Friday, September 24, 2010

Arabian Gazelle

 

True Wild Life | Arabian Gazelle | The Arabian gazelle, or mountain gazelle has a wide range throughout the Middle East, but is listed and protected in the Arabian Peninsula, Palestine, and Sinai. This species has a slender build with a proportionally long neck and long hind legs. It has a dark brown coat, white underparts and a black, short, and bushy tail. Both male and female gazelles have horns and their ears are relatively short. Adults weigh up to 51 lbs on average and females are smaller than males. Arabian gazelles are excellent runners and can reach speeds of 80 km per hour. They have excellent vision, hearing, and a good sense of smell to help detect predators and to find food.




The Arabian gazelle prefers mountainous and hilly habitat consisting of light forests, fields, or desert plateaus. Days are usually spent in the hills and at night or in the early morning they come down to forage. They prefer to eat grasses, herbs, and shrubs but can eat other varieties of food, depending on what is available in their habitat. Groups consist of three to eight gazelles, and males are territorial preferring one or more females in the group and their young. Mating occurs mainly in the early winter, but can take place year-round if food is not scarce. The female gives birth to only one calf after a gestation period of 180 days. Males may leave after about six months, but females may remain with their mother for life.


The main threats to the species is habitat loss. Also hunting and collecting, trade, alien invasive species, and hybridizers threaten the Arabian gazelle population. Strict laws are currently in place and have helped to prevent poaching of the species, but habitat loss and exploitation continue to be a threat.

Tuesday, September 14, 2010

Darwin's Frog


True Wild Life | Darwin's Frog | Darwin's frog is named after Charles Darwin who came across it on his famous "Voyage of the Beagle". Darwin's frog is a small species of frog, native to the forest streams of Chile and Argentina. Darwin's frogs can be found inhabiting beech-tree forests and fields, in the cooler regions of South America. Darwin's frogs can also be found living near and in slow streams and swamps throughout Chile and across the border into Argentina.

 

Darwin's frog has a very distinct appearance, having evolved to look a bit like a leaf. This means that when the Darwin's frog feels threatened by approaching predators, it simply remains very still on the forest floor looking like a dead-leaf until the danger has passed. Darwin's frog is a small, yet round species of frog that has a triangular shaped head and pointed snout. Despite having some webbing on their back feet, Darwin's frogs do not have webbed front feet as this helps them when moving around on the forest floor.


Like many other amphibian (and indeed frog) species, the Darwin's frog is a carnivorous animal that uses it's long, sticky tongue to catch it's prey. Darwin's frogs feed on a variety of small invertebrates including insects, worms, snails and spiders. Due to it's small size, and despite it's best attempts at blending in, the Darwin's frog has a number of predators in it's native habitat. Small mammals such as rodents, snakes and birds all commonly prey on the Darwin's frog.


The Darwin's frog is well known for the way in which it takes care of it's young. The female lays her eggs, which are then guarded by the male for about 2 weeks. Once hatched, the male Darwin's frog carries the developing tadpoles in a pouch in his throat until they are tiny froglets and are able to hop away. Today, the Darwin's frog is a species that is considered to be vulnerable from extinction mainly due to habitat loss in the Darwin's frog's native habitat, primarily caused by deforestation.

Tuesday, September 7, 2010

Long-Beaked Echidna


True Wild Life | Long Beaked Echidna | Endemic to New Guinea, long-beaked echidnas are widespread and found in both Papua New Guinea in the west and Papua on the Indonesian side. They are also known from the island of Salawati off New Guinea’s western tip, and may possibly occur on the islands of Supiori and Waigeo, although their presence here has yet to be confirmed.


Recently classified as three separate species, long-beaked echidnas belong to an ancient clade of egg-laying mammals that includes the platypus of Australia. They are easily distinguished from short-beaked echidnas by their long snouts, which account for two-thirds of the length of the head. Despite laws designed to protect these species, they are in decline in areas accessible to humans. Echidnas have lost much of their forest habitat to logging, mining and farming, and are regarded as highly prized game animals by local people, who hunt them with specially trained dogs. One species, Attenborough's long-beaked echidna, is thought to have an extremely restricted range and may be at high risk of extinction.


