What kind of animal is the Tokyo shrew? We will explain its characteristics, ecology, and habitat. Please note that although the name is Tokyo, the area where you actually live is completely different. This rat is extremely rare and is listed as an endangered species.
What is the Tokyo shrew? About basic status
The Tokyo shrew is a mammalian mole belonging to the genus Shrew, in the order Truececalidae and family Shrewidae. The scientific name is Sorex minutissimus hawkeri. It is an extremely small animal with a body length of only 45-49mm, a tail length of about 27-31mm, and a weight of about 1.5-1.8g.
| Japanese（和名） | トウキョウトガリネズミ |
| English（英名） | Hawker’s least shrew |
| scientific name(学名) | Sorex minutissimus hawkeri |
| classification（分類） | Mammalia、 Eulipotyphla、 Soricidae、Sorex 哺乳綱、真無盲腸目、トガリネズミ科、トガリネズミ属 |
| IUCN Status(保全状況) | VULNERABLE |
| Length（体長） | 45-49mm |
| Weight（体重） | 1.5-1.8g |
What is the origin of the name?
When it comes to the Tokyo shrew, it is common to recognize it as a creature of Tokyo. But why? It dates back to 1903. This animal was discovered during this period, but its name comes from the fact that the discoverer, Hawker, mistakenly wrote Yedo (Edo) on the specimen label instead of writing ‘Yezo’ (Ezo). There are also subspecies. The great-footed shrew is the largest species in Japan, and there are also the Ezo shrew and the Japanese shrew.
Scientific name and classification
- 学名：Crocidura dsinezumi
- 目：食虫目（Eulipotyphla）
- 科：セミトガリネズミ科（Soricidae）
- 属：トガリネズミ属（Crocidura）
- 種：トウキョウトガリネズミ (Crocidura dsinezumi)
About habitat
The Tokyo shrew inhabits Hokkaido’s Horonobe Town, Sarufutsu Village, Shiranuka Town, Nemuro City, Shikaoi Town, and Mikasa City.
- Geographic Distribution
This species is endemic to Japan, particularly in the Kanto region.
It is commonly found in the plains and hilly areas of Tokyo, Kanagawa, Saitama, and Chiba prefectures.
It is generally not found in other regions, such as Kyushu and Hokkaido.
- Habitat Characteristics
It has adapted to a variety of environments, including urban suburbs, farmland, grasslands, and woodlands.
It prefers hiding places such as under fallen leaves and grass, or in the crevices of stones and fallen trees.
It is nocturnal, resting in burrows or fallen leaves during the day and active at night to search for food.
- Environmental Conditions
It is not particularly dependent on humidity or proximity to water, and can survive in urbanized environments.
It prefers environments with plenty of soil and fallen leaves, as they have an easy way to find food such as insects.
feature is? What kind of creature is it?
The Tokyo shrew has a pointed nose and small eyes, and although it has the word “mouse” in its name, it is a member of the mole family. The Tokyo shrew is the world’s smallest mammal, with large, mole-like hands that live underground in holes. Therefore, there are times when you cannot see it on the ground. Because of their small size, they have the characteristic of repeatedly feeding and resting every 30 minutes.
- Appearance and Physical Characteristics
Body Type: Small and slender, with a small, rounded head and a pointed snout.
Body Length and Weight:
Body Length: Approximately 5-7 cm
Tail Length: Approximately 3-4 cm
Weight: Approximately 5-10 g
Fur Color: Gray to brownish-gray on the back, light gray on the underside.
Limbs and Tail: Small limbs allow for walking and digging. The slender tail helps with balance.
- Behavior and Ecology
Nocturnal: Rests in burrows or leaf litter during the day, active at night, preying on insects and small invertebrates.
Solitary: Primarily lives alone.
Agility: Small and agile, they excel at hiding under leaves and grass.
- Special Characteristics
Pointed snout, typical of insectivores: Adapted to search for insects and small invertebrates.
High Reproductive Capacity: Has the flexibility to maintain populations in urban environments and agricultural fields.
Adaptability: Able to survive under the influence of human activity, such as in urbanized environments and agricultural land.
What is the ecology like?
The Tokyo shrew is poisonous and is used for hunting. This poison paralyzes enemies and allows it to move quickly to catch insects larger than itself. The main food is insects. The lifespan of the Tokyo shrew is said to be 1 to 2 years. There are still many mysteries regarding ecology. This has not been elucidated by research.
