Peters, D.; L. Wilson, S Mosher, J. Rohrer, J. Hanley, A. Nadig, M. Silbernagle, M. Nishimoto, and J. Jeffrey. Small Indian mongoose – management and eradication using DOC 250 kill traps, first lessons from Hawaii
Small Indian mongoose – management and eradication using DOC 250 kill traps, first lessons from Hawaii
D. Peters1, L. Wilson2, S Mosher3, J. Rohrer3, J. Hanley4, A. Nadig5, M. Silbernagle4,M. Nishimoto6, and J. Jeffrey7 1Department of Conservation, P.O Box 10420, Wellington, New Zealand.
Introduction The small Indian mongoose (Herpestes auropunctatus) Methods is a catastrophic invasive predator of the West Indies, Hawaiian Islands, South America, Fiji, Mafia Island and A collaborative programme to test the DOC 250 island habitats of Africa, Asia and Europe (Long 2003; traps was set up between the New Zealand Department Warren and Conant 2007). They impact upon and cause of Conservation, US Fish and Wildlife Service, Haleiwa the extinction of many species of birds, mammals, and (Oahu, Hawaii), US Fish and Wildlife Service, Honolulu insects (Warren and Conant 2007). (Oahu, Hawaii), US Fish and Wildlife Service, Kealia Pond (Maui, Hawaii) and the Oahu Army Natural Resource To date in Hawaii, the most common control method Program, Schofield Barracks (Oahu, Hawaii), USA. for mongoose is cage live trapping. This method requires skilled and intensive labour as traps must be checked daily DOC 250 kill traps were set in current best practice and captured animals either dispatched on site with firearms wooden trap boxes (Fig. 1) in the initial humane test and at or offsite in carbon dioxide chambers. These labour each of the three sites where field trials were undertaken. intensive methods impact upon management decisions particularly regarding the size and scope of control projects. Less labour reliant and more cost effective tools are needed to enable control or eradication of mongooses over larger areas, such as on islands and in large mainland reserves. The DOC 250 kill trap has passed National Animal Welfare Advisory Committee (NAWAC) humane guidelines for use against mustelids in New Zealand (Poutu and Warburton 2005). These traps are always set in trap boxes and are triggered by the weight of an animal stepping onto a treadle. It has been developed for use with four pest species in New Zealand, including the ferret (Mustela furo), which is comparable in size and behaviour to the mongoose. Given similarities between small Indian mongooses and ferrets, DOC 250 traps should show equivalent humane efficacy for both species. A preliminary controlled test was therefore organised in 2007, to determine whether the DOC 250 kill trap could conform to NAWAC requirements and render small Indian mongoose irreversibly unconscious within three minutes of being caught. This paper presents the outcome of the preliminary humane test and results from three subsequent, small- scale field trials that used DOC 250 kill traps to target and Fig. 1 DOC 250 kill trap being set in a current best practise successfully kill small Indian mongoose in Hawaii. trap box designed to catch small Indian mongoose.
