Saving the Columbia Basin Pygmy Rabbit – Iain Dunn

Saving the Columbia Basin Pygmy Rabbit – Iain Dunn

Photo courtesy of U.S. Fish and Wildlife Service

Who is this little bunny?

The incredibly cute Columbia Basin Pygmy Rabbit happens to be the smallest species of rabbit in all of North America. Not only is this little critter cute, but also it is very resourceful, as they are the only rabbit that digs their own burrows. For over 100,000 years, this pygmy rabbit has lived along a stretch of land all the way from northern Oregon to Central Washington, called the Columbia Basin. What distinctly makes this rabbit unique from other pygmy rabbits, is the fact that it was separated roughly 10,000 years ago from the rest of the population, causing genetically different species. These rabbits thrive in the Great Basin’s semiarid shrub steppe, as well as other regions between mountains in the western United States. Normally, pygmy rabbits are located amongst sagebrush (especially the denser, taller areas). Since the pygmy rabbit digs its own burrows, it also prefers regions with soils that are more loose, to grant ease in digging the burrows.

This map depicts the Columbia Basin outlined in red, along with potentially habitable area in green

Up-close look at the Columbia Basin

The scientific name for the Columbia Basin Pygmy Rabbit is Brachylagus idahoensis, and it in the Leporidae family (which includes hares and rabbits). When I said the pygmy rabbit was small, I meant it—it weighs in at approximately 375g to 500g, and measures approximately 23.5 to 29.5 centimeters long. The females tend to be on the longer end of the spectrum, while males tend to be on the shorter end. Every year they molt their fur. Their color is mostly a grayish brown color, while their stomachs are off-white, and their extremities are brown. They have small ears (3.5cm to 5.2 cm) and small tails too (1.5cm to 2.4cm). These tiny attributes are part of what make the pygmy rabbit a distinct species from other rabbits, along with its grayish color and missing white fur on its tail.

When did these critters become known as endangered?

The Columbia Basin Pygmy Rabbit became an endangered species in 2001, when an emergency regulation was enacted. Then in 2003, the pygmy rabbit was entirely listed as endangered.

"Shrub Steppe" courtesy of U.S. Fish and Wildlife Service 

Why did the pygmy rabbit become endangered in the first place?

The #1 cause of the pygmy’s population decline is most likely attributed to the development of new agriculture lands, which destroyed the pygmy’s shrub steppe environment. This lack of habitable environment, along with the pygmy’s small population caused the little rabbit to truly become endangered. Not only was the small population an issue due to the fact that there were few remaining—the remaining few had slim genetic diversity since they inbred with each other repeatedly. There are five threats specifically listed in the pygmy’s recovery plan:

1. Destruction or vast modification of the pygmy’s natural habitat due to crop production

2. Accidentally harming the pygmies due to recreational hunting and scientific trappings

3.     Diseases due to the large number of parasites pygmies carry, which are vectors for transmission; as well as predation from other animals

4.     Lack of regulation for the habitable pygmy area

5.     Natural causes, such as storms or fires

So how many of these cuties are still out there?

In early 2004, the Columbia Basin saw its last wild population of pygmy rabbits, and they became extirpated. After the Columbia Basin Pygmy Rabbit was declared as an endangered species, a captive breeding program was started in 2001 by the Washington Department of Fish and Wildlife. In 2003, this effort to expand the population was furthered when a cross-breeding strategy was developed; this was done by capturing pygmy rabbits from Idaho under the same taxonomic classification, and then “inducing” controlled matings. 20 of these adorable cross-bred pygmies were released into the central Washington part of the Columbia Basin in March, 2007. Unfortunately, none of these pygmies survived to see the summer of 2008. Since the first round of pygmies were unsuccessful, new approaches were adopted and implemented in the summer of 2011:

Photo courtesy of Oregon Zoo

•      More releasing events of cross-bred pygmies
•     Capturing and relocating wild pygmy rabbits not of Columbia Basin origin, into the same areas as the program released cross-bred pygmies
•    Efforts to partially control breeding in the field
• Better protection at the time of release

Fortunately, these new approaches have proved to be successful, and by the end of July 2012, three facilities operating the pygmy rabbit captive breeding ended their programs.

What were the steps of the recovery plan?

The pygmy rabbit’s recovery followed a phased approach. The phases were as follows:

1.     Remove threats to the pygmies and their habitat

2.     Reintroduce a stable amount of pygmies to their natural habitat

3.     Protect the established pygmies

Photo courtesy of Oregon Zoo

The ultimate goal is to classify the Columbia Basin Pygmy Rabbit as threatened species, rather than an endangered species. This will be done through continuing to adjust and implement the recovery steps as needed; to ensure the pygmy population remains at a stable level that is distributed appropriately.

You can help!

The pygmy rabbit’s conservation is mainly in the hands of biologists, but you can abstain from hunting in shrub steppe habitats to ensure the safety of its inhabitants. However, you can get involved and volunteer at your local environmental and/or animal welfare centers! As well as do your research on the pygmy rabbit and other endangered species. Educate yourself on this important topic by doing in-depth research, so that you can have a deeper understanding of the issue through looking at a wide-variety of informational sources.

More resources: 

To begin your deeper self-understanding and perspective on this topic, included is a link and video to more information on the Oregon Zoo’s recovery efforts:

 Oregon Zoo's Success

Works Cited

U.S. Fish and Wildlife Service. 2012. Recovery Plan for the Columbia Basin Distinct Population Segment of the Pygmy Rabbit (Brachylagus idahoensis). Portland, Oregon. ix + 109 pp.