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  • Boiga irregularis on the invasive plant Chromolaena odorata tree (Photo: Gordon Rodda, USGS)
  • Boiga irregularis striking (Photo: G. H. Rodda, U.S. Geological Museum)
  • Boiga irregularis head (Photo: G. H. Rodda, U.S. Geological Museum)
  • Boiga irregularis coiled (Photo: G. H. Rodda, U.S. Geological Survey)
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Common name
brown tree snake (English), Braune Nachtbaumnatter (German), culepla (Chamorro, Guam), kulebla (Chamorro, Guam), brown catsnake (English)
Synonym
Coluber irregularis , Merrem in Bechstein 1802
Hurria pseudoboiga , Daudin 1803
Dendrophis , (Ahetula) fusca Gray 1842
Triglyphodon irregulare , Dum�ril, Bibron & Dum�ril 1854
Triglyphodon flavescens , Dum�ril, Bibron & Dum�ril 1854
Pappophis laticeps , Macleay 1877
Pappophis flavigastra , Macleay 1877
Dipsas boydii , Macleay 1884
Dipsas irregularis , Fischer 1884
Dipsas ornata , Macleay 1888
Dipsadomorphus irregularis , Werner 1899
Boiga flavescens
Similar species
Summary
Native island species are predisposed and vulnerable to local extinction by invaders. When the brown tree snake (Boiga irregularis) was accidentally introduced to Guam it caused the local extinction of most of the island’s native bird and lizard species. It also caused \"cascading\" ecological effects by removing native pollinators, causing the subsequent decline of native plant species. The ecosystem fragility of other Pacific islands to which cargo flows from Guam has made the potential spread of the brown tree snake from Guam a major concern.
Species Description
Boiga irregularis is a slender, climbing snake with large eyes and a vertical pupil, giving it improved nocturnal vision (Fritts & Leasman-Tanner 2001). The head is considerably wider than the neck. Markings may be either vague or distinct blotches on a brownish-yellow background. In parts of Australia, blue or red banding on a white background may be seen (Rodda 1999). Black speckling may also be present on some individuals. Brown tree snakes are about 38 centimeters at hatching and may reach three meters long, but are usually one to two meters. they are adept climbers and can crawl through very small openings (USDA-APHIS 2001).

\r\nB. irregularis is rear-fanged and mildly poisonous. The snake’s venom trickles into a bite victim along grooves in the rear fangs; because of the relatively small size and position of the fangs, a brown tree snake must chew to allow the fangs to penetrate the skin (USDA-APHIS 2001). The brown tree snake will readily strike when aggravated, but it does not present a danger to adults. A bite from this snake will not penetrate most clothing, Both constriction and venom are used to help immobilize prey (USDA-APHIS 2001), and babies less than 6 months old may be at risk from both brown tree snake bites and constriction (USDA-APHIS 2001). A young victim of a brown tree snake bite should receive immediate medical attention.

Notes
If visiting or departing Guam, you can help ensure the snake does not leave with you by carefully inspecting your belongings, particularly outdoor goods, when packing. For more information about the brown tree snake, contact the Guam WS office at (671) 635-4400 or the Hawaii WS State office at (808) 861-8576. \r\n\r\n

Any snake sightings on islands thought to lack snakes should be reported immediately to:\r\n\r\n

James Stanford--USGS\r\n
Brown Treesnake Rapid Response Team Coordinator\r\n
Phone (24 hours): 671-777-HISS (4477)\r\n\r\n

Further information on reporting brown treesnake sightings is available at the \r\nUSGS Fort Collins Science Center site.

Lifecycle Stages
Young snakes hatch from eggs in approximately 90 days.
Habitat Description
In Papua New Guinea where it is native, B. irregularis occupies a wide variety of habitats at elevations up to 1200 meters. It is most commonly found in trees, caves, and near limestone cliffs, but frequently comes down to the ground to forage at night (Fritts & Leasman-Tanner 2001). It hides during the day in the crowns of palms, hollow logs, rock crevices, caves and even the dark corners of thatched houses near the roof (Fritts & Leasman-Tanner 2001). Based on frequent mention of this snake in relation to buildings, domestic poultry and caged birds, the snake is common in human-disturbed habitats and second-growth forests (Fritts & Leasman-Tanner 2001). In part of its native range in Indonesia, it is found in tropical evergreen forests, montane forests, lowland tropical forests, mangroves, montane savanna, wet savanna, seasonal dry forests and closed shrubland. It is also found in human-modified environments, such as deforested land, grassland and croplands (coffee, rice, rubber, coconut, tea and maize cultivations). \r\nOn Guam, this secretive, nocturnal, and often arboreal snake is found in all terrestrial habitats, but is especially common in forests and human-modified environments (Rodda et al. 2002). The brown tree snake spends most days coiled in a cool and dark location, such as a treetop or a rotted log; it often takes refuge in Pandanus sp. trees (Hetherington et al. 2008). Snakes sighted in the Northern Mariana Islands occured in freshwater swamp forests, herbaceous wetland vegetation, tropical montane savanna, coastal strand vegetation and mangrove forest and in human-modified environments.
Reproduction
The reproductive characteristics of the brown tree snake are poorly known. The female produces four to 12 oblong eggs, 42 to 47 mm long and 18 to 22 mm wide; they have a leathery shell and often adhere together after the shells dry (Fritts & Leasman-Tanner 2001). The female deposits the eggs in hollow logs, rock crevices and other sites where they are likely protected from drying and high temperatures (Fritts & Leasman-Tanner 2001). Females may produce two clutches per year and the timing may depend on climate and prey abundance (Fritts & Leasman-Tanner 2001). Like other snake species, the female may be able to store sperm and produce eggs over several years after mating (Fritts & Leasman-Tanner 2001).

