Columbia Basin Pygmy Rabbits are the world’s smallest rabbits, and also the rarest. As adults they usually weigh less than a pound. The rabbits live in sagebrush communities. In the wild they eat almost nothing but sagebrush in the winter, in the summer they eat a more varied diet. Their litters contain 2 to 6 kits that are born in spring or summer; in these breeding seasons they can have 2 to 4 litters of kits.
Columbia Basin Pygmy rabbits are extinct in the wild. Their decline is attributed to predation and habitat loss due to agriculture and wildfires. The last 14 were taken in the 1990’s from their home of the Columbia Basin in Washington State to a captive breeding program. In the captive breeding program they were not breeding well, partially due to inbreeding. Since then they have been bred to the Idaho Pygmy Rabbit in an effort to increase the numbers, which has proved successful. The Oregon Zoo has a strong captive breeding program. They had a total of 73 bunnies (kits) in one year. They tag the ears of the kits with colored dye to tell them apart.
The Amami Rabbit, also known as the Ryukyu Rabbit, is a rare species found on two islands, Amami Oshima and Tokuno-shima, in Japan. The Amami Rabbit is an ancient breed that more closely resembles primitive rabbits than modern ones. It has short legs, round body, curved claws, dark fur, and is nocturnal. Also, the ears are significantly smaller than modern rabbits and hares. Unlike modern rabbits with litters of six or more kits, the Amami Rabbit rarely has more than one kit per litter and only breed twice per year. This makes it slow to reproduce. Unlike all but one of the 50 rabbit species the Amami Rabbit can make calling sounds, a high-pitched chirping similar to a pika.
The Amami Rabbit is endangered due to hunting, deforestation, and killing by domestic animals. The hunting has stopped because in 1921 the Japanese government gave the rabbit protection, and it is now classified as a Japanese National Monument. The major threat to it now is habitat loss due to deforestation for logging as the rabbit makes its home in the underbrush of forests. Domestic animals like cats and dogs, as well as mongooses are major predators of the slow-moving primitive rabbits.
In 2008 Amami Rangers for the Nature Conservation obtained a photograph of a feral cat carrying a dead rabbit in its mouth, fur and bones have been found in cat and dog droppings as well. This prompted discussions on how to better control these invasive species.
The Volcano Rabbit is the world’s second smallest rabbit. It has small round ears, short legs, and thick, soft fur. It is found on the slopes of volcanoes in Mexico, and now currently resides only on Iztaccihutl, Pelado, Popocatapetl, and Tlaloc volcanoes. It is one of only two rabbit species to make calling noises, high-pitched sounds while thumping its feet on the ground. The rabbit is nocturnal and lives in the underbrush of the pine forests between 2800 and 4250m in elevation.
The most serious threat to the rabbits is habitat degradation and target shooting. Hunting of the rabbit is now illegal under Mexican law, but it is hard to enforce. The rabbits’ habitat is being burned for agriculture, due to the rich volcanic soils, and overgrazing by cattle.
here are currently plans to increase the numbers of these rabbits. This includes the creation of two protected areas, Izta-Popo and Zoquiapan National Parks, but habitat loss still occurs near and encroaches into these areas. The IUCN has called for the creation of habitat corridors between the national parks and a better understanding of the rabbits’ lives. There are also captive breeding programs at the Jersey Zoo, UK, Los Coyotes Park, and the Chapultepec Zoo in Mexico City. But, it is doubtful whether these captive bred rabbits could ever be reintroduced into the wild populations.
As far as being farm animals, these sheep are excellent. They work well as wool sheep because they do not require shearing, they cast(shed) their wool each spring. The wool is highly prized by hand spinners for its soft texture and wide color range of browns and creams. Their meat is also starting to enter the specialty meat market as a delicate alternative to mutton. They are also an excellent means for managing pasture land. They will eat Scots broom, which is an invasive species in many areas, berry vines, and many grasses that other domesticated animals find unpalatable. They are often used as an alternative to herbicides and bulldozers for reclaiming land that has been overrun by brambles, poison oak, and other noxious weeds.
One population, the Hirta population, has remained unmanaged and as such is a good data set for scientific studies. This population meets many of the Hardy-Weinberg requirements including no immigration/emigration and no pressure to evolve due to predators.
Recently the population has come under the scientific radar because it appears to be shrinking. Each of the more recent generations has been smaller than their parents. Recent studies have shown that this trend and the variation around the trend are primarily consequences of environmental variations, due to climactic changes, and not evolution. The environmental changes have resulted in a reduction in lamb growth rates as well as less of a need for the large fat stores of the older generations which were needed for the harsh winters. These winters are becoming less harsh, thus the sheep have less need to build these fat stores.