Wednesday 29 May 2013 Greater Cane Rat - Well-trained Swimmers

There are two species of the cane rat and the Greater Cane Rat (Thryonomys Swinderianus) is the larger among the two (surprisingly!). The length of the greater cane rat is about 67-79.2 cm (26.1-30.9 inches). It weighs around 5 - 6.5 kg (11-14.3 lbs). In few cases, these cane rats have been found to weigh as much as 9 kg (19.8 pounds). Males are generally larger, they have massive heads and a powerful and stocky body. They have small but broad fur-covered ears. The most striking feature of greater cane rats is that they have oversized, bright, and orange-colored incisor teeth. The coat has coarse, thick, and pointed hair that varies in color. It is brown on the upper side and the underneath color is much lighter. The color of genitals of a mature cane rat is orange. The hind feet are bigger than the fore feet and they have quite large and well-shaped claws.

The life span of greater cane rats in the wild is short but in captivity, they can survive up to four years of age. These cane rats are considered good swimmers and are found in the marsh areas near streams and rivers. They favor low-lying, marshy areas along riverbanks and streams where dense tall grass and reeds are found.

The greater cane rats are found in almost all the countries to the west of the Sahara Desert but is absent in rain forests and dry scrublands. They occur in Uganda, Kenya, Malawi, Tanzania, Zimbabwe, South Africa, Angola, Namibia, Mozambique, Botswana, Sudan, Gambia, and Cameroon.

The tender new shoots of elephant grass are the primary food of greater cane rats. They also feed on guinea grass, kikuyu, pennisetum grass, plant stems, and roots. They also eat fruits, nuts, and bark of trees in small quantities. They eagerly hunt for vegetables in the fields and are avid consumers of such crops as pumpkin, sweet potato, millet, peanuts, maize, cassava, sorghum, wheat, and cane sugar.

The greater cane rat is a nocturnal and solitary animal. It lives in family groups of adult males, females, and their young ones with the male rat being the dominant member of the group. The gestation period of these cane rats is 152 to 156 days and the female normally gives birth to 2 to 4 pups at a time. Greater cane rats get frightened easily and immediately run towards water to outsmart the predator, since they are excellent swimmers and thus, it is easier for them to escape any danger, once in water.

Like their other smaller counterparts, the greater cane rats are also considered a hazard to the food crops and are viewed as an important food source by humans. Since these animals are found in abundance in almost all places wherever the habitat is suitable for their survival, they are not considered as threatened.

Picture: A male Greater Cane Rat (Thryonomys swinderianus) in a breeding station in Owendo, Gabon, You can help spreading the word about this animal by liking it on facebook

Permanent Link

Thursday 23 May 2013 Mantled Howler - The Noisemaker

The Mantled Howler (Alouatta palliata), also called the Golden-mantled Howling Monkey, is a species of new world monkey in the howler monkey genus Alouatta. Their binomial name is Alouatta palliata, and they are a species that is of least concern on the IUCN redlist, meaning their populations are stable or growing (in the Alouatta palliata palliata subspecies and most common), unlike some of their relatives (the endangered Maranhão Red-handed Howler, and the endangered Guatemalan Black Howler being the two most at risk) however two of the subspecies of the Mantled Howler are endangered, and one of them is critically endangered. They have a black fur that covers their entire body; however they have a golden coloration upon each side which gives them their name. The Mantled Howler is one of the largest monkeys in the New World (specifically Central America and South America) with females reaching close to, or at two feet in length (63 cm), and males being over two feet (~65 cm) - added to that is a prehensile (usable) tail that measures an additional two feet (~64 cm) on average. Adult females can range in weight from seven to seventeen pounds (3-7kg) while adult males will usually come in heavier at ten to twenty two pounds (4.5-10kg). The weight of each monkey can vary depending on nutrition, location, and other factors related to where they are.

Their environment has pushed them to adapt to a mostly folivorous diet, which consists of leaves mostly (between half to three quarters of their daily food intake). The other portion of their diet consists of opportunistic feeding, such as when fruit or flowers are available. If enough fruit is available it can make up half or more of their diet at that given time, however otherwise they stick to leaves. These adaptations include both physical and behavioral. The molars of the Mantled Howler have shearing crests that are higher to help with the consumption of leaves. Their eyesight, unlike other New-world Monkeys, is tri-color (called trichromacy) which means they can see as well as we do, in order to distinguish between young and old leaves. Due to leaves being an extremely low energy food source, the males will make a howl to locate each other, rather than actually look; their distinctive call from the adaptation to a low energy diet: a modified hyoid bone allows for greater amplification of the calls made by males, which expends less energy - being comparable to if you were to talk normally. Some of the behaviors include resting for much of the time, and also being very selective about the leaves they eat, going for young leaves which are less likely to have toxins, and are easier to digest than mature leaves.

There are three known subspecies of the Mantled Howler.

The Ecuadorian Mantled Howler, binomial name Alouatta palliata aequatorialis, is located in Columbia, Panama, Peru, Ecuador, and Costa Rica. They are listed as vulnerable and considered endangered due to habitat loss and poaching.