One puzzling result of brown tree snake reproductive studies is that reproductively active males appear to be relatively rare; this is surprising, because female reproductive activity occurs at all times of year in brown treesnakes (F. J. Qualls & C. P. Qualls Unpub. Data, Aldridge 1996 1998, Rodda \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\net al. 1999c, in Rodda et al. 2002). From an adaptive perspective, one would expect males to be able to take advantage of mating opportunities at whatever time of year they encounter a receptive female. Yet reproductively-active males are relatively rare in samples of brown tree snakes (which are collected primarily with food-baited traps). One possible explanation for this phenomenon might be that snakes that are reproductively active are refractory to trap capture. Snake breeders report that male snakes in general avoid eating while they are in reproductive condition (N. Ford Pers. Comm., in Rodda et al. 2002).

Nutrition
The brown tree snake will eat frogs, lizards, small mammals, birds and birds' eggs. In Papua New Guinea, eggs and chicks are regularly consumed, but mammals are more frequently taken (Fritts & Leasman-Tanner 2001). Having nearly depleted the bird populations on Guam, larger snakes have been found scavenging garbage and even sneaking in to steal a hamburger off the barbeque (Fritts & Leasman-Tanner 2001).

Brown tree snakes shift their diet from smaller exothermic prey to larger endothermic prey as they grow from juveniles to adults (Savidge 1988). This is usually seen as a switch from lizards to birds and mammals. Skinks such as Emoia caeruleocauda and Carlia ailanpalai (itself an invasive species) and geckos such as Lepidodactylus lugubris and Hemidactylus frenatus (which are very abundant in human commensal areas) serve as a superabundant food source for juvenile brown tree snakes in Guam. High densities of introduced vertebrates, in particular, the gecko H. frenatus have allowed the snake to attain the high densities seen there (Rodda Fritts & Conry 1992).

Pathway
The rapid spread of the snake in Guam after 1960 is unexplained. It is plausible that some people might have intentionally spread the snake to suppress rat populations, which were very high on Guam before establishment of the snake (Beardsley 1964, SavidgThe attraction of the brown tree snake to small, dark places (Pendleton 1947, in Rodda Fritts & Conry 1992) leaves little doubt that they are potential stowaways in military and non-military cargo (Rodda Fritts & Conry 1992).The brown tree snake is an excellent climber, using minute irregularities to ascend almost any structure, is extremely efficient at entering small openings and hiding in them for protracted periods and can survive for months without food (Perry et al

Principal source: Rodda et al., 1999; Fritts & Leasman-Tanner, 2001; Mortensen et al., 2008

Compiler: Revision: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)

Review: Dr. Gad Perry, Associate Professor, Conservation Biology Texas Tech University, USA.

Publication date: 2009-08-16

Recommended citation: Global Invasive Species Database (2016) Species profile: Boiga irregularis. Downloaded from http://www.iucngisd.org/gisd/species.php?sc=54 on 03-12-2016.

General Impacts
Reduction in Native Biodiversity:The brown tree snake has decimated Guam’s birds and herpetofauna, causing the local extinction of over half of Guam’s native bird and lizard species as well as two out of three of Guam’s native bat species (Savidge 1987; Rodda & Fritts 1992). Several indigenous or endemic species of lizards have become extinct or engangered because of snake predation (Rodda & Fritts 1992). Guam's 12 forest birds were especially impacted, with 10 species eliminated and the other two severely reduced (Rodda & Savidge 2007). By eliminating native pollinators the brown tree snake has also caused \"cascading\" effects on Guam ecosystems, reducing pollination by lizards and birds and reducing native plant regeneration and coverage as a consequence (Perry & Morton 1999; Mortensen, Dupont & Olesen 2008).

Human Health: This rear-fanged colubrid snake is mildly venomous and poses a potential health hazard to infants and young children. It is responsible for one of every thousand hospital emergency room visits on the island (United States Department of Defense 2008). Envenomation of babies has been reported as relatively frequent (Fritts et al. 1990). Besides the direct effects of brown tree snake bites, there is also the danger of increased disease carried by insects that were previously kept in check by Guam's native lizards and birds (Fritts & Leasman-Tanner 2001). Examples of this include an outbreak of dengue fever carried by mosquitoes and a high rate of infant salmonellosis for several years (Fritts & Leasman-Tanner 2001).

Economic/Livelihoods: Power outages caused by snakes have been a serious problem on Guam since 1978, and the incidence of snake-caused outages continues to cause significant problems. The brown tree snake has caused thousands of power outages affecting private, commercial, and military activities, at one stage averaging once every two to three days. While most of these affect a limited area, some are widespread or island-wide blackouts. Everything from school lighting, computers used by retail outlets, traffic signals to refrigeration of perishable goods are subject to these power interruptions. The costs due to direct damages and lost productivity are conservatively estimated at $1 to 4 million dollars each year (Fritts & Leasman-Tanner 2001; Fritts 2002).

A bad perception of the brown tree snake (although it is not harmful to adults) may cause tourists to avoid Guam in favour of more unspoilt locations. Since tourism is only outranked by U.S. military and government in economic importance on Guam, lost tourism dollars could cause major economic stress (Fritts & Leasman-Tanner 2001). Researchers estimate that if the brown tree snake estabishes in Hawaii tourism losses will amount to USD 0.5 to 1.5 billion (D' Evelyn et al. 2008; Rodda & Savage 2007).

