frank N. Ridgley, Austin Lee Fitzgerald, Amy A. Yackel Adams, Andrea Faye CurrylowDemographic response of brown treesnakes to extended population suppression
From a management perspective, reptiles are relatively novel invasive taxa. Few methods for reptile control have been developed and very little is known about their effectiveness for reducing reptile populations, particularly when the goal is eradication. Many reptiles, and especially snakes, are cryptic, secretive, and undergo extended periods of inactivity, traits that decrease detection probabiAuthorsMelia G. Nafus, Shane R. Siers, Brenna A. Levine, Zachary C. Quiogue, Amy A. Yackel AdamsOlfactory lures in predator control do not increase predation risk to birds in areas of conservation concern
Context: Lethal control of predators is often undertaken to protect species of conservation concern. Traps are frequently baited to increase capture efficacy, but baited traps can potentially increase predation risk by attracting predators to protected areas. This is especially important if targeted predators can escape capture due to low trap success. Snake traps using live mouse lures may be benAuthorsPage E. Klug, Amy A. Yackel Adams, Robert ReedFemale 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 managementAuthorsBrenna A Levine, Amy A. Yackel Adams, Marlis Douglas, Michael Douglas, Melia Gail NafusForaging 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 collapseAuthorsMelia G. Nafus, Peter X. Xiong, Eben H. Paxton, Amy A. Yackel Adams, Scott Michael GoetzNon-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.
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