San Bernardino kangaroo rat facts for kids
Quick facts for kids Dipodomys merriami parvusSan Bernardino kangaroo rat |
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| Conservation status | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Heteromyidae |
| Genus: | Dipodomys |
| Species: | |
| Subspecies: |
D. m. parvus
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| Trinomial name | |
| Dipodomys merriami parvus Elliot, 1901
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The San Bernardino kangaroo rat (Dipodomys merriami parvus) is a small, jumping rodent. It belongs to the same family as mice and rats, called Heteromyidae. This special rat is one of 19 types of Merriam's kangaroo rat. These different types live in dry areas of the southwestern United States and Mexico.
Like other Merriam's kangaroo rats, the San Bernardino kangaroo rat has four toes on its back feet. Because it has lived separately for a long time, it has become quite unique. It is different from other Merriam's kangaroo rats.
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What Does the San Bernardino Kangaroo Rat Look Like?
The San Bernardino kangaroo rat looks like other kangaroo rat species. It has big back feet for jumping, just like a kangaroo. It also has a long tail that helps it balance when it jumps. This rat has special cheek pouches, like a hamster. It uses these pouches to carry food.
Its body is about 95 millimeters (3.7 inches) long. Its total length, including the tail, is about 230–235 millimeters (9-9.3 inches). Its fur is a light yellow color with a lot of dusty brown mixed in. The stripes on its tail are medium to dark brown. Its tail hairs and foot pads are also dark brown. The sides of its body and its cheeks look dusky.
This specific type of kangaroo rat, D. m. parvus, is darker and smaller. It is different from two other types of Merriam's kangaroo rats. These other types live in Southern California. This rat has changed a lot to fit its home. Some experts even think it is almost a separate species.
Where Does the San Bernardino Kangaroo Rat Live?
For many small rodents, the type of soil is very important. It helps decide where different species can live. The San Bernardino kangaroo rat lives in areas with sandy loam soil. This type of soil is found in places like alluvial fans and flood plains. Alluvial fans are fan-shaped deposits of soil left by rivers. Flood plains are flat areas next to rivers that can flood.
In these areas, the rats can dig small, simple burrows. The plants in these places are usually chaparral and coastal sage scrub. These are types of brushy plants. These special habitats can be new, in-between, or old. New habitats flood often and have fewer plants. Old habitats flood less and have more plants. The San Bernardino kangaroo rat likes the in-between habitats the most.
Where Are They Found?
The San Bernardino kangaroo rat is found in seven separate places. But they are not spread out evenly. The four smallest groups live near City Creek, Etiwanda, Reche Canyon, and South Bloomington.
The largest groups, with the most suitable land, are found near the Santa Ana River, Lytle and Cajon Creek, and the San Jacinto River.
Long ago, this rat lived in a very large area. It covered about 320,000 acres (128,000 hectares). By the 1930s, its home had shrunk to about 28,000 acres (11,200 ha). In 1998, its home was only about 3,247 acres (1,299 ha). This shows a big loss of their living space.
What Threats Do Humans Cause?
The U.S. Fish and Wildlife Service says this rat is in danger. It is threatened by many things humans do. These include destroying its home, making its home worse, and breaking its home into small pieces. This happens because of sand and gravel mining. It also happens because of flood control projects and new buildings in cities.
Sand and gravel mining and city growth directly destroy the rat's home. Flood control projects also cause problems. These projects include dams, levees, and berms. They stop natural flooding. When flooding stops, the rat's favorite in-between habitat changes. It becomes an "old" habitat with too many plants. The rats need open, sandy areas to live.
Areas affected by these human activities include the Santa Ana River, Lytle and Cajon Creek, and the San Jacinto River.
City growth also brings domesticated cats. Cats are known to hunt the San Bernardino kangaroo rat. The more cities grow near natural areas, the more likely cats are to hunt these rats.
Besides being hunted, the small, separate groups of rats face other dangers. When their home shrinks and groups are isolated, more rats can die. This is a known problem for rodents and other animals.
Small, isolated groups are also more likely to disappear completely. This can happen from natural events like floods or drought. It can also happen from human-caused events. Because their groups are small, they might also lose their genetic variability. This means they have less variety in their genes. This can make them weaker and less able to survive. Roads, railroad tracks, and flood control channels make it harder for groups to move between areas.
Losing groups to flooding is becoming more common. This is because city growth pushes the remaining rats into active flood plains. These flood areas are designed in ways that make them hard for rats to live in. They flood too often or too severely. Also, in areas where floods have been stopped, the plants grow too thick. This makes the habitat unsuitable for the San Bernardino kangaroo rat.
Past Government Rules That Didn't Help
In 1998, the Fish and Wildlife Service pointed out problems with government rules. Here are some of the issues they found:
- Government agencies made choices that hurt the rat. This happened even when following laws like the California Environmental Quality Act and National Environmental Policy Act.
- Decisions made under the California Environmental Quality Act could be changed. This happened if social or economic reasons were seen as more important.
- California has a program to protect natural areas. But it was a choice for counties to join. San Bernardino and Riverside counties had not joined this program.
- A law called the Surface Mining Control and Reclamation Act of 1977 says mined land must be fixed. But fixing the land might not help the rat. This is because the land's shape and water flow are changed too much.
- The Bureau of Land Management set aside some areas to protect endangered animals. These areas were along the Santa Ana River. They were for animals like the San Bernardino kangaroo rat. But these areas were also planned for water projects. The protected areas for the rat often did not overlap with where the rat actually lived.
- The Clean Water Act does not focus on saving endangered animals. Projects under this act need a permit from the U.S. Army Corps of Engineers. But this agency sometimes let projects go forward without checking them.
