Melia Nafus is a Research Ecologist at the Fort Collins Science 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 in the Everglades. 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
Science and Products
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
Demographic response of brown treesnakes to extended population suppression
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
Brown treesnake mortality after aerial application of toxic baits
Surface material and snout-vent length predict vertical scaling ability in brown treesnakes:an evaluation of multispecies barriers for invasive species control on Guam
Using enclosed Y-mazes to assess chemosensory behavior in reptiles
Evaluating lethal toxicant doses for the largest individuals of an invasive vertebrate predator with indeterminate growth
Evidence for an established population of tegu lizards Salvator merianae in southeastern Georgia, USA
Hemidactylus cf. platyurus (Asian flat-tailed house gecko)
Hemidactylus tenkatei (Spotted house gecko)
Pre-USGS Publications
Biology, Impacts and Control of Invasive Reptiles in the Pacific
Fort Collins Science Center Labs and Facilities
Biology, Impacts and Control of Invasive Reptiles in the Everglades
USGS Brown Treesnake Laboratory and Rapid Response Facility - 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
Exogenous and endogenous factors influence invasive reptile movement at multiple scales, 2018 - 2019
Activity and habitat selection by female desert tortoises in Mojave National Preserve, California USA 2011 - 2013
Monitoring mortality of brown treesnakes fed an oral toxicant (acetaminophen) in an external bait placement dosing technique in the laboratory, 2017
Brown Treesnake Mortality Habitat Management Unit Guam 2019
Data associated with toxicant applications for brown treesnake control
Brown Treesnake visual survey and radiotelemetry data, Guam 2015
Habitat characterization around standard brown treesnake traps on Guam, 2004 - 2017
Dataset: Passive restoration following ungulate removal in a highly disturbed tropical wet forest devoid of native seed dispersers
Science and Products
- Publications
Filter Total Items: 24
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 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 tDemographic 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 probabiFemale 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 collapseBrown 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 extirpateSurface 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 natiUsing 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 beEvaluating 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 neEvidence 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 receiHemidactylus cf. platyurus (Asian flat-tailed house gecko)
No abstract available.Hemidactylus tenkatei (Spotted house gecko)
No abstract available.Pre-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.12250Nafus 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/WR15082Nafus 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.2013.04.009Bunting 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 - Science
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...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 Brown Treesnake Laboratory and Rapid Response Facility - 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... - Data
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 dataActivity 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) aMonitoring 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%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 assesData 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 knoBrown 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.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