An Animal A Day

last SG · 2005-03-09T00:11:15+00:00

Deepwater Arrowtooth Eel The Deepwater Arrowtooth Eel (Histiobranchus bathybius) is a cutthroat eel of the genus Histiobranchus, found around the world at d...

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Alpine Swift

The Alpine Swift (Apus melba) is a small bird, superficially similar to a large Barn Swallow or House Martin. It is, however, completely unrelated to those passerine species, since swifts are in the order Apodiformes. The resemblances between the groups are due to convergent evolution reflecting similar life styles.

Alpine Swift, Apus melba

These birds have very short legs which they use only for clinging to vertical surfaces. The scientific name comes from the Greek apous, meaning "without feet". They never settle voluntarily on the ground.

Alpine Swifts breed in mountains from southern Europe to the Himalaya. Like Common Swifts, they are strongly migratory, and winter much further south in southern Africa. They wander widely on migration, and are regularly seen in much of Europe and Asia.

Alpine Swifts build their nests in colonies in a suitable cliff hole or cave, laying 2-3 eggs. A swift will return to the same site year after year, rebuilding its nest when necessary. These birds pair for life.

Young swifts in the nest can drop their body temperature and become torpid if bad weather prevents their parents from catching insects nearby.

Alpine Swifts spend most of their lives in the air, living on the insects they catch in their beaks. They drink on the wing, but roost on vertical cliffs or walls.

Alpine Swifts are readily identified by their large size. Their wingspan is 55 cm compared to the 42 cm of Common Swift. They are black except for a white belly and throat, with a dark neck band separating the white areas. They have a short forked tail and very long swept-back wings that resemble a crescent or a boomerang. The flight is slower and more powerful than that of their smaller relative.

The call is a drawn-out twittering.

Taxonomy

This species, and the related African species Mottled Swift, are sometimes separated into the genus Tachymarptis, but genetic evidence suggests that this would leave the remainder of Apus polyphyletic.

In the Sibley-Ahlquist taxonomy, the old order Apodiformes is split. Swifts remain in that order, but hummingbirds are put into a new order, Trochiliformes.

Issue #183

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Alligator Snapping Turtle

The Alligator Snapping Turtle (Macroclemys temminckii) is a larger yet less aggressive relative of the common snapping turtle. It is characterized by a large, heavy head and a thick tail with a dorsal ridge of large scales which gives it a primitive appearance reminiscent of some of the plated dinosaurs. The inside of the turtle's mouth is camouflaged and it possesses a vermiform appendage on the tip of its tongue with which it lures fish.

Alligator Snapping Turtle, Macroclemys temminckii

Like the common snapping turtle, the alligator snapping turtle lives in a largely aquatic environment. Its natural diet consists primarily of small fish and amphibians.

Although some people have raised alligator snapping turtles as pets, keeping them in a bathtub or children's wading pool, this practice cannot be recommended. The alligator snapping turtle's aggressive temperament makes handling it dangerous, particularly to children, household pets, and to those with little caution. A small specimen can be picked up from the rear half of the shell, while a larger specimen should only be picked up by the tail at arms length (a very experienced person may lift by the rear edge of the shell). Caution, however, is required as all four legs have sharp claws and larger turtles can reach their head to the front half of the shell. Furthermore, removing alligator snapping turtles from the wild damages the ecosystems from which they are taken, and is illegal in many jurisdictions.

Conservation status: Vulnerable

Issue #184

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Gulf Fritillary

The Gulf Fritillary, Agraulis vanillae, a striking, bright orange butterfly of the family Nymphalidae. It was formerly classified in a separate family, the Heliconiidae or longwing butterflies, and like other longwings it does have long, rather narrow wings in comparison with other butterflies. It is not closely related to the true fritillaries. It is a medium to large butterfly, with a wingspan of from 6 to 9.5 cm. Its underwings are buff, with large silvery spots. It takes its name from the fact that migrating flights of the butterflies are sometimes seen over the Gulf of Mexico.

Gulf Fritillary, Agraulis vanillae

The Gulf Fritillary is commonly seen in parks and gardens, as well as in open country. Its range extends from Argentina through Central America Mexico, and the West Indies to the southern United States, as far north as the San Francisco Bay Area on the west coast. It is occasionally found further north in the US.

