Amy Yackel Adams is a Research Ecologist at the Fort Collins Science Center.
Amy began working for the USGS while obtaining her master and doctorate degrees in ecology starting in 1997. She is a research ecologist and principal investigator for the Invasive Reptile Program, and studies population biology with a focus on applied research of invasive organisms (snakes, lizards, small mammals). Yackel Adams’ recent research has focused on detectability of Brown Treesnakes, quantifying the impact of Brown Treesnakes on lizard populations, enhancing rapid response detection of invasive species, modeling rapid response search duration, and population estimation of small mammals in the Pacific.
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, Forestry, University of Montana, 1986
Science and Products
USGS Coordinated Burmese Python Research Strategy for South Florida (FY21 – FY27)
Biology, Impacts and Control of Invasive Reptiles in the Pacific
Fort Collins Science Center Labs and Facilities
Hierarchical Models for Estimation of Population Parameters
Biology, Impacts and Control of Invasive Reptiles in the Everglades
USGS Everglades Research Office - Florida
USGS Brown Treesnake Laboratory - Guam
Ecology and Control of Invasive Reptiles in Florida
Brown Treesnake Rapid Response Team
Control and Landscape-Scale Suppression of the Invasive Brown Treesnake
Giant Constrictor Snakes in Florida: A Sizeable Research Challenge
Invasive Species in the Everglades – An Opportunity to Engage Youth in Science
Size distribution and reproductive data of the invasive Burmese python (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida, USA, 1995-2021
Data for analysis of open removal models with temporary emigration and population dynamics to inform invasive animal management
Spatial mark-recapture and chew card rat data on Guam and Rota, 2018-2019
Brown treesnake capture and morphometric data using live mouse- and bird-lure traps on Guam, 2013
Camera trap data of Brown Treesnakes at mouse-lure traps on Guam, 2015
Brown Treesnake morphological and behavioral differences following ingestion of large meals, 2015
Surveillance and reports of Brown Treesnakes on Saipan, 1980-2020
Brown Treesnake trap captures, Guam National Wildlife Refuge, 2014
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
Burmese pythons in Florida: A synthesis of biology, impacts, and management tools
Size distribution and reproductive phenology of the invasive Burmese python (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida, USA
Open removal models with temporary emigration and population dynamics to inform invasive animal management
Egg retention in wild-caught Python bivittatus in the Greater Everglades Ecosystem, Florida, 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
- Science
USGS Coordinated Burmese Python Research Strategy for South Florida (FY21 – FY27)
Wetland and Aquatic Research Center and Fort Collins Science Center are coordinating a long-term, landscape-scale Burmese python research strategy for South Florida.Biology, Impacts and Control of Invasive Reptiles in the Pacific
Research on Guam has led to development and validation of numerous effective control tools, including the advancement of reptile control to support native species recovery.Fort Collins Science Center Labs and Facilities
The Fort Collins Science Center has scientists working in several diverse locations as well as three in house highly specialized laboratories, studying subjects from molecular ecology to brown treesnakes, dendroecology to streamflows, and macroinvertebrate species to Burmese pythons. Our extraordinary scientists work in each of these locations advancing studies in their particluar areas of study...Hierarchical Models for Estimation of Population Parameters
The Challenge: Much of wildlife research consists of the description of variation in data. Some of the variation results from spatial and temporal change in populations, while some results from biologically irrelevant sampling variation induced by the process of data collection. Distinguishing relevant from irrelevant variation is the first task of statistical analysis, but the job does not end...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.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...USGS Brown Treesnake Laboratory - Guam
USGS scientists and staff associated with the Brown Treesnake Project are co-located at the Guam National Wildlife Refuge at the northern end of Guam in the western Pacific Ocean. Project staff work on developing and testing control tools for invasive brown treesnakes, as well as understanding their impacts on Guam's ecosystems. Project staff also lead the multi-agency Brown Treesnake Rapid...Ecology and Control of Invasive Reptiles in Florida
This project involves ongoing development of tools for the detection and capture of invasive reptiles in Florida, with an emphasis on Burmese pythons (Python bivittatus) and Black and white tegu lizards (Salvator merianae). The goals are to reduce the risk of reptile invasions in high-value resources such as Everglades National Park and the Florida Keys, to access early detection methods of new...Brown Treesnake Rapid Response Team
Brown Treesnakes continue to cause major problems for the ecology, economy, and quality of life on Guam. Our scientists conduct research on this snake species, including control tool development and testing, ecological impacts, and early detection methods. We hold Brown Treesnake Rapid Response Team training courses on Guam throughout the year to develop the skills needed to effectively respond to...Control and Landscape-Scale Suppression of the Invasive Brown Treesnake
The Brown Treesnake is a highly destructive reptile species that has extirpated many native species of birds, bats, and lizards from the U.S. Territory of Guam. For more than two decades branch scientists with the Invasive Reptile Project have developed, validated, and tested the feasibility of Brown Treesnake control and suppression at various spatial scales.Giant Constrictor Snakes in Florida: A Sizeable Research Challenge