Agriculture: The brown tree snake is reported to be an agricultural pest (Fritts & McCoid 1991, in Engeman et al. 2002). Insect species that are no longer naturally controlled by Guam’s native birds and lizards reduce fruit and vegetable yields (Fritts & Leasman-Tanner 2001). Agriculture has continually declined in importance on Guam since 1945, around when the snake was introduced to the island (Fritts & Leasman-Tanner 2001). Agriculture has continually declined in importance on Guam since 1945, around when the snake was introduced to the island (Fritts & Leasman-Tanner 2001), although additional socio-economic factors were very important in this process.

Management Info
For a detailed account of management information for Boiga irregularis please read: Boiga irregularis (Brown Tree Snake) Management Information. The information in this document is summarised below.\r\n

Preventative measures: In 1993 Wildlife Services (WS) and the US Department of Agriculture began a programme to reduce the potential for snakes to enter Guam's transportation system (see Engeman et al. 2002; Vice et al. 2005b). WS has taken the primary role in this effort through trapping, oral toxicants, fence line searches and the use of BTS detection dog teams (Stanford & Rodda 2007).

Physical Control:
Traps: A variety of modified crawfish or minnow traps have been used on Guam to trap snakes (Rodda et al 1999; Vice et al 2005a). Trapping snakes with live-mouse lures is the principal control technique for this invasive species on Guam (Gragg et al. 2007). It is estimated that approximately 2500 snake traps have been placed on the island (Rodda et al. 2002).

Barriers: Multiple studies have examined the use of barriers for blocking brown treesnakes (Rodda et al. 1998; Perry et al. 2004). Rodda and colleagues (2002) found it possible to create small, predator-free nature reserves using a combination of snake barrier and trapping methods (Rodda et al. 1999a). Campbell (1996, in Rodda et al. 2002), eliminated brown tree snakes from two one-hectare plots and found that lizard species showed a dramatic increase in abundance compared with similar snake-inhabited plots; within a year their numbers roughly doubled. The Campbell barriers brought attention to two acute problems: typhoons and rats. Rats chew holes in all things chewable and Guam is subjected to irregular but severe cyclonic storms which may damage barriers (Rodda et al. 2002).

Chemical: One component of brown tree snake management on Guam is the use of a toxic bait that consists of acetaminophen tablets inserted into a dead newborn mouse, which in turn is placed within a cylindrical polyvinyl chloride bait station suspended above ground or fitted with a tiny parachute so that it drifts into trees (Avery Tillman & Savarie 2004; Savarie et al. 2005; Westbrook and Ramos 2005). Possible hazards to nontarget species, especially the Mariana crow (Corvus kubaryi) which ingests mice, are of concern but appear to be limited (Avery Tillman & Savarie 2004).

Thermal: Brown treesnakes can be killed by excessively cold or hot temperatures, and several studies have examined the use of thermal fumigation. Under normal handling conditions, passive thermal fumigation might have some benefits, but is not a complete solution (Perry & Vice, 2008).

Biological Control:\r\nHistorical evidence shows that the biological control of vertebrates is fraught with unacceptable risk. Cane toads and poisonous red-bellied black snakes may prey on the young of the brown tree snake occasionally but the introduction of either could conceivably cause more problems than it could potentially solve (Caudell et al. 2002).

Integrated Pest Management (IPM):\r\nConservation actions on Guam should be directed towards an improved recruitment via artificial pollination and planting of flora indirectly impacted by the brown tree snake (see Ecology Page Impacts information from Mortensen et al. 2008). Restoring conditions for natural pollination or managing reproduction of vertebrate-pollinated plants is critical in the long-term conservation of native vegetation types on Guam (Mortensen et al. 2008). Efforts are now underway to conserve the few remaining larger areas of uniform forest vegetation, e.g. the conservation action plan Guam Comprehensive Wildlife Conservation Strategy (2005).

Countries (or multi-country features) with distribution records for Boiga irregularis
Informations on Boiga irregularis has been recorded for the following locations. Click on the name for additional informations.
Lorem Ipsum
Location Status Invasiveness Occurrence Source
Details of Boiga irregularis in information
Status
Invasiveness
Arrival date
Occurrence
Source
Introduction
Species notes for this location
Location note
Management notes for this location
Impact
Mechanism:
Outcome:
Ecosystem services:
Impact information
Reduction in Native Biodiversity:The brown tree snake has decimated Guam’s birds and herpetofauna, causing the local extinction of over half of Guam’s native bird and lizard species as well as two out of three of Guam’s native bat species (Savidge 1987; Rodda & Fritts 1992). Several indigenous or endemic species of lizards have become extinct or engangered because of snake predation (Rodda & Fritts 1992). Guam's 12 forest birds were especially impacted, with 10 species eliminated and the other two severely reduced (Rodda & Savidge 2007). By eliminating native pollinators the brown tree snake has also caused \"cascading\" effects on Guam ecosystems, reducing pollination by lizards and birds and reducing native plant regeneration and coverage as a consequence (Perry & Morton 1999; Mortensen, Dupont & Olesen 2008).

Human Health: This rear-fanged colubrid snake is mildly venomous and poses a potential health hazard to infants and young children. It is responsible for one of every thousand hospital emergency room visits on the island (United States Department of Defense 2008). Envenomation of babies has been reported as relatively frequent (Fritts et al. 1990). Besides the direct effects of brown tree snake bites, there is also the danger of increased disease carried by insects that were previously kept in check by Guam's native lizards and birds (Fritts & Leasman-Tanner 2001). Examples of this include an outbreak of dengue fever carried by mosquitoes and a high rate of infant salmonellosis for several years (Fritts & Leasman-Tanner 2001).

