Is it a Rabbit or a Rodent: The Truth about the Amami Rabbit (Pentalagus furnessi)

Amami Rabbit (Pentalagus furnessi) Fun Facts

Common Name: Amami Rabbit or Ryukyu Rabbit (in Japanese: Amami Kuro Usagi or “Amami wild black rabbit”)

Scientific Name: Pentalagus furnessi

Size and Appearance: Just as its Japanese name suggests, the defining characteristic of an Amami rabbit is its distinct black color. Usually, they are about have a meter long where males are slightly shorter and smaller than females. The female rabbit also tends to be slightly heavier at 2.5 kg and males weigh 2.2 kg on average.

Typically, they have small heads and large bodies which make them look like a cross between a rodent and a rabbit. They have short tails and short ears as well.

Life Span: What is interesting about this species of animal is that its longevity is still currently unknown. There are very limited data to suggest the length of their life. Since there are also thousands of these in the wild, it is quite difficult to keep track of individual animals.

Habitat: This particular species of rabbit can be found in both the young and mature forests of Amami Island and Toku-no Island. They use grass and other herbs for their cover and protection. Often times, the female rabbit burrows holes in the ground to protect their young. These cover the hole with a combination of plant and soil material. Since these rabbits are nocturnal animals, they are often found resting in burrows, tree hollows, and shallow caves during the day.

Distribution: Based on the latest survey, there are roughly 2,000 to 4,000 Ryukyu rabbits in Amami island. Then, there are less than 300 rabbits in Toku-no Island. Majority of the population of the Pentalagus furnessi is indigenous to Amami-shima while the minority of its population can be found in Toku-no-Shima. These are the only places in the world where this kind of rabbit can be found.

Current Status: Although there are about 2,000 rabbits living in Amami island, the species is still considered as endangered. The fact that its population lives in a singular location may be a determining factor for its current status. Any disruptive events that may take place in the area can easily wipe out the entire population of Amami rabbits.

 Details about the Pentalagus furnessi

How were they discovered?

According to some historical records, the Pentalagus furnessi scientific name was first coined and described in the year 1900s by a scientist named Stone. This means that its existence has been recorded and observed since. There is no other place in the world where the Amami rabbit could be found except in these two small islands of Japan.

What is interesting about this particular species of rabbit is the fact that it is titled as a “living fossil”. This is due to the fact that it was discovered to exhibit very little mutation and evolution (both physical and physiological) compared to pre-historic rabbits that existed in Asia millions of years ago. It is believed to have died out from other islands or have cross-bred to become the modern rabbits of today. As they have died out, this kind of prehistoric rabbit remains only on two small Japanese islands.

By Momotarou2012 [CC BY-SA 3.0 (], from Wikimedia Commons

On top of these facts, the oldest recorded fossil found on the Pentalagus furnessi could be dated back to the ice age which is roughly 20,000 years ago. The fossil consisted of a skull and a few bones, was identified using dental information compared to living Amami rabbits of today.

One of the latest studies about the population of the Amami rabbis was done by Ken Sugimura which studied the presence of fecal pellets in the island. They have used this information to estimate the total number of Ryukyu rabbits living at present. This particular study was done to ensure the proper preservation of the Amami rabbit population.

What makes them different from other rabbits?

This particular species of rabbit looks almost similar to a rodent. It would look like a small rodent’s head fit in a large rabbit’s body. It has a small, beady pair of eyes which is either black or red. It has a short pair of ears which sets it apart from other rabbit species.

The Amami rabbit has short hind legs and short feet. It also has a very long and large body. However, despite its size, it is not easily seen out in the open because of its dark, wooly coat which blends with the surroundings. The typical color of an Amami rabbit is dark brown or black with reddish-brown fur on the sides.

The average weight of an Amami rabbit is 2.3kg where the female rabbit is slightly larger than the male rabbit. The largest Amami rabbit ever recorded in history weighs 2.9 kg while the smallest was 2.0 kg. Another distinct characteristic of the Amami rabbit would be their large and heavy-duty claws. Since these animals are known to burrow for protection, they have very strong claws that could withstand impact to small stone and even hard soil. Their claws are described to be straight and long on their front legs and clawed in their hind legs.

Where do they live?

Both the Amami and Tokuno islands are deeply forested and are very mountainous. Forests in these islands are also considered as rainforests because of the high rate of annual precipitation it experiences. There are also tall, broad-leafed trees in the area which protects the soil from excessive sunlight.

The Ryukyu rabbits are known to inhabit forested areas and benefit from both young and mature forests. They get their diet and create their homes from materials produced from both forest types. They also love acorns and pampas grass for their diet which is why they prefer mature forests during severe seasonal changes. They also frequent newer growths in forests for young herbs, perennial plants, and grasses all throughout the year.