Larva

The larva or caterpillar of the gulf fritillary grows to approximately 4 cm in length and is bright orange in color and covered in rows of black spines on its head and back. The spines are soft to the touch and do not sting. However, the larva are poisonous if eaten, as the bright coloration advertises. The larva feed exclusively on various species of passionflower such as maypop and running pop.

Their toxic flesh provides gulf fritillary caterpillars with excellent protection from predators. Birds avoid them. Some specialized insects have been observed feeding on them, however, and larger caterpillars sometimes eat smaller ones.

The chrysalis is approximately 3 cm long; it is mottled brown and looks like a dry leaf.

Chrysalis of Gulf Fritillary

Cultivation of the passionflower in gardens has enabled the gulf fritillary to extend its range, for example into new areas of southern California.

Conservation status: Secure

Issue #185

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Ayu

The Ayu (Plecoglossus altivelis) is a amphidromous fish, the only species in its genus, Plecoglossus Temminck & Schlegel, 1846, and in family Plecoglossidae (order Osmeriformes). Native to the Palearctic ecozone, it occurs in rivers, lakes, and coastal waters of northern Hokkaido in Japan, the Korean Peninsula, China, and Taiwan.

Ayu, Plecoglossus altivelis, on a Japanese postage stamp. The ayu has great cultural significance in Japan.

Omnivorous, the ayu feeds on algae, crustaceans, insects, sponges, and worms. The adults ascend from coastal waters into the lower reaches of rivers to spawn in the spring. The larvae descend to the sea immediately on hatching and winter there before returning to fresh water again in the spring. Most but not all individuals die after their first spawning.

The flesh of the ayu has a distinctive, sweet flavour with "melon and cucumber aromas" (Gadsby). It is consequently highly prized as a food fish. Japanese anglers catch it with live lures as well as by a traditional method whereby captive cormorants catch the ayu and regurgitate the fish for human consumption (Akimichi). It is also fished commercially in large numbers, and captive juveniles are raised in aquaculture before being released into rivers for sport fishing.

P. altivelis is also known as the sweetfish (for the sweetness of its flesh) or, in reference to its typical one-year life span, nen-gyo (year-fish).

Subspecies

The Ryukyu ayu-fish (P. altivelis ryukyuensis), is a subspecies of ayu, endemic to the Ryukyu Islands, which reaches a maximum total length of only about 14 cm (5.5 in). IUCN classifies the Ryukyu ayu-fish as Endangered on the basis of declining and highly fluctuating population and limited and declining range and habitat.

Conservation status: Secure

Issue #186

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Four Spot Orb Weaver

The Four Spot Orb Weaver (Araneus quadratus) is a common orb weaver spider found in Europe and Asia. Females can reach 17 mm in length, especially when gravid, males approximately half that. They are quite variable in appearance, ranging from brown to bright orange or green, but they always have the characteristic four white spots on the abdomen. The darker color morphs are easiest to identify, due to the contrast between the white spots and the rest of the body. The legs are sometimes brightly striped.

Four Spot Orb Weaver, Araneus quadratus

The spider lives in gardens, wooded areas, or wherever there is vegetation to string an orb web across. This species builds its web close to the ground to catch jumping insects such as small grasshoppers. The female builds the more elaborate web, complete with a funnel-shaped retreat off to the side where she goes during inclement weather. The web is smaller and closer to the ground than those of other species of orb weaver.

Issue #187

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Mastodon

Mastodons are members of an extinct genus of the order Proboscidea, and were herbivores who resembled modern elephants. The American mastodon (Mammut americanum) lived in North America beginning almost four million years ago, becoming extinct approximately 10,000 years ago. They were furry, and had a height of about three meters. They differed from mammoths mainly in the blunt cone shape of their teeth, which were more suited to chewing leaves rather than for grazing. The name mastodon (or mastodont) means mastoid teeth (Greek "nipple tooth"), and is also an obsolete name for their genus.

A Mastodon, order Proboscidea, skeleton in museum in Bismarck, North Dakota.