Pages 225-227 In: Veitch, C. R.; Clout, M. N. and Towns, D. R. (eds.). 2011. Island invasives: eradication and management. IUCN, Gland, Switzerland. 225 Island invasives: eradication and management
Table 2 Results from Trial 2, DOC 250 kill traps Date Traps checked Captures Sat 16 May 2009 yes 1 Sun 17 May 2009 no Mon 18 May 2009 yes 6 Total 7
Trial 1: Jack Jeffrey’s property – Hilo, Hawaii Island Six Doc 250 trap sets were placed 20 - 50 metres apart in rough grassland surrounded by wooded farmland and tree plantings. Each trap was baited with tinned sardines and activated for two nights from 02 - 04 April 2007. Trial 2: James Campbell/Ki’i Wildlife Refuge – Oahu Fig. 2 DOC 250 kill trap baited with sardines. The small Island Indian mongoose has been humanely killed. Fourteen DOC 250 trap sets were spaced 50 - 70 metres apart along access ways within the 45 hectare refuge, composed of wetland with introduced grasses. Traps were baited with tinned sardines on 16 - 18 May and checked Each trap box was baited with tinned sardine or cat twice during the three night trapping period. crunchies (commercially available cat food in the form Trial 3: Kealia Pond National Wildlife Refuge – Maui of cereal based pellets) and all traps were checked and Island serviced after between one and three days at all sites. Twelve trap sites, comprising a paired arrangement The objectives of this trial were to determine whether of a standard Doc 250 trap-set placed 1 - 3 metres from DOC 250 traps are: 1) capable of humanely killing small a Tomahawk live cage trap, were established at 20 – 50 Indian mongoose; 2) capable og trapping mongooses in metre intervals, over an area of marshland and introduced the wild; and 3) more effective than Tomahawk live-traps grasses. All traps were baited with cat crunchies placed in in controlling mongoose numbers in the wild. NAWAC a bait jar with wire mesh lid. This paired trap trial ran for guidelines were used as the humane standards for this a period of four months from 14 June to 17 October 2009, trial, as there was a clear mandate to do so from the two with trap checks and servicing being undertaken every day. governments involved. In this trial, the Tomahawk traps were checked every day, Preliminary Humane Test: James Campbell/Ki’i in accordance with NAWAC humane guidelines. The DOC Wildlife Refuge, Oahu Island. 250 traps may be checked less often, as these humane kill- Two captive small Indian mongoose were trapped traps comply with NAWAC guidelines, regardless of time under controlled conditions in a DOC 250 kill trap set in between trap-checks. the marsh/ introduced grass area of James Campbell/Ki’i Wildlife Refuge on 26 March 2007. Both animals were immediately rendered irreversibly unconscious. This was determined by measuring the palpebral reflex, and time Table 3 Results from Trial 3, DOC 250 and Tomahawk cage to heart-stop, from the moment of trapping. The cause of trap, paired trial. death in both cases was multiple skull fractures (Fig. 2). This result confirmed the hypothesis that DOC 250 kill Session Date DOC 250 Cage trap traps would humanely dispatch Small Indian mongoose 1 14 – 20 June 2009 0 0 within the NAWAC guidelines and provided the confidence 2 21 – 27 June 2009 0 0 for field trials to proceed. 3 28 June – 4 July 2009 1 1 4 5 – 11 July 2009 4 0 5 12 – 18 July 2009 0 1 6 19 – 25 July 2009 0 2 Table 1 Results from Trial 1, DOC 250 kill traps, on the 7 26 July – 1 Aug 2009 0 0 Jeffrey property, Hilo 8 2 – 8 Aug 2009 3 0 Mongoose Date Sex Age class 9 9 -15 Aug 2009 0 0 1 02/04/07 Male Adult 10 16 – 22 Aug 2009 1 0 2 02/04/07 Female Adult 11 23 – 29 Aug 2009 0 0 3 02/04/07 Female Adult 12 30 Aug – 5 Sept 2009 0 0 4 02/04/07 Female Adult 13 6 – 12 Sept 2009 1 0 5 02/04/07 unknown unknown 14 13 – 19 Sept 2009 0 0 8 03/04/07 Male Adult 15 20 – 26 Sept 2009 3 0 9 03/04/07 Male Adult 16 27 Sept – 3 Oct 2009 1 0 10 03/04/07 Female Adult 17 4 – 10 Oct 2009 0 0 11 03/04/07 Male Adult 18 11 – 17 Oct 2009 0 0 12 04/04/07 Male Adult Total 15 4
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Results Conclusion Trial 1: Jack Jeffrey’s property – Hilo, Hawaii Island This study confirms that DOC 250 traps in protective One trap malfunctioned and has been discounted. boxes provide a new and more efficient tool for the Results are based on five operative traps set for two nights. management of small Indian mongoose than current Five mongooses were caught each night, i.e. ten mongooses methods utilizing cage traps. This, however, is merely a in total (Table 1). Each mongoose was killed through start. Formal independent humane accreditation should extensive skull fractures in the same efficient manner as now be sought to add mongoose to the list of DOC 250 the two mongooses used in the preliminary humane test.. approved target species. More comprehensive research and testing should also be undertaken to ascertain the Trial 2: James Campbell/Ki’i Wildlife Refuge – Oahu most appropriate strategies to apply when deploying this Island equipment in the field. Additional collaborations, such as A total of seven mongooses were caught in fourteen those undertaken during this study, would be a positive traps set for four nights (Table 2). All were killed by skull way to achieve these goals. fracture injuries as previously described. Trial 3: Kealia Pond National Wildlife Refuge – Maui ACKNOWLEDGEMENTS Island We particularly thank Jack Jeffrey and Gretchen Grove Nineteen mongooses were caught during this trial; for offering their property at Hilo for one of the field fifteen in DOC 250 kill traps and four in Tomahawk cage trial sites. Thanks also go to Bruce Thomas, who was a traps (Table 3). particularly helpful reviewer of this paper.