Long-beaked echidnas are monotremes, a group that also includes the short-beaked echidna and duck-billed platypus. Fossil evidence indicates that this group of mammals has changed very little during the last 100 million years. However, the fossils do not provide any evidence of the origins of the group and their ancestral relationships, nor to how they relate to marsupials and placental mammals. Fossil monotremes from the Pleistocene Epoch (which began 1.8 million years ago) are very similar to the living species.


The most distinguishing feature of long-beaked echidnas is their long snouts, which curve downwards and account for two-thirds of the length of the head. They have no teeth; instead their tongues are covered in spikes (teeth-like projections), which are very effective in hooking prey and drawing it into the mouth. They have compact, muscular bodies, with strong limbs and claws for digging. Their back and sides are covered with spines, which vary in colour from white through to dark grey or black. The body is also covered in brownish-black hairs, which sometimes hide the spines. Males are larger than females and have spurs on the inside of the hind limbs, near the foot.


Little is known of the ecology of long-beaked echidnas. They are thought to be largely nocturnal, spending the day resting in shallow burrows or hollow logs, and foraging amongst the forest litter at night for food. The diet consists almost exclusively of earthworms, although individuals may occasionally eat termites, insect larvae and ants. Echidnas lead solitary lives, coming together only to breed. This is thought to be seasonal, with the female laying 4-6 eggs into her pouch each July. Hatching occurs ten days later, and the young echidnas remain in the pouch for a further 6-7 weeks, or until the spines develop. All echidnas have the ability to erect their spines when they feel threatened. If the ground is soft, the animal will burrow into it to protect its belly. On hard ground it will curl up into a spiky ball like a hedgehog.

Leafy Sea Dragon


True Wild Life | Leafy Sea Dragon | Sea Dragons are arguably the most spectacular and mysterious of all ocean fish. Though close relatives of sea horses, sea dragons have larger bodies and leaf-like appendages which enable them to hide among floating seaweed or kelp beds. Sea dragons feed on larval fishes and amphipods, such as and small shrimp-like crustaceans called mysids ("sea lice"), sucking up their prey in their small mouths. Many of these amphipods feed on the red algae that thrives in the shade of the kelp forests where the sea dragons live.



As with their smaller common seahorse (and pipefish) cousins, the male sea dragon carries and incubates the eggs until they hatch. During mating the female deposits up to 250 eggs onto the "brood patch" on the underside of the male's tail. After about eight weeks, the brood hatches, but in nature only about 5 per cent of sea dragons survive to maturity (two years). A fully grown Leafy Sea Dragon grows to about 18 inches (45 cm).


Leafy Sea Dragons are very interesting to watch-- the leafy appendages are not used for movement. The body of a sea dragon scarcely appears to move at all. Steering and turning is through movement of tiny, translucent fins along the sides of the head (pectoral fins, visible above) and propulsion derives from the dorsal fins (along the spine). Their movement is as though an invisible hand were helping, causing them to glide and tumble in peculiar but graceful patterns in slow-motion. This movement appears to mimic the swaying movements of the seaweed and kelp. Only close observation reveals movement of an eye or tiny fins.


Most sources of information about sea dragons say they are found in the ocean waters of southern Western Australia, South Australia and further east along the coastline of Victoria province, Australia.  Sea dragons are protected under Australian law, and their export is strictly regulated. A 1996 assessment by the Australian government's Department of Environmental Heritage indicates "It [the Leafy Sea Dragon] is now completely protected in South Australia because demand for aquarium specimens threatened the species with extinction." Currently the specific law which protects them is called the Environment Protection and Biodiversity Conservation Act 1999.  For a February 2002 updated overview of the leafy sea dragon, see this page from the Department of Environmental Heritage site.

Blanket Octopus


True Wild Life | Blanket Octopus | This is one weird open ocean octopus! It looks like the Batman symbol flying through the ocean. It's common name, Blanket octopus, comes from their large web which they use to glide through the ocean. Blanket octopuses are rarely observed, but when people see them they notice. One, complete with eggs, washed up in Bermuda while I was off island on vacation. It made the local news and was the talk of the island. Another was recently (Sept 2009) spotted in St. Thomas, USVI.