The Golden-mantled Howler, binomial name Alouatta palliata palliata, is the most common and located in Costa Rica, Honduras, Nicaragua, and Guatemala. They are listed as a least-concern due to their healthy population.

The Mexican Howler, binomial name Alouatta palliata mexicana, is only found in Guatemala and Mexico, they are critically endangered and close to extinction due to massive amounts of habitat loss, it is expected to lose more than 80% of its population within the next 3 generations and possibly be extinct after this. This subspecies is in extreme danger.

The species name is palliata, and there are three subspecies (as shown above). The Mantled Howler belongs to the Genus Alouatta of which all the other howlers belong, and Alouatta belongs to the Family Atelidae which is one of the four in the New World Monkeys. Within Atelidae are the howlers, the spider monkeys, the woolly monkeys, and some extinct relatives. Atelidae belongs to the Parvorder Platyrrhini, which includes all of the New World Monkeys, such as the world’s smallest monkey, the Pygmy Marmoset to the sakis, and the squirrel monkeys. Platyrrhini belongs to the Infraorder Simiiformes of which we are members, and all in this Infraorder are called simians. From here on out it is a journey to all of our mammal relatives, as Simiiformes belongs to Suborder Haplorrhini which includes tarsiers and other relatives. Haplorrhini belongs to the Order Primates which includes our relatives like the lemur. Primates are all Euarchontoglires, which is the Superorder we belong to, and that includes our extinct relatives the Plesiadapiformes, the colugos, the treeshrews, and more distantly (being the Glires) rabbits, hares, pikas, and rodents. Euarchontoglires evolved in the late Cretaceous, before the Dinosaurs went extinct, starting way back some 80-90 million years ago - of course 65 million years ago that changed as the Dinosaurs went extinct. Euarchontoglires belong to the Infraclass Eutheria (placental mammals) which belongs to the Subclass Theria (all but monotremes) and that belongs to the Class Mammalia (All mammals).

They are very athletic when the need arises, and their locomotion is determined by their environment. Aided by their prehensile tail they can navigate the trees they live in and will leap from one limb to another if it must. They are an arboreal, meaning they are a tree-dweller, in addition to being diurnal, active in the day, and they mostly climb, walk, or run with all four hands and feet. They usually don’t do anything if they don’t have to however, as they are an exceptionally lazy and inactive monkey due to their very low energy diet - they are nearly comparable to the sloth, as they spend most of their active period eating and their social time is less than five percent. They do live in groups, and they number around 20 to 40 members, and when a young monkey reaches maturity they are usually evicted.

Interesting facts about the Mantled Howler:

They may use tools, as relatives have been recorded shooing away sloths that decided to walk into their trees, such as sticks.

Picture of the mantled howler © by Leonardo C. Fleck, licensed under GFDL You can help spreading the word about this animal by liking it on facebook

Permanent Link

Wednesday 22 May 2013 Bobak Marmot - The Social Steppe Marmot

The Bobak marmot (Marmota bobak) inhabits the prairies and grassland plains of Central Asia, the Ukraine, and Russia. Also known as the steppe marmot, the animal can thrive in areas that most other species cannot such as at the outer edges of cultivated fields.

The Bobak marmot resembles the North American prairie dog. Its most notable characteristics are its round belly, short, stubby legs, and short tail. The length of a Bobak marmot is approximately 24 inches (60 cm), and the weight is around 11 pounds (5 kg). In general, the males are slightly larger than the females. The coat of this prairie dweller is short and thick with longer, darker hairs that jut out beyond the underfur. These darker hairs are prominent between the eyes and on the top of the head. The tail, underbelly, and throat is also generally darker than the rest of the body. In the fall, adult marmots are soft yellow with a dark brown topcoat. During the summer, the sun lightens the coat even more.

Young Bobak marmots feed on the female’s milk for the first couple months of life, and adult marmots feed on wild prairie grasses. Wheatgrass, knotgrass, chicory, clover, and wild oats are the typical meals of the marmot. Occasionally, marmots will graze on sunflowers, crops, and vegetable gardens. Feeding increases prior to winter hibernation and in early spring.

When it is not in hibernation, the Bobak marmot has a remarkably active social life for nearly half the year. In general, each family may have up to five adults and six young. As many as fifteen families can prosper in one square kilometer. Marmots are most active during dawn and dusk, and they spend up to sixteen hours socializing. Mating occurs in early spring, and nearly sixty percent of the females breed each year. Females also act as guards for the colonies. The guard marmot stands erect while searching for danger. If a predator nears, the guard sounds a warning call to the other marmots.

Bobak marmots are prey to foxes, wild dogs, and eagles. Marmots were once hunted for their thick pelts, however hunting and trapping have been prohibited in many regions. Bobak marmots are considered to be at low risk for endangerment. The marmot can live up to fifteen years in captivity, but its longevity decreases in the wild. You can help spreading the word about this animal by liking it on facebook

Permanent Link