GORILLA

 About Gorilla:

Gorillas are the largest species of primates. Gorillas are ground-dwelling, predominantly herbivorous apes that inhabit the forests of centralAfrica. Gorillas are divided into two species and (still under debate as of 2008) either four or five subspecies. The DNA of gorillas is highly similar to that of a human, between 95 and 99% depending on what is counted, and they are the next closest living relatives to humans after the two chimpanzee species.

Gorillas' natural habitats cover tropical or subtropical forests in Africa. Although their range covers a small percentage of Africa, gorillas cover a wide range of elevations. The Mountain Gorilla inhabits the Albertine Rift montane cloud forests of the Virunga Volcanoes, ranging in altitude from 2,200–4,300 metres (7,200–14,100 ft). Lowland Gorillas live in dense forests and lowland swamps and marshes as low as sea level, with Western Lowland Gorillas living in Central West African countries and Eastern Lowland Gorillas living in the Democratic Republic of the Congonear its border with Rwanda.

Etymology:

The American physician and missionary Thomas Staughton Savage and naturalist Jeffries Wyman first described the Western Gorilla (they called it Troglodytes gorilla) in 1847 from specimens obtained in Liberia. The name was derived from the Greek word "Γόριλλαι" (Gorillai), a "tribe of hairy women" described by Hanno the Navigator, a Carthaginian navigator and possible visitor (circa 480 BC) to the area that later became Sierra Leone.

 Evolution and classification:

The closest relatives of gorillas are chimpanzees and humans, all of the Hominidae having diverged from a common ancestor about 7 million years ago. Human genes differ only 1.6% on average from their corresponding gorilla genes in their sequence, but there is further difference in how many copies each gene has.

Until recently there was considered to be a single gorilla species, with three subspecies: the Western Lowland Gorilla, the Eastern Lowland Gorilla and the Mountain Gorilla. There is now agreement that there are two species with two subspecies each. More recently it has been claimed that a third subspecies exists in one of the species. The separate species and subspecies developed from a single type of gorilla during the Ice Age, when their forest habitats shrank and became isolated from each other.

Primatologists continue to explore the relationships between various gorilla populations. The species and subspecies listed here are the ones upon which most scientists agree.

§  Genus Gorilla 

§  Western Gorilla (Gorilla gorilla)

§  Western Lowland Gorilla (Gorilla gorilla gorilla)

§  Cross River Gorilla (Gorilla gorilla diehli)

§  Eastern Gorilla (Gorilla beringei)

§  Mountain Gorilla (Gorilla beringei beringei)

§  Eastern Lowland Gorilla (Gorilla beringei graueri)

The proposed third subspecies of Gorilla beringei, which has not yet received a trinomen, is the Bwindi population of the Mountain Gorilla, sometimes called the Bwindi Gorilla.

Some variations that distinguish the classifications of gorilla include varying density, size, hair color, length, culture, and facial widths. There are now thought to be over 100,000 Western Lowland Gorillas in the wild, with 4,000 in zoos; Eastern Lowland Gorillas have a population of 4,000 in the wild and 24 in zoos. Mountain Gorillas are the most severely endangered, with an estimated population of about 620 left in the wild and none in zoos.

Physical characteristics: 

Gorillas move around by knuckle-walking, although they sometimes walk bipedally for short distances while carrying food or in defensive situations. Adult males also called as silverbacks range in height 1.65–1.75 metres (5 ft 5 in–5 ft 9 in), and in weight 140–200 kg (310–440 lb). Adult females are often half the size of a silverback, averaging about 1.4 metres (4 ft 7 in) tall and 100 kg (220 lb). Occasionally, a silverback of over 1.8 metres (5 ft 11 in) and 230 kg (510 lb) has been recorded in the wild. Obese gorillas in captivity have reached a weight of 270 kg (600 lb). Gorillas have a facial structure which is described as mandibular prognathism, that is, their mandibleprotrudes farther out than the maxilla.

The Eastern Gorilla is more darkly colored than the Western Gorilla, with the Mountain Gorilla being the darkest of all. The Mountain Gorilla also has the thickest hair. The Western Lowland Gorilla can be brown or grayish with a reddish forehead. In addition, gorillas that live in lowland forests are more slender and agile than the more bulky Mountain Gorilla.

Almost all gorillas share the same blood type (B) and, like humans, have individual finger prints. Their eye color is dark brown, framed by a black ring around the iris. 

Intelligence: 

Gorillas are considered highly intelligent. A few individuals in captivity, such as Koko, have been taught a subset of sign language (see animal language for a discussion). Like the other great apes, gorillas can laugh, grieve, have "rich emotional lives," develop strong family bonds, can make and use tools, and can think about the past and future. Some researchers believe that gorillas have spiritual feelings or religious sentiments. Gorillas have been shown to have cultures in different areas revolving around different methods of food preparation, and gorillas will show individual color preferences.

