rense.com

Mystery Disease Kills
Northwest Trek Rabbits

By Kris Sherman
The Olympian Online
3-11-7

Nine pygmy rabbits died at Northwest Trek near Eatonville during the past month as an unexplained disease swept through the endangered population.
 
Trek officials said the deaths constituted about half of the stock, which was being bred and reared in captivity for eventual release into the wild.
 
The cause of the rabbits' deaths is unknown, but "the situation is being handled as a highly contagious, acutely lethal disease," according to a news release.
 
They were of normal weight and eating well before their deaths, the release said.
 
There "were no visible signs of distress or abnormal behavior within hours" of their deaths.
 
Daily treatment The remaining rabbits were moved indoors and isolated in a clinic, where they're getting daily medical treatment.
 
The sudden deaths canceled Trek's plans to release some of the animals into Washington's Columbia Basin later this month.
 
Trek is one of several partners in the Pygmy Rabbit Recovery Program led by the State Department of Fish and Wildlife, the news release said.
 
The Oregon Zoo and Washington State University also participate. Trek was scheduled to release at least 5 rabbits.
 
Animals from Oregon and WSU will be set free in Douglas County as planned Tuesday [13 Mar 2007], the news release added.
 
Wildlife officials announced this week they planned to release 23 of the captively bred animals. They are to be placed in artificial burrows until they can dig their own.
 
The Columbia Basin Pygmy Rabbit is listed on the state and federal endangered species lists. To ensure the survival of some pygmy rabbits, animals from the Columbia Basin stock were crossbred with Idaho pygmy rabbits, according to a news release from the wildlife service.
 
The Trek rabbits, part of the breeding and rearing program, were not on public display.
 
http://www.theolympian.com/130/story/69116.html
 
 
From Joseph P. Dudley, Ph.D fnjpd@uaf.edu Research Associate Institute of Arctic Biology - University of Alaska Fairbanks Department of Earth Science - University of Alaska Museum
 
"Pygmy Rabbit (_Brachylagus idahoensis_) is listed as an endangered species in the state of Washington, and on the Federal Endangered Species List. Idaho lists it as a State Species of Concern. This rabbit very small, and typically brown to slate gray. Its ears have a white margin and it has a small tail. It has a very small and depressed population size and is threatened by habitat loss and predation as well as some introduced diseases. While a few rabbits remain in the wild, most of the remaining population has been placed in 2 captive breeding programs. Probably less than 50 rabbits of this subspecies remain.
 
"The smallest rabbit species in North America, the pygmy rabbit measures 9.2-11.6 inches (23.5-29.5 cm) in length, weighs a slight 0.88-1.02 lbs (398-462 g), and is able to fit in the palm of a hand. Unlike other rabbit species, the pygmy rabbit digs its own burrows in deep, loose soil. They are dependent upon sagebrush for food, comprising 98 percent of their winter diet and a good portion of their spring and summer diet. Mortality, chiefly from predation, is high for both juveniles (an estimated 50 percent don't survive the 1st 5 weeks) and also the species in general, which has a mortality rate of up to 88 percent per year. Predators include weasels, coyote, badgers, bobcats, raptors, and humans, as many hunters can't distinguish them from other rabbit species.
 
 
It is suggested that areas of tall sagebrush, a specialized habitat requirement, can be promoted by disturbances such as ungulate grazing and perhaps even by the burrowing and feeding activities of the rabbits themselves. Relatedly, more research needs to be conducted on how cattle grazing affects key habitat for the pygmy rabbit. Though the historical population and range of the pygmy rabbit is unclear, evidence suggests it was significantly larger than at present.
 
This decline is primarily due to habitat loss and fragmentation through development, agricultural conversion, and sagebrush burning to promote grasses for livestock forage. The current population total is similarly unclear, as some states (such as Washington) have active surveying programs while others have virtually none. In severe danger of extinction, the Washington population has declined from an estimated 250 rabbits in 1995 to a current estimate of zero. Several small populations known to exist 6 years ago are now extirpated due to wildfire and disease.
 
Recently, the Washington Department of Fish and Wildlife (WDFW) has initiated a captive-breeding program with hopes of revitalizing the population. There are 6 rabbits currently in captivity and they are hoping to find a total of 20 for the program. Originally planning on crossbreeding with Idaho pygmies, the idea was scrapped in favor of preserving the Washington sub-species when it was found the 2 are genetically different. Strategies to enhance pygmy rabbit habitat and population numbers outlined in the Washington State 1995 recovery plan are many and include: monitoring, determining population trends through burrow surveys, developing techniques for estimating numbers, researching the effects of grazing, protecting the population through fire management, keeping track of relative abundance of predators, enhancing existing habitat, and creating new suitable habitat and habitat corridors."
 
Indeed with so few of this species, the deaths at the captive center are quite alarming.
 
There is not enough information here to understand the clinical signs of the illness or the deaths to completely understand what is happening to the animals. We will hope for speedy recovery and for more information from an authoritative source.
 
A close up of a pygmy rabbit may be seen at: http://www.oregonzoo.org/Newsroom/2005%20releases/images/rabbit.jpg and at: http://en.wikipedia.org/wiki/Image:BRACHYLAGUS_IDAHOENSIS.jpg
 
Portions of this commentary have been extracted from: http://www.pacificbio.org/ESIN/Mammals/PygmyRabbit/pygmyrabbit.html
 
- Mod.TG]
 
 
Patricia A. Doyle DVM, PhD
Bus Admin, Tropical Agricultural Economics
Univ of West Indies
 
Please visit my "Emerging Diseases" message board at:
http://www.emergingdisease.org/phpbb/index.php
Also my new website:
http://drpdoyle.tripod.com/
Zhan le Devlesa tai sastimasa
Go with God and in Good Health


Disclaimer






MainPage
http://www.rense.com


This Site Served by TheHostPros