Their tusks sometimes exceeded five meters in length. Their meat was a food source for early humans, and archeologists are still trying to determine what role, if any, the early human settlers of North America played in the extinction of the mastodon.

Conservation status: Prehistoric

Issue #188

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Xoloitzcuintli

A Xoloitzcuintli or Xoloitzcuintle (the initial x is pronounced as an sh), also known as Tepeizeuintli or Mexican Hairless, is a rare, almost hairless breed of dog which can be quite variable in size, ranging from under 10 pounds (4 kg) to about 50 pounds (20 kg), with an average body temperature of 40°C. The breed was native to Pre-Columbian Mesoamerica, and may date back 3,500 years. Owners of this dog call them "xolos" for short.

Xoloitzcuintli

The Aztec and Maya cultures are believed to have kept this animal as pets. They also ate the meat of the Xoloitzcuintli.

Depending on which genes an individual dog gets, many members of this breed are also missing several teeth.

There is also a "coated" xolo with a very short coat of hair. They appear randomly in the same litters as hairless ones.

Alternative names: Xoloitzcuintli, Xoloitzcuintle, Xoloitzquintle, Tepeizeuintli
Common nicknames: Xolo
Country of origin: Mexico

Issue #189

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Black Rat

The Black Rat (Rattus rattus, also known as the Asian Black Rat, Ship Rat, Roof Rat or House Rat) is a common long-tailed rodent of the genus Rattus (Old World rodents) and the subfamily murinae (Murine rodents). The species originated in tropical Asia and spread through the Near East in Roman times before reaching Europe in the 8th Century and spreading with Europeans across the world. Today it is again largely confined to warmer areas, having been supplanted by the brown rat (Rattus norvegicus) in cooler regions.

Black Rat, Rattus rattus

Despite its name it comes in several colour forms. Compared to the Brown Rat, it is a poorer swimmer, but more agile and a better climber, tending even to flee upwards. It is usually black to light brown in colour with a lighter underside. A typical rat will be 20 cm long with a further 20 cm of tail. It is nocturnal and omnivorous, with a preference for grains. In a suitable environment it will breed throughout the year, with a female producing three to six litters of up to twenty young. Females may regulate their production of offspring during times when food is scarce, throwing as few as only one litter a year. Rattus lives for about 2-3 years. Social groups of up to sixty can be formed.

Rattus has been known to fall victim of a number of diseases, of which bubonic plague, typhus, and trichinosis are the most well known.

Issue #190

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African Collared Dove

The African Collared Dove (Streptopelia roseogrisea) is a small dove found in Africa in the arid region south of the Sahara. Its range extends in a band right across the continent, and into southern Arabia. Although it lives in arid lands, it is found around water sources.

African Collared Dove, Streptopelia roseogrisea

This bird is typically around 26 cm in length. Its upper body, from shoulders to tail, is a pale grayish brown, though the wing edge has a bluish tinge. Flight feathers are darker, and nearly black. Head, neck and breast are pinkish shading to white on the chin and belly. There is little sexual dimorphism.

The African Collared Dove is the species thought to be the wild ancestor of the domestic Barbary Dove, though some suggest the Eurasian Collared Dove (Streptopelia decaocto) may also have been involved. The African Collared Dove is able to hybridise with the Barbary Dove, and it is thought that the increase in the range of colours of Barbary Doves available that occurred in the later twentieth century was the result of the importation of African Collared Doves into the United States for interbreeding.

It is reported to have been introduced into New Zealand, but it is more likely that the birds there are descended from domestic Barbary Doves.

Issue #191

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Collared Lizard

The Collared Lizard, Crotaphytus collaris, is a North American lizard that can be up to a foot (30 cm) long, with a large head and powerful jaws. They are well known for the ability to run on their hind legs, looking like small dinosaurs. The collared lizard is the "state reptile" of the United States state of Oklahoma, where it is known as the mountain boomer. The name "collared lizard" comes from the lizards' distinct coloration, which includes bands of black around the neck and shoulders that look like a collar.