Economic/Livelihoods: Power outages caused by snakes have been a serious problem on Guam since 1978, and the incidence of snake-caused outages continues to cause significant problems. The brown tree snake has caused thousands of power outages affecting private, commercial, and military activities, at one stage averaging once every two to three days. While most of these affect a limited area, some are widespread or island-wide blackouts. Everything from school lighting, computers used by retail outlets, traffic signals to refrigeration of perishable goods are subject to these power interruptions. The costs due to direct damages and lost productivity are conservatively estimated at $1 to 4 million dollars each year (Fritts & Leasman-Tanner 2001; Fritts 2002).

A bad perception of the brown tree snake (although it is not harmful to adults) may cause tourists to avoid Guam in favour of more unspoilt locations. Since tourism is only outranked by U.S. military and government in economic importance on Guam, lost tourism dollars could cause major economic stress (Fritts & Leasman-Tanner 2001). Researchers estimate that if the brown tree snake estabishes in Hawaii tourism losses will amount to USD 0.5 to 1.5 billion (D' Evelyn et al. 2008; Rodda & Savage 2007).

Agriculture: The brown tree snake is reported to be an agricultural pest (Fritts & McCoid 1991, in Engeman et al. 2002). Insect species that are no longer naturally controlled by Guam’s native birds and lizards reduce fruit and vegetable yields (Fritts & Leasman-Tanner 2001). Agriculture has continually declined in importance on Guam since 1945, around when the snake was introduced to the island (Fritts & Leasman-Tanner 2001). Agriculture has continually declined in importance on Guam since 1945, around when the snake was introduced to the island (Fritts & Leasman-Tanner 2001), although additional socio-economic factors were very important in this process.

Locations
GUAM
NORTHERN MARIANA ISLANDS
Mechanism
[2] Predation
[1] Disease transmission
Outcomes
[2] Environmental Ecosystem - Habitat
  • [2] Reduction in native biodiversity
[4] Socio-Economic
  • [1] Reduce/damage livestock and products
  • [1] Human health
  • [1] Damage to infrastructures
  • [1] Alteration of recreational use and tourism
Management information
For a detailed account of management information for Boiga irregularis please read: Boiga irregularis (Brown Tree Snake) Management Information. The information in this document is summarised below.\r\n

Preventative measures: In 1993 Wildlife Services (WS) and the US Department of Agriculture began a programme to reduce the potential for snakes to enter Guam's transportation system (see Engeman et al. 2002; Vice et al. 2005b). WS has taken the primary role in this effort through trapping, oral toxicants, fence line searches and the use of BTS detection dog teams (Stanford & Rodda 2007).

Physical Control:
Traps: A variety of modified crawfish or minnow traps have been used on Guam to trap snakes (Rodda et al 1999; Vice et al 2005a). Trapping snakes with live-mouse lures is the principal control technique for this invasive species on Guam (Gragg et al. 2007). It is estimated that approximately 2500 snake traps have been placed on the island (Rodda et al. 2002).

Barriers: Multiple studies have examined the use of barriers for blocking brown treesnakes (Rodda et al. 1998; Perry et al. 2004). Rodda and colleagues (2002) found it possible to create small, predator-free nature reserves using a combination of snake barrier and trapping methods (Rodda et al. 1999a). Campbell (1996, in Rodda et al. 2002), eliminated brown tree snakes from two one-hectare plots and found that lizard species showed a dramatic increase in abundance compared with similar snake-inhabited plots; within a year their numbers roughly doubled. The Campbell barriers brought attention to two acute problems: typhoons and rats. Rats chew holes in all things chewable and Guam is subjected to irregular but severe cyclonic storms which may damage barriers (Rodda et al. 2002).

Chemical: One component of brown tree snake management on Guam is the use of a toxic bait that consists of acetaminophen tablets inserted into a dead newborn mouse, which in turn is placed within a cylindrical polyvinyl chloride bait station suspended above ground or fitted with a tiny parachute so that it drifts into trees (Avery Tillman & Savarie 2004; Savarie et al. 2005; Westbrook and Ramos 2005). Possible hazards to nontarget species, especially the Mariana crow (Corvus kubaryi) which ingests mice, are of concern but appear to be limited (Avery Tillman & Savarie 2004).

Thermal: Brown treesnakes can be killed by excessively cold or hot temperatures, and several studies have examined the use of thermal fumigation. Under normal handling conditions, passive thermal fumigation might have some benefits, but is not a complete solution (Perry & Vice, 2008).

Biological Control:\r\nHistorical evidence shows that the biological control of vertebrates is fraught with unacceptable risk. Cane toads and poisonous red-bellied black snakes may prey on the young of the brown tree snake occasionally but the introduction of either could conceivably cause more problems than it could potentially solve (Caudell et al. 2002).

Integrated Pest Management (IPM):\r\nConservation actions on Guam should be directed towards an improved recruitment via artificial pollination and planting of flora indirectly impacted by the brown tree snake (see Ecology Page Impacts information from Mortensen et al. 2008). Restoring conditions for natural pollination or managing reproduction of vertebrate-pollinated plants is critical in the long-term conservation of native vegetation types on Guam (Mortensen et al. 2008). Efforts are now underway to conserve the few remaining larger areas of uniform forest vegetation, e.g. the conservation action plan Guam Comprehensive Wildlife Conservation Strategy (2005).

