Giant root-rat

Tachyoryctes macrocephalus typically have small eyes and thick russet fur, as well as especially prominent incisors. The eyes are placed near the top of the forehead, and are sometimes called "periscopes" due to their ability to scan for predators. Individuals usually lack a part of the ear called a pinna, the limbs are typically short with claws, and they have short tails. The hair is usually gray at its base, and the head is significantly larger than the rest of the body. Giant root-rats typically eats grasses nearby their burrows and spend the majority of their time underground. Their typical body mass is around one kilogram. In the skeleton, its occipital shield is small and horizontal, the zygomatic plate is very broad and vertical, the mesopterygoid fossa is V-shaped and the back of the glenoid fossa is open. Male root-rats are often larger in size compared to female ones. Reproduction Giant root-rats breed year-round and gestation lasts for 37 to 49 days. Some females are polyestrous (conceiving a second young whilst nursing the first) or breed once every 6 months. Individuals use rainfall and changing temperatures to help determine the appropriate time for breeding. Females in the genus Tachyoryctes are induced ovulators, meaning ovulation usually only occurs during mating and not cyclically. Phylogeny Tachyoryctes macrocephalus is endemic to the grasslands in Ethiopia's Bale Mountains. It is a member of the genus Tachyoryctes, a sister genus to Rhizomys. Fossil records have suggested the species previously lived in South Asia up to northern India. The species likely originated from a split with Tachyoryctes splendens (the African root-rat) around 1.3 million years ago. This cladogram shows the position of Tachyoryctes macrocephalus within the taxonomic family Spalacidae: == Behavior ==

Unlike other mole rats, which mostly forage underground, the giant root-rat primarily forages above ground, obtaining food by digging upwards and feasting upon patches of herbage beside the tunnel entrance. Giant root-rats collect their food without leaving the underground path they built, opting to leave the lower half of their body inside whilst quickly grabbing the vegetation outside. The network of tunnels that are built significantly impact the ecology of the surrounding area. Early humans known as hunter-gatherers (around 47,000 years ago) that lived in the Ethiopian region frequently preyed on the giant root-rat as well. Other predators of this species include Servals (Leptailurus serval), African striped weasels (Poecilogale albinucha), Abyssinian owls (Asio abyssinicus), among others. When being attacked by predators, the giant root-rat will try to escape by running back into the holes it had created in the past, and bite the predator if none are available nearby. == Conservation ==

The IUCN Red List has labelled the giant root-rat as an endangered species. Humans settling in areas the rodent inhabits has impacted how Tachyoryctes macrocephalus tends to burrow. They are only found in a relatively small area of less than in the Bale Mountains at a high altitude. Nearby livestock also has an effect on the availability of food for the giant root-rat. The livestock tends to consume the same vegetation as the rodent, thus hindering the availability of its food. Other factors resulting from the nearby livestock hurt the foods the rodents eat; particularly the feces can result in a condition in the soil called "nutrient overloading". This can lead to an increase in invasive plant species, and the movement of nearby animals can trample the rodent's potential food as well. The deteriorating habitat and limited space that the rodent lives in have resulted in a significant decrease in the population, leading to its endangered status. In 2010 there were determined to be around 2000 to 4,800 animals per square kilometre residing in the Bale Mountain area. == References ==