Objectives and integrated approaches for the control of brown tree snakes: An updated overview

Abstract

a b s t r a c tAfter its inadvertent introduction to Guam, the brown tree snake (Boiga irregularis, BTS) extirpated most of the island's native terrestrial vertebrates, presented a health hazard to small children, and had considerable economic ramifications. Management of BTS is aimed at a number of objectives, the foremost of which has been to deter its dispersal from Guam to other locations. Further objectives include reclaiming areas on Guam as snake-free for reintroduction of native wildlife, to protect small sensitive sites on Guam from BTS intrusion (e.g, power stations, bird nesting sites), to contain and capture stowaway BTS incoming to vulnerable destinations, and to control incipient populations in other areas beyond their native range. A number of control tools have been developed, and the efficacy of each control method depends on the situation to which it is applied. Integration of control methods provides the most efficacious results for all objectives. Here, we outline the different objectives for managing BTS, and the tools and methods available for BTS management. We complete the picture by describing which tools and methods are best suited to accomplish each management objective.Published by Elsevier Ltd.

Behavioral differences following ingestion of large meals and consequences for management of a harmful invasive snake: A field experiment

“…Results of this invasion included the extirpation or extinction of nearly the entire native forest avifauna (Savidge, ; Wiles, Bart, Beck, & Aguon, ), with cascading ecological and economic consequences (e.g., Perry & Morton, ; Rogers, Hille Ris Lambers, Miller, & Tewksbury, ; Rogers et al., ), and impacts on domestic poultry production, tourism, and human health (Fritts & McCoid, ; Fritts, McCoid, & Haddock, ; Rodda & Savidge, ). Because Guam is a major hub for commercial and household goods throughout the Pacific, economic impacts are increased by the cost of developing, testing, and implementing tools and strategies to reduce brown treesnake abundance and preventing accidental transportation of brown treesnakes to other Pacific islands such as Saipan, Rota, Tinian, and Hawai'i (Clark, Clark, & Siers, ; Engeman & Vice, ; Pimentel, Lach, Zuniga, & Morrison, ).…”

“…These factors have also been indicated to influence brown treesnake movement characteristics (Santana‐Bendix, ; Tobin, Sugihara, Pochop, & Linnell, ; Siers, Reed, & Savidge, ; Christy et al., ). If brown treesnakes decrease movement and foraging during digestion, this will have implications for the effectiveness of various control tools that typically rely either on visual detection by human searchers or response of foraging snakes to lures or baits (e.g., Christy et al., ; Clark et al., ; Engeman & Vice, ; Lardner et al., ; Tyrell et al., ).…”

Using DNA to Identify the Source of Invasive Mongooses, Herpestes auropunctatus (Carnivora: Herpestidae) Captured on Kaua‘i, Hawaiian Islands

“…For example, Guam practices extensive biosecurity for preventing brown tree snakes (Boiga irregularis) from leaving Guam in cargo. The security measures utilize an integrative pest management plan that includes the use of detection dogs to survey cargo for snakes, trapping and use of poison baits around ports, and spotlighting fence lines for hand-removal (Engeman et al 2018). New Zealand is known for their strong stance on island biosecurity, which includes the prevention of pest species introductions into the country, rapid-response for invasive species removal following detection (Broome 2007), and keeping off-shore islands predator free (Russell et al 2008).…”

“…New Zealand is known for their strong stance on island biosecurity, which includes the prevention of pest species introductions into the country, rapid-response for invasive species removal following detection (Broome 2007), and keeping off-shore islands predator free (Russell et al 2008). Part of what makes these biosecurity efforts attractive and effective is that the various techniques and methodologies that are used are periodically tested and validated (Russell et al 2008, Engeman et al 2018. DNA analyses can help elucidate invasion pathways and thus direct managers to increase biosecurity at weak links.…”

Spatial dynamics of habitat use informs reintroduction efforts in the presence of an invasive predator

“…Until such techniques are refined, predator control within fenced units remains the most sustainable means of reintroducing birds on Guam. Given the cost of such intensive management, it is critical to determine the spatial scale at which actions should be implemented and which habitats should be targeted (Engeman & Vice, ; Scofield, Cullen, & Wang, ). Diurnal location data are often used by managers to create such management plans.…”