Taxonomic notes: Section empty

This species occurs throughout subtropical and tropical eastern and northern Australia (Trembath and Fearn 2008). It is known from the Torres Strait islands of Waiben, Muralug, Ngurupai, Badu, Mua, Dauan, Saibai, and Mer (Lavery et al. 2012).  It is found throughout New Guinea except for elevations above 1,400 m asl and the majority of West Papua Province in Indonesian New Guinea. It has been recorded on the Indonesian island of Sulawesi and the Moluccan Kei and Aru islands. In Papua New Guinea it occurs on the Milne Bay Province islands of Trobriand, Kiriwina, Goodenough, Fergusson and Normanby. It is found throughout the Bismarck Archipelago and Admiralty islands (O’Shea 1996). In the Solomons islands it is present on Bougainville, Shortland, Mono, Choiseul, Ranongga, Vella lavella, New Georgia, Tetepare, Vangunu, Isabel, Guadalcanal, Ngela and Malaita (McCoy 2006). It was introduced to Guam shortly after the Second World War, and is now found throughout the island.

This is a common species, with a likely stable population.

This species inhabits a wide variety of habitats including lowland and low montane primary and secondary rainforest, coastal mangrove swamps, rocky outcrops, and also modified areas including regrowth areas, plantations, rural gardens and urban areas (O’Shea 1996). This species is mostly arboreal but will also venture onto the ground. It is nocturnal and crepuscular and is an active predator (Allison et al. 1998). It has a very broad diet including a variety of vertebrate prey birds, small mammals, reptile and lizards (O’Shea 1996). A willingness to consume carrion indicates a flexible trophic ecology, allowing rapid exploitation of any available food resources (Trembath and Fearn 2008). This species is oviparous and produces between 2 – 11 eggs. Savidge et al. (2007) noted it may be possible for this species to reproduce asexually. If so, this would further reduce the minimum requirements for establishing extralimital populations of brown tree snakes from one previously mated female to one juvenile female, or even one egg.

Natusch and Lyons (2012) noted the trade of this species from Merauke in Indonesian New Guinea. Thirty-three individuals were recorded at wildlife traders between September 2010 - April 2011. There is no quota for this species. 

It is unlikely that any major threats are impacting this species. Considerable effort is taken to extirpate it from its introduced range in Guam, where it is highly invasive and has been responsible for the extinctions of several endemic bird species.

No direct conservation measures are needed for the species. This species occurs in many protected areas in New Guinea and presumably more in the rest of its range.
There is a need to control introduced populations in Guam, and to prevent it from spreading via air or sea traffic to other vulnerable islands, such as Hawaii.

• 2.2 Invasive/problematic species control

Boiga irregularis has been assessed as Least Concern. It has a wide distribution including eastern Indonesian islands, New Guinea, Bismarck Archipelago and the Solomon islands. It has been introduced onto Guam where it is become a serious threat to the native fauna. It is abundant throughout its range, occupies a wide range of habitats including modified areas and is not affected by any major threats. It is present in many protected areas in New Guinea. Further research on this species ecology is required to assist with bio-control programs.

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• Wanger, T.C., I. Motzke, S. Saleh and Iskandar, D.T. 2011. The amphibians and reptiles of the Lore Lindu National Park area, Central Sulawesi, Indonesia. Salamandra 47(1): 17-29.