Rats

New Zealand has been the world leader in the eradication of invasive mammalian predators from offshore islands. Today, the focus for invasive predator management is shifting to larger landscapes; big inhabited islands or the mainland itself. The most cost-effective approach in the long term will be to eradicate the predators from those areas, ensuring permanent freedom for vulnerable and threatened native biodiversity to recover or be reintroduced. Island eradication technologies cannot always be employed on the mainland (e.g. aerial brodifacoum), so a new approach is required.

BBC website news article - Flood hit South Indian state of Kerala 11 people died of leptospirosis; After floods expect to see water-borne diseases like cholera, typhoid, diarrhoea, hepatitis and rat fever

Short website news article about rat eradication on Chagos Islands in the Indian Ocean and how bird populations increase without rat predation increasing nutrients from bird guano into the coral reefs; cites letter article in Springer Nature - Seabirds enhance coral reef productivity and functioning inthe absence of invasive rats, Nichaolas A.J. Graham, Shaun K. Wilson, Peter Carr, Andrew S. Hoey, Simon Jennings, M. Aaron MacNeil https://doi.org/10.1038/s41586-018-0202-3

Big South Cape Island (Taukihepa) is a 1040 ha island, 1.5 km from the southwest coast of Stewart Island/Rakiura, New Zealand. This island was rat-free until the incursion of ship rats (Rattus rattus) in, or shortly before, 1963, suspected to have been accidentally introduced via local fishing boats that moored at the island with ropes to the shore, and were used to transport the mutton birders to the island.

Rodent eradications are a key island restoration activity to counteract extinction and endangerment to native species. Despite the widespread use of brodifacoum as a rodenticide for island restoration, there has been little examination of its potential negative effects on native reptiles. Here we examined the survival of two endemic insular lizard populations before, during and after a brodifacoum-based rodent eradication using a mark-recapture study.

The introduction of invasive rats, goats, and rhesus macaques to Desecheo National Wildlife Refuge, Puerto Rico led to the extirpation of regionally signifi cant seabird colonies and negatively impacted plant and endemic reptile species. In 2012, following the successful removal of goats and macaques from Desecheo, an attempt to remove black rats using aerially broadcast rodenticide and bait stations was unsuccessful.

Rat eradication techniques developed in New Zealand are a proven method for removing invasive rodents from islands worldwide. This technology moved rapidly from ground-based bait station operations to aerial application of rodenticides. Rat eradications on tropical islands using similar methods, have not always been as successful as those in temperate regions. As most previous eradications in the Caribbean have been on islands smaller than 50 ha, the eradication of black rats (Rattus rattus) from 207 ha Dog Island was a significant increase in size.