The small Indian mongoose (Herpestes auropunctatus) on Adriatic Islands: impact, evolution, and control

ABSTRACT One cause of declines and extinctions of island species is carnivore introduction. Four carnivores, including the small Indian mongoose (Herpestes auropunctatus), are on the IUCN’s list of 100 of the World\u27s Worst Invasive Alien Species. My thesis summarizes global patterns of carnivore introductions and examines ecological, evolutionary, and management impacts of this mongoose. I study abundances of reptiles and amphibians on mongoose-infested and mongoose-free islands in the Adriatic Sea to determine if factors other than mongoose presence can account for abundance differences. For several reptiles and amphibians, the mongoose is implicated as causing differences. Additionally, I assess species abundance in the small mammal community and activity times of introduced ship rats (Rattus rattus) on the same islands. The mongoose is implicated in a shift in rat activity times, but it is difficult to separate mongoose impacts on small mammal abundance from rat impacts. To manage introduced carnivores, we can exclude, control, or eradicate them. I review literature data on mongoose eradication and control campaigns. I compiled a list of all islands with known mongoose populations and focused on assessing successes, failures, and challenges. The mongoose has been eradicated only on six very small islands. Management at low levels by various techniques has been attempted on many islands, with variable success. On almost all islands of introduction, the mongoose has no potential competitors of similar size. However, on three Adriatic islands where the mongoose was introduced, a similar-sized native carnivore, the stone marten (Martes foina), is present, while on one Adriatic island the small Indian mongoose is the sole carnivore. To see if character displacement occurs in the mongoose when the marten is present, and vice-versa, I examined size variation in the diameter of the upper canine tooth (the prey-killing organ) and skull length in these two species on these islands. Character displacement in both traits was evident for the mongoose but not the marten. Lastly, I developed a simulation model to examine genetic consequences of serial introductions of the small Indian mongoose and found that the potential for population genetic data to determine introduction pathways and sequences is limited

Impact of the introduced small Indian mongoose (Herpestes auropunctatus) on abundance and activity time of the introduced ship rat (Rattus rattus) and the small mammal community on Adriatic islands, Croatia

The small Indian mongoose (Herpestes auropunctatus) is one of the world’s 100 worst invasive species (IUCN 2000). It has negative impacts on several small mammals on islands where it was introduced. We assess the abundance of small mammal populations and the activity time of introduced ship rats (Rattus rattus) on three mongoose-infested and three mongoose-free islands in the Adriatic Sea, Croatia. We set up three transects on each island with a trapping system consisting of 30 small live traps to capture small mammals under 30 grams and 30 larger traps to capture ship rats and mongooses, on each transect. Our results support an already large but mostly speculative literature that suggests inability of the small Indian mongoose to reduce high abundances of introduced R. rattus. Further, we suggest that the low abundance of native small mammals is probably not solely caused by the mongoose but also by high R. rattus populations on all six islands. In addition, we provide evidence that R. rattus has changed its activity time to become more nocturnal on mongoose-infested islands, possibly to avoid predation by the mongoose. As R. rattus became more nocturnal, the diurnal mongoose may have become the main predator on amphibians, reptiles, and poultry

Control of ferrets using 1080 and PAPP in baits and a resetting toxin delivery device

Ferrets (Mustela furo) are widespread in pastoral habitats and are considered a vertebrate pest because they prey on native birds. Also, ferrets are carriers of bovine tuberculosis (TB, Mycobacterium bovis), and TBfree New Zealand currently controls ferrets by labour-intensive and costly trapping. A Lincoln University research programme, 'Pest Control for the 21st Century', funded by the Ministry of Business, Innovation and Employment seeks to advance more humane and effective tools for vertebrate pest control. As a vital part of this programme the new toxin para-aminopropiophenone (PAPP) is being developed for multiple vertebrate pests. With our partners (Connovation Ltd), we have developed a self-resetting delivery device, the Spitfire, which sprays 800 mg of toxic paste onto a pest’s belly. Both PAPP and 1080 have been trialed in a Spitfire for ferrets. Ferrets were found to groom the paste from their bellies and consume a lethal dose. We have also trialed encapsulated PAPP delivered in minced beef to ferrets. Encapsulation prevented vomiting, allowing a lethal concentration of PAPP to be absorbed across the gut. We achieved mortality in 14/15 (93%) ferrets in laboratory trials and field trials are planned. The goal of this research is to provide information on the effectiveness of these new tools to enable registration, and to add to the toolbox of control methods currently used for ferret control

Development of Re-Setting Toxin Delivery Devices and Long-Life Lures for Rats

Introduced rats continue to have a major impact on biodiversity around the world, and improved control techniques are required to avoid further extinctions. We are trialing re-setting toxin-delivery systems (Spitfires) targeting a range of predators, including rats. The rat Spitfire works by firing 800 mg of a toxic paste onto the belly of the rat as it passes through a tunnel; the device then resets. When the rats groom the paste from their fur, they ingest the toxin. Each Spitfire is capable of approximately 100 doses and is fitted with a counter and a delay mechanism. We trialed 0.55% 1080 paste in the Spitfire and 15 of 15 wild Norway rats and 14 of 15 black rats died. Further trials are planned with a range of toxins to allow flexibility of use. Resetting devices that are expected to work for long periods without being serviced also require long-life lures. Preliminary trials showed urine and scats from female Norway rats were attractive to both male and female Norway rats. The volatile components from these and further trials will be identified to aid in developing a long-life lure. The long-term, effective control of introduced rats will require a range of toxins with different modes of action, a number of different delivery systems, and long-life lures

Development of re-setting toxin delivery devices for stoats and rats

Rats and stoats continue to have a major impact on biodiversity in New Zealand, and improved control techniques are required to avoid further extinctions. A resetting toxin delivery device (Spitfire) is being developed as part of a programme entitled 'Pest Control for the 21st Century', funded by the Ministry of Business, Innovation and Employment. The Spitfire works by firing a paste containing a toxin on to the belly of stoats and rats as they pass through a tunnel. The device then resets. When the stoats and rats groom the paste from their fur, they ingest the toxin. Each Spitfire is capable of approximately 100 doses and is fitted with a counter and a delay mechanism. The first successful field trial of the stoat Spitfire was undertaken in the Blue Mountains, West Otago in late 2013. Stoat abundance was significantly reduced but technical problems meant the trigger mechanism had to be re-designed. Para-aminopropiophenone (PAPP), the toxin used for the stoat trial, is not lethal enough for rats, so 1080, Zinc phosphide, cholecalciferol, C+C (cholecalciferol + coumatetralyl) and sodium nitrite are being investigated as alternative toxins for the rat Spitfire. Field trials are planned for both stoats and rats using Spitfires in 2014/15