Collared Lizard, Crotaphytus collaris

These reptiles are often tamed and kept as pets. When born in captivity, they are quite docile and tolerant of interaction with humans. They are very active lizards, requiring a large amount of space to run. They prefer high temperatures, typically 105-110°F (40-43°C) at their basking spot and 80°F (26°C) elsewhere in their habitat during the day. Some collared lizards eat small amounts of fruit or vegetables, but most prefer a diet of insects. Like many reptiles, in captivity they must be provided a diet supplemented with extra calcium and a light source with ample UVB radiation to reduce the risk of bone disorders.

The origin of the name "mountain boomer" is unclear, but is thought to have originated among settlers travelling west during the Gold Rush. One theory is that settlers mistook the sound of wind in canyons for the call of an animal in an area where the collared lizard was abundant. In reality, collared lizards are silent.

Issue #192

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Devil's coach horse beetle

The Devil's coach-horse beetle (Staphylinus olens) is a very common and widespread European beetle, belonging to the large family of the Rove beetles (Staphylinidae). It is also called Ocypus olens by some authors. The species has been introduced to the United States, New Zealand and Australia.

Devil's coach-horse beetle, Staphylinus olens

This black beetle usually shelters during the day under stones, logs or leaf litter. It is most often seen in forests, parks and gardens between April and October. It is a long-bodied beetle. At about 25-28 mm it is even one of the larger British beetles. Its wing covers (elytra) are short covering only its thorax, exposing the abdominal segments. The abdominal musculature is powerful and the abdominal segments are covered with sclerotized plates. It is capable of flight but its wings are rarely used. It is clothed with fine black hairs.

It is well known for its habit of raising its long and uncovered abdomen and opening its jaws, rather like a scorpion when threatened. This explains one of its alternative names, the cock-tail beetle. Although it has no 'sting in its tail' it can give a painful bite with its strong pincer-like jaws. It also emits a foul smelling odour, as a defensive secretion, from a pair of white glands at the end of its abdomen. In the scientific name olens means oily and describes this secretion.

It is a predator, hunting mainly by night, feeding on invertebrates including worms and woodlice, as well as carrion. The prey is caught in the mandibles which are also used to cut and together with the front legs to manipulate the food into a bolus. The bolus is repeatedly chewed and swallowed, emerging covered with a brown secretion from the foregut, until it is reduced to a liquid which is digested. Skin (in the case of earth worms) and hard materials (from arthropods) are left. The larvae are also carnivorous with similar eating habits.

Females lay their eggs from 2-3 weeks after first mating. They are large (4mm) and white with a darker band and laid singly in damp conditions under moss, stones, cow pats or leaf litter, typically in the Autumn. After around 30 days the eggs split and the larvae emerge, white with a straw coloured head. The larva lives largely underground, and feeds on similar prey to the adult and has the same well developed mandibles. It adopts the same display with open jaws and raised tail when threatened. The larva goes through three stages of growth (instars) the final stage ranging from 20 to 26 mm in length. At around 150 days the larva pupates for about 35 days and emerges as an adult with its final colouring, fully formed except for the wings which cannot be folded neatly beneath the elytra for several hours. Adults can survive a second winter, some by hibernating in burrows and not emerging until March while others remain active.

This beetle has been associated with the Devil since the Middle Ages, hence its common name. Other names include Devil's footman or Devil's steed. In Ireland the beetle is known as darbhadal (literally Devil's beast) and it is said that the Devil assumes the form of this beetle to eat sinners. As with many supposed bringers of ill-luck superstition holds that people can turn the creature's powers to their own advantage and it is said that reapers used to enclose the body of a Devil's coach horse beetle in the handle of their scythes to improve their skill. The origin's of these beliefs can perhaps be explained by the beetle's threatening appearance, and its habit of eating carrion.

Issue #193

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Milkfish

The Milkfish (Chanos chanos) is an important food fish in Southeast Asia. It is the sole living species in the family Chanidae (about seven extinct species in five additional genera have been reported).

Milkfish, Chanos chanos

Milkfish have a generally symmetrical and streamlined appearance, with a sizable forked caudal fin. They can grow to 1.7 m, but are most often about 1 meter in length. They have no teeth, and generally feed on algae and invertebrates.

They occur in the Indian Ocean and across the Pacific Ocean, tending to school around coasts and islands with reefs. The youngest larvae live at sea for 23 weeks, then migrate to mangrove swamps, estuaries, and sometimes lakes, returning to sea to mature sexually and reproduce.