By Image Science and Analysis Laboratory, NASA-Johnson Space Center. "The Gateway to Astronaut Photography of Earth." (NASA Photo ID : ISS019-E-12520) [Public domain], via Wikimedia Commons

During the day, they are known to burrow into the soil and create temporary covers from soil and undergrowth. They use their large feet to tamper their burrows and make it sturdier in case a heavy predator accidentally steps on the cover. They are also commonly found in grasslands which are lush with ferns and perennial plants. They are also known to commonly inhabit locations near bodies of water.

How do they behave?

These animals are known to be a nocturnal species where they remain hidden during the day. They also make sounds and vocalizations that these animals use as signals. Some signals indicate that danger is looming like when predators and humans enter their home range. Other signals indicate that the mother has returned to the nest. There are also sounds made for mating. Certain sounds are made by vocalization while other signals are created by pounding their hind limbs on the ground.

These animals are very shy and often scramble at the sight of larger animals. They like keeping to themselves and are very isolated animals. Their home range also does not include other individuals especially those of same females. The home range of a male can overlap with a female or another male. But this is not true for the female kind. What is interesting is that since these animals live on an island, there are certain sightings that claim these animals swimming or frolicking in the water.  

What do they eat?

Just like any other rabbit species, Ryukyu rabbits are herbivores that mostly feed on vegetation from the forests. They are known to consume herbaceous plants, shrubs, and grasses. They are found to eat sprouts, shoots, and other young plants. One of their favorite snacks would be pampas grass which has soft, thin blades and stems – easy for both chewing and digestion.

On the other hand, during harsh weather, Amami rabbits are known to feed on acorns, stems, bark, and even twigs of shrub plants. They are also found to eat nuts of different plants and cambiums of hard stems or twigs.

How do they reproduce?

There are no specific data regarding the specific mating patterns of the Amami rabbits. There is no known indication whether these animals are monogamous or not. They can be very promiscuous because home ranges of male rabbits often overlap with female rabbits. However, the peak of the mating season happens twice every year, once between March and May and another between September and December.

One way for these animals to attract a mate is for a male rabbit to approach a female. During this time, the male rabbit uses its nose to lift the female’s abdomen and bit its legs during copulation. A typical litter of neonates is about one to three young.

There had been attempts in breeding Amami rabbits for the past decades. However, breeding in captivity was only able to produce one offspring at every birth. The most successful is by the Kagoshima Hirakawa zoo which successfully produced about 11 offsprings in a span five years.

What is interesting about these rabbits is the fact that female rabbits often have two burrows. One is for their personal living space and daily activity while the other is for their birthing and nesting. Usually, during the day the mother leaves their young in a secured burrow. However, after three to four months of nursing, the female block their young from the burrows to force them to live independent lives.

Predation of the Amami Rabbit

The presence of predators in Amami island creates danger in the population of this rabbit species. Among its most common predator would be the Java mongoose which is quite abundant in the area. The animal is also preyed upon by both feral cats and dogs that have reached the islands from human habitation. On top of that, the wild is also home to a number of other creatures that can harm the population of the Amami rabbits. This would include native snakes and poisonous frogs.

Threats to the life of the Amami Rabbit

In the IUCN Red List of Threatened Species, the Amami rabbit is considered endangered. Although it is not considered under the top priority status and is not critically endangered, there are still some efforts that need to be made for its dwindling number to improve. It is also considered as endangered on the US Federal List of Endangered Species.

The number one cause of the decline in the population of the Amami rabbit would be the presence of human settlement in both Amami and Tokuno islands. It was recorded to be widely hunted in the early 1900s up to the 1920s until it was declared as a natural monument in Japan.

By Chung Bill Bill ( [CC BY 2.0 (], via Wikimedia Commons

However, even though hunting of the Amami rabbit stopped, its death from traps still did not. This is why in the mid-1960s, it was declared as a “special natural monument” fining any individual which would cause harm to the animal.

Of course, the massive deforestation in the island has also limited the population of the Amami rabbits. Since they require both new and mature forests to survive, the destruction of mature forests in the island will create a severe damage to its number.

Conservation efforts to protect the Amami Rabbit (Pentalagus furnessi)

Other than the declaration of its special natural monument status, there had been ongoing efforts to conserve the population of the Amami rabbit. Since they are known to inhabit only a specific location in the world, it is quite easy for their numbers to deteriorate. The problem is that there may be mandates to ban the hunting and trapping of these animals, but there are no specific declarations against the damaging of their natural habitat.

This is why current conservation efforts focus on creating laws, or regulations, that will include the preservation of the environment for the benefit of the Amami rabbits. It was researched, in fact, that rotating the logging of forests could potentially reduce the decline of the Amami rabbit’s population.

Some scientists like Yamada in 2003 has created an extensive research on the life, population, and conservation of the Amami rabbit. There are a number of newly created references that explore on possible methodologies to improve the number of the Amami rabbit and research on its breeding in captivity.