- Diet (What they eat)
They are insectivorous, primarily preying on insects, spiders, earthworms, and small invertebrates.
They hunt by searching under fallen leaves and grass.
They tend to be omnivorous, occasionally eating seeds and fruit.
- Reproduction and Growth
Breeding Season: Active breeding from spring to summer.
Gestation Period: Approximately 3 weeks
Birth: Gives birth to 2-6 pups at a time.
Baby Development: Immediately after birth, they are protected by their mother in a burrow. After a few weeks, their eyes open and they begin preparing to become independent.
- Behavior and Lifestyle
Nocturnal: Rests during the day in burrows or among fallen leaves.
Solitary: They have a territory and only interact with other individuals during the breeding season.
Agility and Stealth: They quickly move under fallen leaves and grass to hunt and avoid danger.
- Movement and Habitat Use
They use burrows, under fallen leaves, and gaps between stones and fallen trees. They can adapt to living in environments affected by human activity, such as urban areas and farmland.
- Natural Enemies/Threats
Natural Enemies: Owls, snakes, cats, etc.
They face relatively few threats from human activity and can survive in urbanized environments, but they are affected by pesticides and environmental destruction.
About Baby Tokyo Shrews
To summarize the appearance, growth, behavior, and mother-child relationship of baby Tokyo shrews (Crocidura dsinezumi), please see below.
- Appearance and Physical Characteristics
Body Color: Immediately after birth, they are pale gray to brown, with a slightly lighter ventral surface. As they grow, they turn the same gray-brown color as adults.
Body Length and Weight:
Body Length: Approximately 3-4 cm
Weight: Approximately 2-4 g
Body Type: Very small, with short, flexible legs and a slender body.
- Growth and Development
Lactation: They are breastfed for approximately three weeks.
Weaning: They begin to eat insects and small invertebrates at three to four weeks of age.
Independence: They leave the burrow at approximately one month of age and learn hunting and hiding techniques from their mother.
Sexual Maturity: They may become capable of breeding at two to three months of age.
- Behavior and Mother-Child Relationships
Cubs live closely with their mothers and are protected in dens.
Mothers teach them how to hunt and avoid danger.
Cubs develop athletic and hunting skills through play with each other.
- Threats and Survival
Cubs are more vulnerable to predators than adults, and are often preyed upon by owls, snakes, and cats.
Insufficient protection from dens and their mothers reduces their chances of survival.
Is the Tokyo shrew an endangered species?
The Tokyo shrew is listed as an endangered species on Japan’s Hokkaido Red List. The Tokyo shrew is listed on the Ministry of the Environment’s Red List. In the first place, they are in a critical situation because their numbers are small.
- IUCN Red List Assessment
Current Assessment: The IUCN (International Union for Conservation of Nature) Red List does not list it as “endangered.”
Due to its relatively wide distribution and ability to adapt to urban and agricultural environments, the decline in wild populations is not considered extreme.
- Status in Japan
The Japanese Ministry of the Environment’s Red List does not specifically list it as endangered.
Although it is affected by urbanization and agricultural development, it lives in urban areas and has adapted reliably.
- Conservation Considerations
Pesticide use and environmental destruction may lead to local population declines.
Competition with invasive rodents may also have an impact.
Is it possible to keep Tokyo shrews?
The ecology of the Tokyo shrew is still a mystery, and it is also poisonous, so we do not recommend raising it easily.
- Ecological Reasons
Nocturnal and highly stealthy: They rest in burrows or fallen leaves during the day, making observation and management difficult.
Small and agile: They have a strong predatory instinct, and cramped captivity can be very stressful.
Specialized Diet: They are insectivorous, feeding on insects and small invertebrates, making it difficult to maintain their health on artificial diets alone.
- Laws and Regulations
While not endangered in Japan, local government and Nature Conservation Act restrictions may apply when capturing and raising wild specimens.
Private captivity is generally prohibited without a capture permit.
- Conditions in Captivity Facilities
Captivity is limited to special-purpose captivity in research institutions and university laboratories.
Captivity requires a nocturnal environment, appropriate insect and invertebrate food, burrows and hiding places, and specialized care.
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