The larvae are collected from rivers and raised in ponds, where they can be fed almost anything and grow very quickly, then are sold either fresh, frozen, canned, or smoked.

Issue #194

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Peppery furrow shell

The Peppery furrow shell, Scrobicularia plana, is the only species currently recognized by ITIS in the genus Scrobicularia; however some sources recognise other species such as Scrobicularia cottardi. It is a bivalve mollusc commonly found on sandy or muddy sea coasts and estuaries in northern Europe, the Mediterranean and West Africa. They may be found at quite high densities.

Peppery furrow shell, Scrobicularia plana

The shell can be anything from white through yellowish to a pale brownish-grey in colour, up to 65 cm in diameter. Its interior is nacreous and white or yellowish in colour. The shell is thin but quite deep, and circular growth ridges can be seen, closely packed together. It is a filter feeder, with long siphons, burying itself up to 20 cm deep in sand or mud. When buried, it leaves star-shaped markings on the surface, and specimens can be found by looking for these. If the siphons are browsed by fish or other predators, they regenerate in a few days.

The genus Scrobicularia is sometimes placed as the sole genus in a family, Scrobicularidae. It is now often placed instead in the related family Semelidae, as shown in the box on the right. However this placement may change as molecular systematics provides new insights into the cladistics of the bivalves.

The peppery furrow shell is not regarded as edible.

Issue #195

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Megalodon

The Megalodon or Megatooth shark (Carcharodon megalodon, from ancient Greek, mega + odon, lit. "big tooth") was a giant shark that lived between 5 million and 15,000 years ago, recent enough to have seen our ancestors.

The Megalodon is known only from fossil teeth, which are in many ways similar to great white shark teeth; recent studies cited by Roesch suggest Megalodon was a "close relative" of the great white. Some estimates of this creature's size range up to 75-80 feet (about 24 metres). Previous much larger reconstructions of the shark's size, up to about 150 feet (40 m), are generally considered inaccurate.

Tooth of a Megalodon, Carcharodon megalodon, with a quarter for scale.

Some recent reports of large shark-like creatures have been interpreted as surviving Megalodons, but such reports are generally considered misidentification of whale sharks or other large creatures, although some cases are possible, but unlikely sightings of abnormally large great whites.

Megalodon teeth have been discovered that some argue date as recently as 10,000 to 15,000 years ago, perhaps making the species' extinction a recent event, and making it more conceivable that Megalodon might yet survive in the deep ocean, living on the heat from hydrothermal vents. In addition, bones and carcasses of very large sperm whales have been found with megalodon teeth jammed into them. One famed example is this, told by an unknown writer:

"In the year 1918 I recorded the sensation that had been caused among the "outside" crayfish men at Port Stephens, when, for several days, they refused to go to sea to their regular fishing grounds in the vicinity of Broughton Island. The men had been at work on the fishing groundswhich lie in deep waterwhen an immense shark of almost unbelievable proportions put in an appearance, lifting pot after pot containing many crayfishes, and taking, as the men said, "pots, mooring lines and all". These crayfish pots, it should be mentioned, were about 3 feet 6 inches [1.06 m] in diameter and frequently contained from two to three dozen good-sized crayfish each weighing several pounds. The men were all unanimous that this shark was something the like of which they had never dreamed of. In company with the local Fisheries Inspector I questioned many of the men very closely and they all agreed as to the gigantic stature of the beast. But the lengths they gave were, on the whole, absurd. I mention them, however, as a indication of the state of mind which this unusual giant had thrown them into. And bear in mind that these were men who were used to the sea and all sorts of weather, and all sorts of sharks as well. One of the crew said the shark was "three hundred feet [90 m] long at least"! Others said it was as long as the wharf on which we stoodabout 115 feet [35 m]! They affirmed that the water "boiled" over a large space when the fish swam past. They were all familiar with whales, which they had often seen passing at sea, but this was a vast shark. They had seen its terrible head which was "at least as long as the roof on the wharf shed at Nelson's Bay." Impossible, of course! But these were prosaic and rather stolid men, not given to 'fish stories' nor even to talking about their catches. Further, they knew that the person they were talking to (myself) had heard all the fish stories years before! One of the things that impressed me was that they all agreed as to the ghostly whitish color of the vast fish. The local Fisheries Inspector of the time, Mr Paton, agreed with me that it must have been something really gigantic to put these experienced men into such a state of fear and panic."