Discussion REFERENCES The preliminary humane test and three field trials Brown, K. 2003. Identifying long-term cost-effective approaches to stoat showed conclusively that DOC 250 kill traps, secured and control: a review of sixteen sites in 2002. DOC Science Internal Series set correctly in current best practice wooden boxes, are 137. Department of Conservation, Wellington, New Zealand, 26 pp. extremely effective at catching and humanely killing small Long, J.L. 2003. Introduced mammals of the world: their history, Indian mongoose. distribution and influence. CSIRO Publishing, Collingwood, Australia, 589 pp. It is interesting to note that mongooses were much more inclined to push through two small, offset apertures and get Mc Murtrie, P.; Edge,K.-A.; Crouchley, D. and Willans, M. 2008. Resolution island operational plan: stoat eradication. Department of caught in a DOC 250 trap set in the close confines of an Conservation, Invercargill, New Zealand. enclosed wooden box, than to freely enter the wide open door of a Tomahawk cage trap. This may be due to the Poutu, N. and Warburton, B. 2005. Effectiveness of the DOC 150, 200 and 250 traps for killing stoats, ferrets, Norway rats, ship rats and similarity between enclosed trap boxes and natural burrows hedgehogs. Unpublished report, Landcare Research Contract Report and crevices, which are natural dwellings for small Indian LC0405/109 mongooses. Warren, S.T. and Conant, S. 2007. Biology and impacts of Pacific island DOC 250 traps are lightweight and cost-effective, with invasive species. 1. A worldwide review of effects of the small Indian potential to effectively manage mongoose populations in mongoose, Herpestes javanicus (Carnivora: Herpestidae). Pacific Hawaii. Best-practice methods for their use have been Science 61(1): 3-16. well developed in New Zealand. These procedures include a formalised maintenance schedule when using DOC 250 traps, to ensure that they continue to perform and comply with humane requirements (DOC Ferret control – kill trapping current best practice guidelines, 2005). Effective kill traps do not require daily checking, an advantage which allows managers to better utilise labour and maximise cost effectiveness. Early indications from this project suggest that use of DOC 250 traps will enable control and/or eradication of mongoose when applied in “landscape style” trapping operations (e.g., 1000 ha – 21,000 ha), similar to successful projects in New Zealand such as the Whenuakite Kiwi Care Project (Coromandel) and the Resolution Island Stoat Eradication Project (Fiordland). Both projects are based on proven, current, best practice methodologies (Brown 2003; McMurtrie et. al. 2008). Potential gains for conservation that have been made through the trials in Hawaii are a direct consequence of collaboration between several Government agencies in New Zealand and Hawaii and the cooperation and assistance of local landowners. The pooling of technical expertise combined with local knowledge of target and non-target species, local conditions and community requirements enabled effective project planning, and provision of practical support in undertaking the field trials.
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