Since the mid-1990s, several species of non-native, giant constrictor snakes, such as Burmese pythons and boa constrictors, have surfaced in localities throughout southern Florida. Several are known or suspected to be breeding and appear to be spreading northward. Increasingly, media and other reports of sightings or encounters with these animals have emphasized the dangers they could impose on...Invasive Species in the Everglades – An Opportunity to Engage Youth in Science
Invasive reptiles like the Burmese python (Python bivittatus) and Black-and-White Tegu Lizard (Tupinambis merianae) are exerting tremendous harm on Everglades ecosystems, but these problematic species present an excellent opportunity to engage the next generation in science. Since entering into an agreement with Everglades National Park in late 2013, the Invasive Species Science Branch of the U.S... - Data
Filter Total Items: 23
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 PreData for analysis of open removal models with temporary emigration and population dynamics to inform invasive animal management
This data release includes the data and computer code that we produced to fit two open-robust design removal models developed to simultaneously model population dynamics, temporary emigration, and imperfect detection: a random walk linear trend model (estimable without ancillary information), and a 2-age class integrated population model (IPM) that used prior information for age-structured vital rSpatial mark-recapture and chew card rat data on Guam and Rota, 2018-2019
We provide four datasets: Mark recapture and trapping effort, Grid layout, Chew cards, and Trail camera validation. Mark recapture and trapping effort has one row for every live-trap night, including the unique grid identification code, date of trap check, cumulative rain amount from the 24-hr period before the trap check, unique trap identification, trap status, unique individual rat identificatiBrown treesnake capture and morphometric data using live mouse- and bird-lure traps on Guam, 2013
We deployed 30 trap stations consisting of three combinations: isolated bird-lure traps, isolated mouse-lure traps, or paired stations to evaluate snake capture as a function of lure. At the paired stations, we included two traps: one bird-lure trap and one mouse-lure trap. All stations were at least 60 meters (m) apart and each of the station treatments was replicated 10 times. Traps at paired stCamera trap data of Brown Treesnakes at mouse-lure traps on Guam, 2015
Manually photo-processed remote camera trap data of Brown Treesnakes on Guam at snake traps with live mouse lures. Records of snakes entering the field of view (FOV) and exiting the FOV by day, time, and trap location. Photos were further processed to retain only detections of snakes up to 1.83 meters from the camera, i.e., only records of snakes that were on or in front of the mouse-lure trap areBrown Treesnake morphological and behavioral differences following ingestion of large meals, 2015
Data set resulting from monitoring the behavior of snakes (n = 62) that had been feed a standardized large meal with transmitter, proportional to their body mass, to make direct comparisons to a control group of snakes that had not been fed a meal (only the transmitter). Transmitters were equipped with a two-position switch that changes pulse rate when the body position of the animal changes moreSurveillance and reports of Brown Treesnakes on Saipan, 1980-2020
Available active surveillance efforts for Brown Treesnakes on the island of Saipan via nocturnal visual encounter surveys and trapping from 1999-2018 were collected and summarized into 3 csv files (TRAP1999, BTSRRTSaipanTRAP, and BTSRRTSaipanVISUAL). Location and date of non-confirmed reports of snakes 1982-2013 via passive surveillance were compiled into a fourth file (Saipan BTSSightings1980_202Brown Treesnake trap captures, Guam National Wildlife Refuge, 2014
Over a 22-week period both with and without active Brown Treesnake (BTS) snake removal, we evaluated snake-trap contact rates at mouse- and bird-lure traps within the Guam National Wildlife Refuge in 2014. Bird-lure traps served as a proxy for reintroduced nesting birds. Data consists of 3 files generated from camera surveillance and trapping using mouse and bird lures in conventional snake trapsBrown 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 stud - Multimedia
- Publications
Filter Total Items: 67
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 fSize 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 anOpen removal models with temporary emigration and population dynamics to inform invasive animal management
Removal sampling data are the primary source of monitoring information for many populations (e.g., invasive species, fisheries). Population dynamics, temporary emigration, and imperfect detection are common sources of variation in monitoring data and are key parameters for informing management. We developed two open robust-design removal models for simultaneously modeling population dynamics, tempEgg 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 opportunisticFace-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 ofIndividual 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 tranCan 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 tAgkistrodon 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:N5Demographic 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 probabiOlfactory 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 benFemale 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 managementForaging 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 collapseNon-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.
- News