Others have countered that such recent estimates are inaccurate, and "claims of post-Pliocene C. megalodon ... are erroneous" and based on outdated methodology. Roesch and others also note that Megalodons were probably coastal sharks, and that deep-sea survival is extremely unlikely.

There is a theory that Carcharodon megalodon when adult fed largely on whales and went extinct as the polar seas became too cold for sharks, letting whales go out of reach of sharks for the summer.

Around 1995 the species was proposed to be placed in the new genus Carcharocles. To date this has not been resolved.

A supposed surviving population of Megalodon sharks has been the subject of fictional novels, including several by Steve Alten, and a feature-length movie entitled Shark Attack 3: Megaldon.

Conservation status: Fossil

Issue #196

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Ocicat

The Ocicat is a new and still-rare breed of cat which has spots resembling a 'wild' cat and the temperament of a domestic animal, named for its resemblance to the ocelot.

Sleeping Ocicat

Despite its appearance, there is no 'wild' DNA in the Ocicat's genepool. The species is actually a mixture of Siamese and Abyssinian, and later American Shorthairs (silver tabbies) were added to the mix for their silver colour and distinct markings.

The first breeder of Ocicats was Virginia Daly, of Berkley, Michigan, who attempted to breed an Abyssinian-pointed Siamese in 1964. The first generation of kittens appeared Abyssinian, but the surprising result in the second generation was a spotted kitten, Tonga, nicknamed an 'ocicat' by the breeder's daughter. Tonga was neutered and sold as a pet, but further breedings of his parents produced more spotted kittens, and became the base of a separate Ocicat breeding program.

There are twelve separate colour/pattern combinations registered for ocicats, and these fall into five larger groups - chocolate, cinnamon, tawny, silver and dilute. Ocicats must not have cream/red coloration or they are disqualified from showing.

Issue #197

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Western Grey Kangaroo

The Western Grey Kangaroo (Macropus fuliginosis) is a large and very common macropod, found across almost the entire southern part of Australia, from just south of Shark Bay to coastal South Australia, western Victoria, and the entire Murray-Darling Basin in New South Wales and Queensland.

Western Grey Kangaroo, Macropus fuliginosis, with joey

Long known to the Aboriginal people of Australia, for Europeans, the Western Grey was the centre of a great deal of sometimes comical taxonomic confusion for almost 200 years. It was first noted by European settlers when the great explorer Matthew Flinders landed on Kangaroo Island in 1802. Flinders shot several for food but assumed that they were Eastern Grey Kangaroos. In 1803 French explorers captured several Kangaroo Island Western Greys and shipped them home to Paris, where they lived in the zoological gardens for some years. Eventually, researchers at the Paris Museum of Natural History recognised that these animals were indeed different and formally described the species as Macropus fuliginosus in 1817. Unfortunately, for reasons that remain unclear, it was described as native to Tasmania!

There the matter rested for over 100 years, and it was not until 1917 that researchers realised that the "Forester Kangaroo" of Tasmania was in fact Macropus giganteus, the same Eastern Grey Kangaroo that was, and still is, widespread in the more fertile south-eastern part of the mainland. By 1971, it was understood that the Kangaroo Island species was the same as the kangaroos of southern Western Australia, and that this population exended through much of the eastern part of the continent s well. For a time, three subspecies were described, two on the mainland and one on Kangaroo Island. Finally, by the early 1990s, the current understanding energed.

There are two subspecies of the Western Grey: Macropus fuliginosus fuliginosus of Kangaroo Island, and Macropus fuliginosus melanops, which has a range of different forms that intergrade clinallly from west to east.

The Western Grey is not found in the tropical north or the fertile south-east of Australia, and the Eastern Grey does not extend beyond the NSW-South Australia border, but the two species are both common in the Murray-Darling Basin area. They never interbreed in the wild, although it has proved possible to produce hybrids between Eastern Grey females and Western Grey males in captivity.