Locations
GUAM
NORTHERN MARIANA ISLANDS
UNITED STATES
Management Category
Prevention
Control
Bibliography
88 references found for Boiga irregularis

Managment information
Aguon, Celestino F. Campbell, Earl W., III ; Morton, John M. Efficacy of electrical barriers used to protect Mariana crow nests Wildlife Society Bulletin. 30(3). Fall, 2002. 703-708.
Atkinson, I. A. E. and Atkinson, T. J. 2000. Land vertebrates as invasive species on islands served by the South Pacific Regional Environment Programme. In: Invasive Species in the Pacific: A Technical Review and Draft Regional Strategy. South Pacific Regional Environment Programme, Samoa: 19-84.
Summary: This report reviews available information on the adverse effects of 14 alien vertebrates considered to be �significant invasive species on islands of the South Pacific and Hawaii, supplementing the authors� experience with that of other workers.
Avery, M.L., Tillman, E.A., Savarie, P.J. 2004. Responses of captive fish crows (Corvus ossifragus) to acetaminophen baits and bait stations for brown tree snake (Boiga irregularis) control on Guam. Bird Behavior 16(1-2): 1-6.
Bomford, M., 2003. Risk Assessment for the Import and Keeping of Exotic Vertebrates in Australia. Bureau of Rural Sciences, Canberra.
Summary: Available from: http://www.feral.org.au/wp-content/uploads/2010/03/PC12803.pdf [Accessed August 19 2010]
Boyarski, V.L., Savidge, J.A., Rodda, G.H. 2008. Brown treesnake (Boiga irregularis) trappability: Attributes of the snake, environment and trap. Applied Herpetology 5(1): 47-61.
Clark, L. & Shivik, J. 2002. Aerosolized essential oils and individual natural product compounds as brown treesnake repellents Pest Management Science 58(8): 775-783.
Colvin, B.A., Fall, M.W., Fitzgerald, L.A. & Loope, L.L. 2005. Review of brown treesnake problems and control programs: report of observations and recommendations. Report to Office of Insular Affairs, Honolulu, Hawaii, USA.
D Evelyn, S.T., Tarui, N., Burnett, K. & Roumasset, J.A. 2008. Learning-by-catching: Uncertain invasive-species populations and the value of information. Journal of Environmental Management. 89: 284-292.
Engeman, Richard A; Linnell, Michael A. The effect of trap spacing on the capture of brown tree snakes on Guam International Biodeterioration & Biodegradation. 54(4). December 2004. 265-267.
Engeman , Richard M. and Daniel S. Vice., 2001a. Objectives and Integrated Approaches for the Control of Brown Tree Snakes. Integrated Pest Management Reviews Volume 6, Number 1 / March, 2001
Engeman, Richard M., Daniel S. Vice, George Nelson, Ernest Muna., 2000. Brown tree snakes e?ectively removed from a large plot of land on Guam by perimeter trapping. International Biodeterioration & Biodegradation 45 (2000) 139�142
Engeman, Richard M.; Groninger, N. Paige [Author]; Vice, Daniel S. A general model for predicting brown tree snake capture rates.Environmetrics. 14(3). May 2003. 295-305.
Engeman, Richard M.; Linnell, Michael A.; Aguon, Phillip; Manibusan, Anthony; Sayama, Steven; Techaira, Anthony. Implications of brown tree snake captures from fences Wildlife Research. 26(1). 1999. 111-116.
Engeman, Richard M.; Vice, Daniel S.; York, Darryl; Gruver, Kenneth S. Sustained evaluation of the effectiveness of detector dogs for locating brown tree snakes in cargo outbound from Guam International Biodeterioration & Biodegradation. 49(2-3). 2002. 101-106.
Engeman, R. M.; Vice, D. S., 2001b. A direct comparison of trapping and spotlight searches for capturing Brown Tree Snakes on Guam Pacific Conservation Biology. 7(1). June, 2001. 4-8.
Fritts, T. H. 1987. Movements of snakes via cargo in the Pacific region. Elepaio 47: 17-18.
Fritts, T. H. 1988. The brown tree snake, Boiga irregularis, a threat to Pacific Islands. U.S. Fish and Wildlife Service Biological Reports 88(31). 36pp.
Gee II, David E., pers. comm. 2006. Wildlife Biologist, Guam Division of Aquatic & Wildlife Resources and Guam team member of the Pacific Invasives Learning Network (PILN).
Gragg, James E.; Rodda, Gordon H.; Savidge, Julie A.; White, Gary C.; Dean-Bradley, Kathy; Ellingson, Aaron R. Response of brown treesnakes to reduction of their rodent prey Journal of Wildlife Management. 71(7). SEP 2007. 2311-2317.
IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4.
Summary: The IUCN Red List of Threatened Species provides taxonomic, conservation status and distribution information on taxa that have been globally evaluated using the IUCN Red List Categories and Criteria. This system is designed to determine the relative risk of extinction, and the main purpose of the IUCN Red List is to catalogue and highlight those taxa that are facing a higher risk of global extinction (i.e. those listed as Critically Endangered, Endangered and Vulnerable). The IUCN Red List also includes information on taxa that are categorized as Extinct or Extinct in the Wild; on taxa that cannot be evaluated because of insufficient information (i.e. are Data Deficient); and on taxa that are either close to meeting the threatened thresholds or that would be threatened were it not for an ongoing taxon-specific conservation programme (i.e. are Near Threatened).
