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Melia Nafus, Ph.D.

Melia Nafus is a Research Ecologist at the Pacific Island Ecosystems Research Center. 

Melia leads the USGS Brown Treesnake Project based in the Marianas where her research is focused on improving detection and capture of cryptic reptiles at low densities, potential ecological effects of snake control, and development and implementation of control measures to enact population suppression on Guam and prevent their spread to other Pacific Islands. She also develops and collaborates on research designed to inform ecology and species recovery needs in the Pacific and elsewhere, as well as invasive reptile ecology. Broadly speaking, Melia is interested in factors that affect persistence of herpetofaunal populations including behavior, habitat selection, population dynamics, and spatial use.

Professional Experience

  • 2016 to Present, Research Ecologist, U.S. Geological Survey

  • 2014 to 2016, Researcher, San Diego Zoo Global Institute for Conservation Research, Escondido California

Education and Certifications

  • Ph.D. Ecology, Graduate Group in Ecology, University of California Davis, 2014

  • B.S. Biology, Department of Biological Sciences, University of Idaho, 2007

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Photo of a small snake in Guam

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.
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Fort Collins Science Center
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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.
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USGS

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...
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center
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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...
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A brown treesnake on frangipangi blossoms, by Bjorn Lardner, USGS.

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...
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Fort Collins Science Center, Pacific Island Ecosystems Research Center
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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...
Learn More
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A brown treesnake in a tree in Guam. Photo by Bob Reed, USGS, 2009.

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.
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center
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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.
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Brown treesnake movement following snake suppression in the Habitat Management Unit on Northern Guam from 2015

Animals move to locate important resources such as food, water, and mates. Therefore, movement patterns can 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).
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Fort Collins Science Center

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
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Fort Collins Science Center

Exogenous 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 data
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Fort Collins Science Center

Activity and habitat selection by female desert tortoises in Mojave National Preserve, California USA 2011 - 2013

These data refer to habitat and activity data collected for female desert tortoises being monitored as part of a study on juvenile rearing and translocation for population augmentation purposes. The females were affixed with radio transmitters and radio tracked at least monthly to maintain knowledge of whereabouts. During those tracking events activity data were collected (surface or in burrows) a
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Fort Collins Science Center

Monitoring mortality of brown treesnakes fed an oral toxicant (acetaminophen) in an external bait placement dosing technique in the laboratory, 2017

Accidentally introduced to Guam, the brown treesnake (BTS) has extirpated nearly all native forest birds and imposed cost millions of dollars in economic damages annually. Acetaminophen is a safe and effective oral toxicant for invasive BTS, and an automated aerial delivery system (ADS) has been developed for landscape-scale distribution and snake suppression. An 80 milligram dose has proven 100%
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Fort Collins Science Center

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 asses
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Fort Collins Science Center

Data associated with toxicant applications for brown treesnake control

This file describes three datasets used to evaluate individual traits in brown treesnakes and how they affect susceptibility to toxicant applications. This file references three data sets that include 'Guam GROUND', SURVTOX', and 'HMU NWFN TRT.' Guam GROUND reference to snakes encountered during visual surveys on Guam and whether they were located on the ground or arboreal. SURVTOX refers to a kno
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Fort Collins Science Center

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.
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Fort Collins Science Center

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.
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Fort Collins Science Center

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
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Fort Collins Science Center
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Filter Total Items: 27

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
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Ecosystems Mission Area, Fort Collins Science Center, Pacific Island Ecosystems Research Center, Wetland and Aquatic Research Center

Boiga irregularis (brown treesnake)

No abstract available.
Authors
Patrick D Barnhart, Zachary C. Quiogue, Elisabeth Frasch, Diane Vice, Charlene Beverly Hopkins, Amy A. Yackel Adams, Robert Reed, Melia Gail Nafus
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Ecosystems Mission Area, Fort Collins Science Center

Chew-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,
Authors
Emma B. Hanslowe, Amy A. Yackel Adams, Melia Gail Nafus, Douglas A Page, Danielle R. Bradke, Francesca T. Erickson, Larissa L. Bailey
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Ecosystems Mission Area, Fort Collins Science Center

Individual 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 tran
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Abigail B. Fueka, Melia G. Nafus, Amy A. Yackel Adams, Larissa L. Bailey, Mevin B. Hooten
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

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

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 t
Authors
Amy A. Yackel Adams, Patrick D Barnhart, Gordon H. Rodda, Eric T. Hileman, Melia Gail Nafus, Robert Reed
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center, Pacific Island Ecosystems Research Center

Demographic 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 probabi
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Melia G. Nafus, Shane R. Siers, Brenna A. Levine, Zachary C. Quiogue, Amy A. Yackel Adams
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

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
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Brenna A Levine, Amy A. Yackel Adams, Marlis Douglas, Michael Douglas, Melia Gail Nafus
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

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
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center, Pacific Island Ecosystems Research Center

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
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

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
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

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
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

Evaluating lethal toxicant doses for the largest individuals of an invasive vertebrate predator with indeterminate growth

The brown treesnake (Boiga irregularis) was accidentally introduced to Guam and caused severe ecological and economic damages. Acetaminophen is an effective, low-risk oral toxicant for invasive brown treesnakes, and an automated aerial delivery system (ADS) has been developed for landscape-scale toxic bait distribution. A fixed dose of 80 mg of acetaminophen within a tablet inserted into a dead ne
Authors
Shane R. Siers, Scott Michael Goetz, Rachel M. Volsteadt, Melia G. Nafus
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Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Fort Collins Science Center

Non-USGS Publications**

Nafus MG, Todd BD, Buhlmann KA, and Tuberville TD (2015) Consequences of maternal effects on offspring size, growth and survival in the desert tortoise. Journal of Zoology, London, 297:108-114. http://dx.doi.org/10.1111/jzo.12250
Nafus MG (2015) Indeterminate growth in desert tortoises. Copeia, 103: 520-524. http://dx.doi.org/10.1643/CH-14-192
Peaden JM, Tuberville TD, Buhlmann KA, Nafus MG, and Todd BD (2015) Delimiting road-effect zones for threatened species: implications for mitigation fencing. Wildlife Research, 42: 650-659. http://dx.doi.org/10.1071/WR15082
Nafus MG, Tuberville TD, Buhlmann KA, and Todd BD (2013) Occurrence and demographic structure of Agassiz’s desert tortoise (Gopherus agassizii) along roads of varying size and traffic volume. Biological Conservation, 162: 100-106. http://dx.doi.org/10.1016/j.biocon.2013.04.009
Bunting JE, Giles DA, Nafus MG, Nemeth Z, Poletto JB, Roe SM, Thomas RE, VanderWaal K, Caro T. (2011) A primer of conservation behavior. Animal Behaviour, 81: 353-355. http://dx.doi.org/10.1016/j.anbehav.2010.10.011

**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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