Tool use: 

The following observations were made by a team led by Thomas Breuer of the Wildlife Conservation Society in September 2005. Gorillas are now known to use tools in the wild. A female gorilla in the Nouabalé-Ndoki National Park in the Republic of Congo was recorded using a stick as if to gauge the depth of water whilst crossing a swamp. A second female was seen using a tree stump as a bridge and also as a support whilst fishing in the swamp. This means that all of the great apes are now known to use tools.

In September 2005, a two and a half year old gorilla in the Republic of Congo was discovered using rocks to smash open palm nuts inside a game sanctuary. While this was the first such observation for a gorilla, over 40 years previously chimpanzees had been seen using tools in the wild, famously 'fishing' for termites. Great apes are endowed with a semi-precision grip, and certainly have been able to use both simple tools and even weapons, by improvising a club from a convenient fallen branch.

FROGS

 About Frogs:

Frogs are amphibians in the order Anura (meaning "tail-less", from Greek an-, without + oura, tail), formerly referred to as Salientia (Latinsalere (salio), "to jump"). Most frogs are characterized by a short body, webbed digits (fingers or toes), protruding eyes and the absence of a tail. Frogs are widely known as exceptional jumpers, and many of the anatomical characteristics of frogs, particularly their long, powerful legs, are adaptations to improve jumping performance. Due to their permeable skin, frogs are often semi-aquatic or inhabit humid areas, but move easily on land. They typically lay their eggs in puddles, ponds or lakes, and their larvae, called tadpoles, have gills and develop inwater. Adult frogs follow a carnivorous diet, mostly of arthropods, annelids and gastropods. Frogs are most noticeable by their call, which can be widely heard during the night or day, mainly in their mating season.

The distribution of frogs ranges from tropic to subarctic regions, but most species are found in tropical rainforests. Consisting of more than 5,000 species described, they are among the most diverse groups of vertebrates. However, populations of certain frog species are decliningsignificantly.

A popular distinction is often made between frogs and toads on the basis of their appearance, but this has no taxonomic basis. (Members of the anuran family Bufonidae are called true toads, but many species from other families are also called toads.) In addition to their ecological importance, frogs have many cultural roles, such as in literature, symbolism and religion, and they are also valued as food and as pets.

 Call:

Some frog calls are so loud, they can be heard up to a mile away. The call of a frog is unique to its species. Frogs call by passing air through the larynx in the throat. In most calling frogs, the sound is amplified by one or more vocal sacs, membranes of skin under the throat or on the corner of the mouth that distend during the amplification of the call. The field of neuroethology studies the neurocircuitry that underlies frog audition.

Some frogs lack vocal sacs, such as those from the genera Heleioporus and Neobatrachus, but these species can still produce a loud call. Their buccal cavity is enlarged and dome-shaped, acting as a resonance chamber that amplifies their call. Species of frog without vocal sacs and that do not have a loud call tend to inhabit areas close to flowing water. The noise of flowing water overpowers any call, so they must communicate by other means.

The main reason for calling is to allow males to attract a mate. Males call either individually or in a group called a chorus. Females of many frog species, for example Polypedates leucomystax, produce calls reciprocal to the males', which act as the catalyst for the enhancement of reproductive activity in a breeding colony. A male frog emits a release call when mounted by another male. Tropical species also have a rain call that they make on the basis of humidity cues prior to a rain shower. Many species also have a territorial call that is used to chase away other males. All of these calls are emitted with the mouth of the frog closed.

A distress call, emitted by some frogs when they are in danger, is produced with the mouth open, resulting in a higher-pitched call. The effectiveness of the call is unknown; however, it is suspected the call intrigues the predator until another animal is attracted, distracting them enough for its escape.

Many species of frog have deep calls, or croaks. The English onomatopoeic spelling is "ribbit". The croak of the American bullfrog (Rana catesbiana) is sometimes spelt "jug o' rum". Other examples are Ancient Greek brekekekex koax koax for probably Rana ridibunda, and the description in Rigveda 7:103.6 gómāyur éko ajámāyur ékaħ = "one has a voice like a cow's, one has a voice like a goat's".

Etymology and terminology:

The name frog derives from Old English frogga, (compare Old Norse frauki, German Frosch, older Dutch spelling kikvorsch), cognate with Sanskrit plava (frog), probably deriving fromProto-Indo-European praw = "to jump".

A distinction is often made between frogs and toads on the basis of their appearance, caused by the convergent adaptation among so-called toads to dry environments; however, this distinction has no taxonomic basis. The only family exclusively given the common name "toad" is Bufonidae, but many species from other families are also called "toads," and the species within the toad genus Atelopus are referred to as "harlequin frogs".

Taxonomy:

The use of the common names "frog" and "toad" has no taxonomic justification. From a taxonomic perspective, all members of the order Anura are frogs, but only members of the family Bufonidae are considered "true toads". The use of the term "frog" in common names usually refers to species that are aquatic or semi-aquatic with smooth and/or moist skins, and the term "toad" generally refers to species that tend to be terrestrial with dry, warty skin. An exception is the fire-bellied toad (Bombina bombina): while its skin is slightly warty, it prefers a watery habitat.