Available from: http://www.iucnredlist.org/ [Accessed 25 May 2011]
Johnston, J. J.; Savarie, P. J. [Author]; Primus, T. M.; Eisemann, J. D.; Hurley, J. C.; Kohler, D. J. Risk assessment of an acetaminophen baiting program for chemical control of brown tree snakes on Guam: Evaluation of baits, snake residues, and potential primary and secondary hazards Environmental Science & Technology. 36(17). September 1, 2002. 3827-3833.
Moore, Ignacio T; Greene, Michael J.; Lerner, Darren T.; Asher, Chance E.; Krohmer, Randolph W.; Hess, David L.; Whittier, Joan; Mason, Robert T. Physiological evidence for reproductive suppression in the introduced population of brown tree snakes (Boiga irregularis) on Guam Biological Conservation. 121(1). January 2005. 91-98.
Perry, G., E.W. Campbell, G.H. Rodda & T.H. Fritts. 1998. Managing Island Biotas: Brown Tree Snake Control Using Barrier Technology, Proc. 18th Vertebr. Pest Conf. (R.O. Baker & A.C. Crabb, Eds.). Univ. of Calf.
Perry, G., Rodda, G.H., Fritts, T.H. & Qualls, F.J. 2004. Snake control using barrier technology: a summary of work conducted 1995-2001. Micronesica 37: 177.
Perry, G. & Vice, D. 2008. An evaluation of passive thermal fumigation for brown treesnake control in surface transportation from Guam. In G.W. Witmer, W.C. Pitt, and K.A. Fagerstone (Eds), Managing Vertebrate Invasive Species: Proceedings of an International Symposium (pp. 224-233). USDA/APHIS/WS, National Wildlife Research Center, Fort Collins, CO.
Qualls, Fiona J.; Qualls, Carl P. A simple method of sterilizing male snakes: A potential aid in preventing the spread of brown treesnakes (Boiga irregularis) from Guam. Herpetological Review. 33(3). September 2002. 185-187
Rodda, G.H., Fritts, T.H., Clark, C.S. Gotte, S.W. and Chiszar, D. 1999a. A state-of-the-art trap for the brown treesnake. In G. Rodda, Y. Sawai, D. Chiszar and H. Tanaka (Eds), Problem Snake Management: Habu and Brown Treesnake (pp. 268-284). Ithaca, NY: Cornell University Press.
Rodda, G.H., Fritts, T.H., McCoid, M.J. & Campbell, E.W III. 1999. An overview of the biology of the Brown Treesnake (Boiga irregularis), a costly introduced pest on Pacific Islands. In G.H. Rodda, Y. Sawai, D. Chiszar & H. Tanaka (Eds.), Problem Snake Management: The Habu and the Brown Treesnake. Cornell University Press, Ithaca, NY.
Rodda, G.H., Savidge, J.A; Tyrrell, C.L., Christy, M.T., Ellingson, A.R. 2007. Size bias in visual searches and trapping of brown treesnakes on Guam. Journal of Wildlife Management 71(2): 656-661.
Rodda, G.H., Sawai, Y., Chiszar, D. & Tanaka, H. (Eds.). 1999. Problem snake management: The Habu and the Brown Tree Snake. Ithaca, NY: Comstock Publication Associates, Cornell University Press.
Summary: This book summarizes the state of knowledge as of 1999 - a nice and broad compilation that lists just about everything else of use to that date.
Rodders, Dennis and Stefan Lotters, 2010. Potential Distribution of the Alien Invasive Brown Tree Snake, Boiga irregularis (Reptilia: Colubridae). Pacific Science (2010), vol. 64, no. 1:11�22
Shivik, John A.; Savarie, Peter J.; Clark, Larry. Aerial delivery of baits to brown treesnakes. Wildlife Society Bulletin. 30(4). Winter 2002. 1062-1067.
Summary: Available from: http://www.aphis.usda.gov/wildlife_damage/nwrc/publications/02pubs/shiv022.pdf
[Accsessed ] 10 April, 2009
Stanford, J.W. & Rodda, G.H. 2007. The brown treesnake rapid response team. USDA National Wildlife Research Center Symposia: Managing Vertebrate Invasive Species.
United States Department of Defense. 2008. Report to the Congress: Control of the Brown Tree Snake (BTS).
Summary: Available from: http://www.afpmb.org/docs/bts/TAB%20B%20BTS%20REPORT%20TO%20CONGRESS%20Aug%20FINAL.pdf [Accessed 16 December 2009]
USDA National Agricultural Library., 2008. Species profiles: Brown Tree snake
Summary: The U.S.Geological Survey has assumed a central role in studying the biology of the brown tree snake, the problems it can cause and alternatives for control. USGS researchers are also examining how ecological health is jeopardized on Guam and other islands.
Available from: http://www.invasivespeciesinfo.gov/animals/bts.shtml [Accessed 21 February 2008]
Vice, D.S. & Engeman, R.M. 2000. Brown treesnake discoveries during detector dog inspections following Supertyphoon Paka. Wildlife Damage Management, Internet Center for USDA National Wildlife Research Center - Staff Publications University of Nebraska - Lincoln Year 2000
Vice, D.S., Engeman, R.M. & Vice, D.L. 2005a. A comparison of three trap designs for capturing brown treesnakes on Guam, Wildlife Research 32: 355-359.
Vice, D.S. & Vice, D.L. Characteristics of Brown Treesnakes Boiga irregularis removed from Guam s transportation network Pacific Conservation Biology. 10(4). 2004. 216-220.
Westbrook, C. and Ramos, K. 2005. Under Siege: Invasive Species on Military Bases. National Wildlife Federation.
Wiles, G. J., Bart, J., Beck Jr. R. E., and Aguan, C.F., 2003. Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam�s Avifauna. Conservation Biology, Volume 17, No. 5.
Summary: Impacts of brown tree snake on endemic species in Guam.
