The use of mechanical traps, compressed carbon dioxide and rodenticides are being evaluated as means of controlling and eradicating mongooses and rodents in Hawaii's native ecosystems and wildlife refuges as part of a draft federal environmental impact statement.
Methods to effectively control mongooses and rodents in urban and agricultural areas exist but need to be adapted for use in conservation areas, the U.S. Fish and Wildlife Service said. The federal agency is continuing to develop a draft programmatic EIS to control and eradicate non-native species that kill and eat native birds and plants and their seeds.
Mongooses and rodents have caused extinctions and severe declines of many native species in Hawaii, including the Oahu elepaio, Oahu tree snails and native palms, the Fish and Wildlife Service said.
Indian mongooses, like those pictured above, were introduced to Hawaii in 1883 by the sugar industry in a failed attempt to control rats. Federal and state agencies are working on plans to eradicate mongooses and rodents from sensitive native ecosystems.
Lucknow Zoological Garden photo
The agency has reopened its comment period for the public to weigh in on its draft programmatic EIS to evaluate methods to control and eradicate rodents and mongooses while protecting native wildlife and plants. The new comment period deadline is April 7. Those who already submitted comments during the first comment period from June 30 to Oct. 28 do not need to resubmit their comments.
An official with the Fish and Wildlife Service on Oahu said the agency reopened the public comment period to align with the state's approval process. The Fish and Wildlife Service and the state Department of Land and Natural Resources Division of Forestry and Wildlife each have their own regulatory structure. The two agencies, the co-leads, will work together on the draft programmatic EIS.
They will hold joint talk story sessions with the community; the dates will be announced at a later time.
The draft programmatic EIS being developed will not initiate any specific action or project, but will be used for informational and planning purposes to improve and facilitate rodent and mongoose control on federal, state and private lands, the Fish and Wildlife Service said.
There are no native rodent species in Hawaii. The rodents introduced to the Hawaiian Islands include the Norway rat, black rat, Polynesian rat and house mouse.
The Indian mongoose was introduced only on Hawaii island, Maui, Molokai and Oahu, the Fish and Wildlife Service said. It has no natural predators in Hawaii.
In 1883, the mongoose was first brought to Hawaii island, then to Maui, Molokai and Oahu. The brown carnivorous mammal with a long body and tail that is native to Africa and Asia was introduced to the islands by sugar industry officials to control rats in the cane fields, according to the Hawaii Native Species Council. The introduction was made without any scientific testing or much knowledge about mongooses.
As it turned out, mongooses are active during the day while rats are night creatures.
The Fish and Wildlife Service said it did not have numbers on the mongoose population in Hawaii. A DLNR official also was not able to provide mongoose population data.
The methods to eradicate and control rodents and mongooses to be analyzed include mechanical traps that kill the animal and multikilling devices that could use carbon dioxide gas. Also to be analyzed will be the application of vertebrate toxicants, including rodenticides diphacinone, chlorophacinone and brodifacoum. Depending on the location and circumstances, rodenticides could be distributed by hand, aerial methods or other techniques, such as placing the bait in plastic or cloth bags in the canopy of trees or into shrubs.
The Fish and Wildlife Service said that it only will employ rodenticides currently registered for use in the U.S. for agriculture and/or conservation purposes.
Currently, methods of rodent and mongoose control include using live and kill traps, multikilling devices and diphacinone in bait stations. Diphacinone has been used in bait stations to protect Hawaii's native species since the 1990s, according to the Fish and Wildlife Service.
The draft proposal seeks to:
* Increase the effectiveness of rodent and mongoose management in the main Hawaiian Islands and make more efficient use of limited financial resources.
* Develop techniques for an integrated pest management approach to eradicate rodents from uninhabited islands within the main Hawaiian Islands and from other U.S. Pacific Islands within the National Wildlife Refuge System.
* Avoid adverse impacts to human health, safety, the environment and cultural rights, practices and resources.
Comments regarding the draft programatic EIS may be sent:
* Electronically at www.regulations.gov, follow the instructions for submitting comments on Docket No. FWS-R1-ES-2015-0026.
* By mail to Public Comments Processing, Attn: FWS-R1-ES-2015-0026; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; MS: BPHC; 5275 Leesburg Pike; Falls Church, VA 22041-3803.
More information can be found at www.fws.gov/pacificislands/nativerestoration.
For further information, contact Mary Abrams, field supervisor for the Pacific Islands Fish and Wildlife Office, by phone at (808) 792-9400 or fax at (808) 792-9581. If a telecommunications device for the deaf is required, call the Federal Information Relay Service at (800) 877-8339.
* Melissa Tanji can be reached at firstname.lastname@example.org.