Transandinomys talamancae facts for kids
Quick facts for kids Transandinomys talamancae |
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| Skull of a male from Gatun, Panama, seen from above | |
| Conservation status | |
| Scientific classification | |
| Genus: |
Transandinomys
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| Species: |
talamancae
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| Distribution of Transandinomys talamancae in southern Central America and northwestern South America | |
| Synonyms | |
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Transandinomys talamancae is a type of rodent (like a mouse or rat) found in Central and South America. It lives in lowland forests from Costa Rica all the way to southwestern Ecuador and northern Venezuela. These forests can be up to 1,500 m (5,000 ft) above sea level.
This animal is a medium-sized rice rat, weighing about 38 to 74 g (1.3 to 2.6 oz). It has soft fur that can be reddish or brownish on its back and white or light yellow underneath. Its tail is dark brown on top and lighter below. It also has long ears and feet, and very long whiskers (called vibrissae). Inside its skull, the front part (rostrum) is long, and the braincase is low. The number of chromosomes in its body can vary from 34 to 54.
Scientists first described this species in 1891. Over the years, it was given many different names, which are now all considered to be the same species. For a while, it was grouped with another widespread species. In 2006, scientists decided it was different enough to be placed in its own genus, Transandinomys. It shares this genus with one other species, Transandinomys bolivaris, which has even longer whiskers. These two species look very similar and live in many of the same areas.
Transandinomys talamancae is active at night and lives on the ground. It eats both plants and insects. Male rats tend to move around more and have larger territories than most females. This species can have babies all year round. After being pregnant for about 28 days, a mother rat gives birth to two to five young. These young rats grow up quickly, becoming ready to have their own babies within two months. Many different parasites can live on this species. Because it is common and found in many places, scientists are not worried about it becoming endangered.
Contents
What is Transandinomys talamancae?
Transandinomys talamancae is a medium-sized, brightly colored rice rat. It looks a lot like its close relative, Transandinomys bolivaris. Both species have unusually long whiskers that can reach past their ears when laid back. However, T. bolivaris has even longer whiskers.
Another similar species is Handleyomys alfaroi, which is found from Mexico to Ecuador. H. alfaroi is smaller and darker. Young T. talamancae can sometimes be mistaken for adult H. alfaroi because their fur colors are similar.
How does it look?
The fur of Transandinomys talamancae is short, thick, and soft. Its color can be reddish or brownish on the back, becoming lighter on the sides and cheeks. Its belly is white or light yellow. The fur of T. bolivaris is usually darker.
Young T. talamancae have thin, gray fur. This fur changes to a dark brown color when they are about 35 to 40 days old. Then, when they are 49 to 56 days old, this fur is replaced by the brighter adult fur. Their ears are dark brown, large, and covered with tiny hairs.
| Country | n | Head and body | Tail | Hindfoot | Ear |
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| Panama | 22 | 124.4 (101–136) | 124.7 (110–143) | 29.2 (27–32) | 21.1 (16–25) |
| Colombia | 13 | 135.2 (120–151) | 125.2 (114–140) | 29.5 (27–32) | 19.0 (18–22) |
| Ecuador | 20 | 124 (118–136) | 128.5 (118–137) | 29.1 (28–31) | – |
| Measurements are in millimeters and in the form "average (minimum–maximum)". | |||||
The tail is about the same length as the head and body. It has few hairs and is dark brown on top, lighter underneath. The hindfeet are long, with the middle three toes longer than the outer two. They are white or pale yellow on top. The toes have silvery hairs that are longer than the claws. The claws are short and sharp.
The total length of the head and body is 105 to 151 mm (4.1 to 5.9 in). The tail length is 105 to 152 mm (4.1 to 6.0 in). The hindfoot is 26 to 32 mm (1.0 to 1.3 in) long, and the ear is 17 to 24 mm (0.67 to 0.94 in) long. The rat's body mass is 38 to 74 g (1.3 to 2.6 oz).
Skull and teeth features
The skull of T. talamancae has a long front part (rostrum) and a low braincase. The cheekbone (zygomatic arch) is strong. The openings in the front part of the palate (incisive foramina) are short. The bony palate itself is long and extends past the molar teeth.
The lower jaw (mandible) is not as strong as in T. bolivaris. The upper incisor teeth point backward. The molar teeth are low-crowned and have cusps (bumps) that are higher than the ridges connecting them. Each upper molar has three roots, and each lower molar has two roots.
What about its chromosomes?
The karyotype (the number and appearance of chromosomes) in T. talamancae can be different depending on where the animal lives. Some rats from Venezuela have 34 chromosomes, while others from Venezuela have 40 to 42 chromosomes. This difference is due to changes in how the chromosomes are arranged.
Rats from Ecuador also show variations. Some have 36 chromosomes, while others from a different area have 54 chromosomes. These differences are quite large and show that there's a lot of genetic variation within this species. Other similar species like T. bolivaris and H. alfaroi have even more chromosomes.
Where does it live?
Transandinomys talamancae lives from northwestern Costa Rica south and east into northern Venezuela and southwestern Ecuador. It prefers forests, including both evergreen (trees keep leaves all year) and deciduous forest (trees lose leaves seasonally). It can live in drier forest areas, which helps it spread further into South America than T. bolivaris.
In Costa Rica, it reaches its northern limit, mainly found in the southeastern part of the country. It lives throughout Panama in low-lying areas. Along the Pacific coast of Colombia and Ecuador, it is found on the flat coastal plains and the nearby foothills of the Andes mountains. The furthest south it has been found is in southwestern Ecuador.
It also lives in northern Colombia and western Venezuela. It is separated from some other similar species by areas of open grassland called the Llanos.
Life and behavior
Transandinomys talamancae is a common species. It lives on the ground and is active during the night. These rats build their nests above ground, but sometimes they use burrows made by other animals. Their diet is omnivorous, meaning they eat both plants (like seeds and fruits) and insects (both adult and larval forms).
Male rats usually travel longer distances than females. In one study, the average home range (the area an animal uses) was about 1.33 hectares (3.3 acres), with males having larger ranges. The number of rats in a population can change throughout the year, often peaking after the rainy season.
Reproduction and life cycle
In Panama, Transandinomys talamancae breeds all year round. In Venezuela, breeding activity is highest in June–July and December. In studies, the gestation period (how long the mother is pregnant) is about 28 days. In the wild, it can be between 20 to 30 days.
Females can have an average of six litters (groups of babies) per year. Each litter usually has two to five young, with an average of about four. This means a single female could potentially have about 24 babies in a year, though most don't live that long. Larger females might have more babies per litter. These young rats grow up fast, becoming ready to breed themselves in less than two months. Most of these rats do not live longer than a year in the wild. The average age at death is about 2.9 months.
Many different small creatures can live on T. talamancae. These include ten types of mites, thirteen types of chiggers, and four types of fleas. Also, two types of sucking lice have been found on this species.
Conservation status
Transandinomys talamancae is a widespread and common species. Because of this, the IUCN Red List lists it as "Least Concern". This means scientists are not worried about it becoming endangered. It lives in many protected areas and can even live well in areas where humans have changed the habitat. There are no major threats known to this species.