Frogs and toads are broadly classified into three suborders: Archaeobatrachia, which includes four families of primitive frogs; Mesobatrachia, which includes five families of more evolutionary intermediate frogs; and Neobatrachia, by far the largest group, which contains the remaining 24 families of "modern" frogs, including most common species throughout the world. Neobatrachia is further divided into the Hyloidea and Ranoidea. This classification is based on such morphological features as the number of vertebrae, the structure of the pectoral girdle, and the morphology of tadpoles. While this classification is largely accepted, relationships among families of frogs are still debated. Future studies of molecular genetics should soon provide further insights to the evolutionary relationships among anuran families.

Some species of anurans hybridise readily. For instance, the Edible Frog (Rana esculenta) is a hybrid of the Pool Frog (R. lessonae) and the Marsh Frog (R. ridibunda). Bombina bombina and Bombina variegata similarly form hybrids, although these are less fertile, giving rise to a hybrid zone.

PORCUPINES

 About Porcupines:

Porcupines are rodents with a coat of sharp spines, or quills, that defend or camouflages them from predators. They are indigenous to the Americas, southern Asia, and Africa. Porcupines are the third largest of the rodents, behind the capybara and the beaver. Most porcupines are about 25–36 in (63–91 cm) long, with an 8–10 in (20–25 cm) long tail. Weighing between 12–35 lb (5.4–16 kg), they are rounded, large and slow. Porcupines come in various shades of brown, grey, and the unusual white. Porcupines' spiny protection resembles that of the unrelatederinaceomorph hedgehogs and monotreme echidnas.

The common porcupine is an herbivore. It eats leaves, herbs, twigs and green plants like skunk cabbage and clover and in the winter it may eat bark. It often climbs trees to find food. It is mostly nocturnal, but will sometimes forage for food in the day. Porcupines have become a pest inKenya and are eaten as a delicacy.

The name porcupine comes from Middle French porc espin (spined pig). A regional American name for the animal is quill pig.

 Species:

A porcupine is any of 29 species of rodent belonging to the families Erethizontidae (genera: Coendou, Sphiggurus, Erethizon, Echinoprocta, and Chaetomys) or Hystricidae (genera: Atherurus, Hystrix, and Trichys). Porcupines vary in size considerably: Rothschild's Porcupine ofSouth America weighs less than a kilogram (2.2 lb (1.00 kg)); the Crested porcupine found in Italy, Sicily, North Africa and sub-Saharan Africacan grow to well over 10 kg (22 lb). The two families of porcupines are quite different, and, although both belong to the Hystricognathi branch of the vast order Rodentia, they are not closely related.

The eleven Old World porcupines tend to be fairly big, and have spikes that are grouped in clusters.

The two New World porcupines are mostly smaller (although the North American Porcupine reaches about 85 cm/33 in in length and 18 kg/40 lb), have their quills attached singly rather than grouped in clusters, and are excellent climbers, spending much of their time in trees. The New World porcupines evolved their spines independently (through convergent evolution) and are more closely related to several other families of rodent than they are to the Old World porcupines. Porcupines have a relatively high longevity and had held the record for being the longest-living rodent, which was recently broken by the Naked Mole Rat (Heterocephalus glaber).

 Quills:

Porcupines' quills, or spines, take on various forms, depending on the species, but all are modified hairs coated with thick plates of keratin, and they are embedded in the skin musculature. Old World porcupines (Hystricidae) have quills embedded in clusters, whereas in New World porcupines (Erethizontidae), single quills are interspersed with bristles, underfur, and hair.

Quills are released by contact with them, or they may drop out when the porcupine shakes its body, but cannot be projected at attackers. New quills grow to replace lost ones. From ancient times, it was believed that porcupines could throw their quills at an enemy, but this has long been refuted.

Habitat:

Porcupines occupy a short range of habitats in tropical and temperate parts of Asia, Southern Europe, Africa, and North and South America. Porcupines live in forests, deserts, rocky outcrops, hillsides and grasssides. Some New World porcupines live in trees, but Old World porcupines stay on the rocks. Porcupines can be found on rocky areas up to 3,700 m (12,100 ft) high. Porcupines are generally nocturnal but are occasionally active during daylight.

Salt licks:

Porcupines in search of salt sometimes encroach on human habitats, eating plywood cured with sodium nitrate, certain paints, tool handles, doors, tables, houses, footwear, clothes and other items that have been coated in salty sweat. Porcupines are attracted to roads in areas where rock salt is used to melt ice and snow and are known to gnaw on vehicle tires or wiring coated in road salt. Salt licks placed nearby can prevent porcupines from injuring themselves.

Natural sources of salt consumed by porcupines include varieties of salt-rich plants (such as yellow water lily and aquatic liverwort), fresh animal bones, outer tree bark, mud in salt-rich soils, and objects imbued with urine.