General information
Aldridge, Robert D. Arackal, Anna A. Reproductive biology and stress of captivity in male brown treesnakes (Boiga irregularis) on Guam Australian Journal of Zoology. 53(4). 2005. 249-256.
Anon. 2004. Brown tree snake bill advances. Environment & Energy Daily.
Campbell, Steven R. , Mackessy, Stephen P. ; Clarke, Jennifer A. Microhabitat use by Brown Treesnakes (Boiga irregularis): Effects of moonlight and prey Journal of Herpetology. 42(2). JUN 2008. 246-250.
Caudell, Joe N.; Conover, Michael R.; Whittier, Joan . Predation of brown tree snakes (Boiga irregularis) in Australia International Biodeterioration & Biodegradation. 49(2-3). 2002. 107-111.
Christy, Michelle T.; Clark, Craig S. [Author]; Gee, David E. II; Vice, Diane; Vice, Daniel S.; Warner, Mitchell P.; Tyrrell, Claudine L.; Rodda, Gordon H.; Savidge, Fulie A.. Recent records of alien anurans on the Pacific Island of Guam Pacific Science. 61(4). OCT 2007. 469-483.
Conroy, P. J. 1988. High nest predation by brown tree snakes on Guam. Condor 90: 478-482.
Daniel S. Vice Mikel E. Pitzler., 2000. Brown Treesnake Control: Economy of Scales. USDA National Wildlife Research Center Symposia Human Conflicts with Wildlife: Economic Considerations University of Nebraska - Lincoln Year 2000
Engbring, J. and Fritts, T. H. 1988. Demise of an insular avifauna: the brown tree snake on Guam brown tree snake on Guam. Transactions of the Western Section of the Wildlife Society of the Wildlife Society 24: 31-37.
Esselstyn, Jacob A.; Amar, Arjun; Janeke, Dustin. Impact of post-typhoon hunting on Mariana fruit bats (Pteropus mariannus) Pacific Science. 60(4). OCT 2006. 531-539.
Fancy, Steven G.; Snetsinger, Thomas J.. What caused the population decline of the Bridled White-eye on Rota, Mariana Islands? Studies in Avian Biology.(22). 16 March, 2001. 274-280.
Freeman, A.A. 2004. House panel to vet bill on invasive snakes. Environment & Energy Daily.
Fritts, T.H. 2002. Economic costs of electrical system instability and power outages caused by snakes on the Island of Guam. International Biodeterioration & Biodegradation 49:93-100.
Fritts, Thomas H.. Economic costs of electrical system instability and power outages caused by snakes on the Island of Guam International Biodeterioration & Biodegradation. 49(2-3). 2002. 93-100.
Fritts, T.H. & Rodda, G.H. 1998. The role of introduced species in the degradation of island ecosystems: a case history of Guam. Annual Review of Ecology and Systematics 29: 113�140.
Hetherington, Thomas E.; Coupe, Brad [Author]; Perry, Gad; Anderson, Nancy L.; Williams, Joseph B. Diurnal refuge-site selection by Brown Treesnakes (Boiga irregularis) on Guam Amphibia-Reptilia. 29(2). MAY 2008. 284-287.
ITIS (Integrated Taxonomic Information System), 2004. Online Database Boiga irregularis
Summary: An online database that provides taxonomic information, common names, synonyms and geographical jurisdiction of a species. In addition links are provided to retrieve biological records and collection information from the Global Biodiversity Information Facility (GBIF) Data Portal and bioscience articles from BioOne journals.
Available from: http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=174206 [Accessed 21 February 2008]
James W. Stanford Gordon H. Rodda, 2007. The Brown Treesnake Rapid Response Team. USDA National Wildlife Research Center Symposia Managing Vertebrate Invasive Species University of Nebraska - Lincoln Year 2007
Loope, Lloyd L.; Howarth, Francis G.; Kraus, Frederick; Pratt, Thane K. Newly emergent and future threats of alien species to Pacific birds and ecosystems. Studies in Avian Biology.(22). 16 March, 2001. 291-304.
Mathies, Tom; Miller, Lowell A. Cool temperatures elicit reproduction in a biologically invasive predator, the brown treesnake (Boiga irregularis). Zoo Biology. 22(3). 2003. 227-238.
McCoid, M. J. 1991. Brown tree snake (Boiga irregularis) on Guam: a worst case scenario of an introduced predator. Micronesica 3: 63�69.
McCoid, M. J., Stinson, D. W. 1991. Recent snake sightings in the Mariana Islands. Elepaio 51: 36-37.
Mortensen, H.S. Dupont, Y.L., Olesen, J.M. 2008. A snake in paradise: Disturbance of plant reproduction following extirpation of bird flower-visitors on Guam. Biological Conservation 141(8): 2146-2154.
Perry, G. 1998. Brown treesnake update. Aliens 8: 6�7.
Perry, G. & Morton, J.M. 1999. Regeneration rates of woody vegetation of Guam�s Northwest Field following major disturbance: land use patterns, feral ungulates, and cascading effects of the brown treesnake. Micronesica 31: 125�142.
Perry, G. & Vice, D. 2009. Forecasting the risk of brown tree snake dispersal from Guam: a mixed transport-establishment model. Conservation Biology 23: 992-1000.
Plentovich, Sheldon; Morton, John M.; Bart, Jonathan; Camp, Richard J.; Lusk, Michael; Johnson, Nathan; Vanderwerf, Eric. Population trends of Mariana Crow Corvus kubaryi on rota, commonwealth of the Northern Mariana Islands Bird Conservation International. 15(2). JUN 05. 211-224.
Reptiles Database, 2010. Boiga irregularis Merrem, 1802
Summary: Available from: http://reptile-database.reptarium.cz/species.php?genus=Boiga&species=irregularis [Accessed September 8 2010]