The blanket octopus (Tremoctopus violaceus) is a rarely encountered pelagic species that spends its entire life cycle in the open ocean (Norman et al. 2002). Until the first observation of a living male off the northern Great Barrier Reef, Australia (Norman et al. 2002), males were known only from dead individuals picked up in trawls and plankton nets. Like other pelagic octopus species, T. violaceus exhibits sexual size dimorphism. The degree of sexual size dimorphism in this species, however,  is extraordinary: Females may reach 2 m in length whereas the reproductively mature male collected by Norman et al. was just 2.4 cm long. Individual weights of males and females differ by a factor of at least 10,000 (Norman et al. 2002).


Tremoctopus violaceus lives in the open ocean often in deep water (120-750 m) in the Mediterranean and the North and South Atlantic Ocean. The offspring are likely planktonic given the small size of the eggs. These octopuses may reproduce more than once but no one really knows much about their life history.


Olm


True Wild Life | Olm | The olm (also known as the proteus or the cave salamander) is a blind amphibian exclusively found in the underwater caves of southern European lakes and rivers. The olm is also known as the human fish, which refers to the colour of it's skin. The olm is the only species in it's genus and is found inhabiting the waters that flow underground through an extensive limestone region including waters of the Isonzo river basin near Trieste in Italy, through to southern Slovenia, south-western Croatia, and Herzegovina. The olm is most well known for living it's entire life in the darkness of the underwater caves, which has led this species to adapt quite strangely to life without light. The most notable feature of the olm is the fact that it is blind as it's eyes are not properly developed and instead it must rely on incredible hearing and smell to understand it's surroundings.


In a similar way to the axolotl, the olm does not undergo the drastic transformation from young to adult in the same way that frogs and toads do. The olm is also entirely aquatic, hunting, mating, eating and sleeping in the darkness of the underwater caves. As with other amphibious animals, the olm is a carnivore meaning that it gets all the nutrition it needs from eating other animals. Small invertebrates are the main source of food for the olm including worms, aquatic insects, larvae and snails. Due to the fact that the olm lives out it's life in the safety of a dark, underwater cave, it has fewer predators than it would have living both in the water and on land. Fish and other amphibians are the primary predators of the olm along with the very occasional rodent or bird.


The olm does not reach sexual maturity until it is between 10 and 15 years old, and after mating, female olms lay from 5 to 30 eggs in between rocks in the water where she can protect them from hungry predators. Olm tadpoles are less than an inch long when they hatch and take on the appearance of the adult olm by the time they are a few months old.

Today, due to rising levels of water pollution, olm populations are declining meaning that the olm is now considered to be vulnerable to extinction in their native environment.


Monday, September 6, 2010

7 Extinct Animals

True Wild Life | 7 Extinct Animals | From panthers and pandas to rhinos and tigers, dwindling animal numbers speak of the need to step up conservation efforts – if it’s not already too late. As a kind of wake-up call, we decided to take a look at seven extinct megafauna species captured on camera. With modern photography having only been invented in the 1820s, these snapshots are visible testament to just how recently the creatures shown were wiped out – and a jarring reminder of the precarious situation for many species still left on the planet.

1. The Tarpan

The last Tarpan died on a Ukrainian game preserve at Askania Nova in 1876. A prehistoric type of wild horse that once roamed from Southern France and Spain eastwards to central Russia, the Tarpan died out in the wild in the late 1800s. Reasons for its extinction include the destruction of its forest and steppe habitat to make room for people; hunting by farmers averse to their crops being eaten and mares stolen; and absorption into a growing domestic horse population. There have been various attempts to recreate the Tarpan through re-breeding, resulting in horses that do at least resemble their extinct forebears.