Rodda, G.H., Fritts, T.H., Conroy, P.J. 1992. Origin and population growth of the brown tree snake, Boiga irregularis, on Guam. Pacific Science 46: 46-57.
Rodda, G.H., Fritts, T.H., Perry, G. and Campbell, E.W. III. 1998. Managing island biotas: can indigenous species be protected from introduced predators such as the brown treesnake? Transactions of the 63rd North American Wildlife Natural Resources Conference: 95-108. Perry, G., Rodda, G.H., Fritts, T.H. & Qualls, F.J. 2004. Snake control using barrier technology: a summary of work conducted 1995-2001. Micronesica 37: 177.
Rodda, G.H., Fritts, T.H. & Reichel, J.D. 1991. The distributional patterns of reptiles and amphibians in the Mariana Islands. Micronesica 24: 195-210.
Rodda, G.H. & Savidge, J.A. 2007. Biology and impacts of pacific island invasive species. 2. Boiga irregularis, the Brown Tree Snake (Reptilia: Colubiridae). Pacific Science 61(3): 307-324.
Savarie, Peter J. , John A. Shivik., Gary C. White., Jerome C. Hurley., Larry Clark., 2001. Use of Acetaminophen for large Scale Control of Brown Treesnakes. Wildlife Damage Management, Internet Center for USDA National Wildlife Research Center - Staff Publications University of Nebraska - Lincoln Year 2001
Savarie, Peter J. & Kenneth L. Tope., 2004. Potential Flotation Devices for Aerial Delivery of Baitsto brown Treesnakes. Wildlife Damage Management, Internet Center for USDA National Wildlife Research Center - Staff Publications University of Nebraska - Lincoln Year 2
Savarie, Peter J., Tom C. Mathies & Kathleen A. Fagerstone., 2007. Flotation Materials for Aerial Delivery of Acetaminophen Toxic baits to Brown Treesnakes. USDA National Wildlife Research Center Symposia Managing Vertebrate Invasive Species University of Nebraska - Lincoln Year 2007
Savarie, Peter J.; Wood, W. Scott; Rodda, Gordon H.; Bruggers, Richard L.; Engeman, Richard M. Effectiveness of methyl bromide as a cargo fumigant for brown treesnakes International Biodeterioration & Biodegradation. 56(1). JUL 2005. 40-44.
Savidge, J. A. 1987. Extinction of an island forest avifauna by an introduced snake. Ecology 68: 660-668.
Savidge, J.A. 1987. Extinction of an Island Forest Avifauna by an Introduced Snake. Ecology 68(3): 660-668.
Savidge, J. A. 1988. Food habits of Boiga irregularis, an introduced predator on Guam. Journal of Herpetology 22(3), 275-282.
Savidge, J. A. 1988. Food habits of Boiga irregularis, an introduced predator on Guam. Journal of Herpetology 22: 275-282.
Savidge, Julie A.; Qualls, Fiona J.; Rodda, Gordon H. Reproductive biology of the brown tree snake, Boiga irregularis (Reptilia : Colubridae), during colonization of Guam and comparison with that in their native range Pacific Science. 61(2). APR 2007. 191-199.
Shwiff, Stephanie A., Karen Gebhardt, Katy N. Kirkpatrick, and Steven S. Shwiff, 2010. Potential Economic Damage from Introduction of Brown Tree Snakes, Boiga irregularis (Reptilia: Colubridae), to the Islands of Hawai�i. Pacific Science (2010), vol. 64, no. 1:1�10
USDA-APHIS (United States Department of Agriculture - Animal and Plant Health Inspection Services). 2001. The Brown Tree Snake Factsheet.
Summary: Available from: http://www.aphis.usda.gov/publications/wildlife_damage/content/printable_version/fs_wsbtsnake.pdf [Accessed 16 December 2009]
Vice, D.S., Linnell, M.A. & Pitzler, M.E. 2005b. Draft summary of Guam s outbound cargo handling process: preventing the spread of the brown treesnake. U.S. Department of Agriculture, Animal Plant Health Inspect. Service, Wildlife Service, Barrigada, Guam.
Whittier, Joan; Macrokanis, Conrad; Mason, Robert T. Morphology of the brown tree snake, Boiga irregularis, with a comparison of native and extralimital populations Australian Journal of Zoology. 48(4). 2000. 357-367.
Wiles, Gary J.; Bart, Jonathan; Beck, Robert E. Jr.; Aguon, Celestino F.. Impacts of the brown tree snake: Patterns of decline and species persistence in Guam s avifauna. Conservation Biology. 17(5). October 2003. 1350-1360.
Wiles, Gary J.. Records of communal roosting in Mariana Crows Wilson Bulletin. 110(1). March, 1998. 126-128.
Contact
The following 5 contacts offer information an advice on Boiga irregularis
Campbell,
Earl
Hawaii
Organization:
U.S. Dept. of Agriculture, NWRC
Address:
National Wildlife Research Cebter, Hawaii Field Station, PO Box 10880, Hilo, HI 96721, U.S.A.
Phone:
+1 808 9614482
Fax:
+1 808 9614776
Kraus,
Fred
Vertebrate Zoologist
Organization:
Department of Natural Sciences
Address:
Bishop Museum, 1525 Bernice St. Honolulu, HI 96817 USA
Phone:
(808) 848-4118
Fax:
(808) 847-8252
Perry,
Gad
Organization:
Assistant Professor, Conservation Biology University of Texas at Austin
Address:
Goddard Hall 202C
Phone:
(806) 742-2842
Fax:
Rodda,
Gordon
U.S. (off Guam)
Organization:
U.S. Dept. of Interior, USGS
Address:
4512 McMurry Ave., Fort Collins, CO 80525, U.S.A.
Phone:
+1 970 2269471
Fax:
+1 970 2269230
Vice,
Dan
Guam
Organization:
U.S. Dept. of Agriculture
Email:
Address:
1060 Route 16, Suite 103C, Barrigada Heights, Guam 96913, U.S.A.
Phone:
+1 671 6354400
Fax:
+1 671 6354401