2. The Quagga


Another extinct equine beast – this time a subspecies of zebra – the last wild Quagga was probably shot in the late 1870s, while the last specimen in captivity died in 1883 at Artis Magistra Zoo in Amsterdam. Once abundant in southern Africa, the Quagga fell victim to ruthless hunting for its meat and hide, and because it was seen by settlers as a competitor to livestock like sheep. It was the coat of the Quagga that distinguished it best, with only the front part of its body showing the zebra’s vivid striped markings. As with the Tarpan, projects to breed back the Quagga have produced favourable results, visually at least.

3. The Javan Tiger


The Javan Tiger was a subspecies of tiger found only on the Indonesian island of Java, until it died out as recently as the 1980s. In the early 19th century, the Javan Tiger was common all over the island, but rapid human population increase led to the destruction of its forest habitat. The Javan Tiger was also mercilessly hunted, so that by the 1950s it is thought fewer than 25 remained in the wild. Following in the tracks of the Bali Tiger, which was wiped out in the 1930s, the fate of the Javan Tiger speaks for the precarious position of the tiger species as a whole. Sightings of the subspecies persist but hopes for its survival are fading.

 4. The Caspian Tiger


Another tiger to vanish in the last century was the Caspian Tiger, the last confirmed reports of which date back to before the 1950s. Recent research suggests the Caspian Tiger was largely identical to the Siberian Tiger, but even if not a distinct subspecies, it yet had its own range and habitat. Found in the sparse forest and river basin corridors of Central and Western Asian, this big cat succumbed to intense hunting by the Russian army, who were told to exterminate it during a huge land reclamation programme in the early 1900s. Farmers followed, clearing forestland, and the loss of the Caspian Tiger's primary prey, the boar, spelled its demise.

5. The Syrian Wild Ass


The last member of this species died at Schönbrunn Zoo, Vienna in 1928. Formerly occupying the mountains, deserts and steppes between Palestine and Iraq, the Syrian Wild Ass disappeared from the Syrian desert during the 18th century, not helped by war between Palestine and Syria. It was eradicated in Northern Arabia during the 19th century, and then became most seriously threatened with World War I, when its remaining habitat was overrun with fighting forces. The rest is history. This smallest of all recent members of the horse family stood just over 3 feet high at the shoulder and was generally light in colour.

6. The Bubal Hartebeest



 The Bubal Hartebeest was a species of antelope that became extinct in 1923, when a captive female died in Jardin des Plantes in Paris. It was once found over much of North Africa, at least as far east as Egypt, where it was a mythological and sacrificial beast. However, by the 1900s its range was limited to Algeria and the Moroccan High Atlas mountains. Hunting throughout the 19th century drastically reduced the Bubal Hartebeest’s numbers, sealing its fate. A fawn-coloured animal that stood almost 4 feet at the shoulder, the Bubal Hartebeest was characterised by lyre-shaped horns that almost touched at the base. A beautiful beast, sadly missed.

7. The Thylacine


It was 1936 when the last Thylacine took its final breath in Hobart Zoo, Tasmania. Or so we think. Extremely rare if not extinct on the Australian mainland by the time of European colonisation, the Thylacine survived on the island of Tasmania alongside close cousins like the Tasmanian Devil. There, this distinctive, large-jawed beast found itself with a price on its head, as settlers blamed it for attacks on their sheep. The Thylacine was hunted to extinction by bounty hunters and farmers, though other factors such as disease, the introduction of wild dogs, and human encroachment into its habitat may have also played a part in the tragedy.

Although commonly known as the Tasmanian Tiger or Tasmanian Wolf, the Thylacine was neither feline nor canine: while striped like a tiger and sharing various features with large dogs, this marsupial carnivore was wholly unrelated – and with the pouch to prove it. A favourite in cryptozoological circles, there have been numerous sightings of the Thylacine since 1936 – which continue to this day – though none have yet been confirmed. It will be a rare coup for Mother Nature if another Thylacine is ever discovered; otherwise its most vivid memory will sadly survive in little more than photographic form – another dead hero of the natural world.

Friday, September 3, 2010

Ubuntu 10.10 Wallpapers - Maverick Meerkat

 The wallpapers included in the latest Ubuntu edition the Maverick Meerkat.
Resolution varies from 1600x1050 to 2000x1333.
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