The Western Grey Kangaroo is also referred to as a Stinker, Black-faced Kangaroo, Mallee Kangaroo or Sooty Kangaroo.

Issue #198

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Wild Turkey

The Wild Turkey (Meleagris gallopavo) is a large gamebird, one of a number of species of turkey.

Adults have a bluish featherless small head, a red throat, long legs and a dark body. They have a long dark fan-shaped tail. Their wings are a glossy bronze. As with many other species of the Galliformes, they exhibit strong sexual dimorphism - males have red wattles on the throat and neck and are significantly larger than females.

Male Wild Turkey, Meleagris gallopavo

The breeding habitat is wooded areas, usually with clearings, across most of the United States and parts of southern Canada, where they are permanent residents. They nest on the ground at the bottom of a tree, shrub or in tall grass.

Male birds display for females by puffing out their feathers, spreading out their tails, inflating the wattles on their neck and drooping wings. Males are polygamous, and they form territories that may have as many as 5 hens within.

The birds forage on the ground or climb shrubs to eat berries. They are omnivorous, eating acorns, seeds, berries, roots and insects, sometimes snakes, frogs or salamanders.

They are relatively weak fliers and will escape on foot if possible; at night, these birds roost in trees. They are capable of achieving speeds of 50 miles per hour (80 kilometers per hour) in flight.

Only the males "gobble"; the females cluck. The males also emit a low-pitched thumping sound. This bird was Benjamin Franklin's preference as the national bird for the United States. It has been adopted as the official game bird of South Carolina, Alabama, Oklahoma and Massachusetts.

Wild turkey from the Eastern part of USA

It is the traditional main dish for the Thanksgiving holiday, which is held in November in the United States and October in Canada, but of course it is now normally replaced by the domesticated turkey. The Aztecs domesticated the southern Mexican form, M. g. gallopavo, one of the six subspecies.

The range and numbers of this bird had decreased at the beginning of the 20th century due to hunting and loss of habitat, and game officials made efforts to protect and encourage the breeding of the surviving wild population. As the wild turkey's numbers rebounded in the 1980s and 1990s, hunting was legalized in most states.

Issue #199

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Freshwater crocodile

The Freshwater Crocodile, Crocodylus johnstoni, also known as Johnston's Crocodile or Freshies, are found in the northern regions of Australia. They are found in the states of Western Australia, Queensland, and the Northern Territory. Main habitats include freshwater wetlands, billabongs, rivers, and creeks. It competes poorly with Saltwater crocodiles (C. porosus) but is saltwater tolerant.

Freshwater Crocodile, Crocodylus johnstoni

Appearance

The Australian freshwater crocodile is a relatively small crocodilian which rarely exceeds 2.5 to 3 m in the wild and takes many years (at least 30) to reach this size. Females general reach a maximum size of 2.0 to 2.1 metres. The shape of the snout is unusually narrow and tapering, lined with numerous sharp teeth (unlike the blunter teeth found in larger C. porosus). The body colour is light brown with darker bands on the body and tail - these tend to be broken up near the neck. Some individuals possess distinct bands or speckling on the snout. Body scales are relatively large, with wide, closely-knit armoured plates on the back. Rounded, pebbly scales cover the flanks and outsides of the legs.

Diet

The shape of the snout, like that of the gharial, suggests a primary adaptation to a piscivorous (fish-based) diet, and fish are certainly handled with ease. However, a wide variety of other prey items are often taken - generally invertebrates and small vertebrates, especially when younger. Larger individuals may take terrestrial species. C. johnstoni favours a sit-and-wait hunting strategy, snatching prey up with a lightning-fast sideways movement of the head. It rarely feeds during the dry season because of a lack of prey availability, low temperatures at night and a reduction in available habitat due to drying of pools and rivers.

Breeding

Males reach sexual maturity around 1.5 m in length, with females being only slightly smaller. Courtship occurs in the early months of the dry season (around May) and nesting generally occurs between July and September. Females dig hole nests in sand embankments, exposed after the wet season water levels fall.

Research has found that all females within a particular population usually nest within the same three week period - behaviour described as 'pulse' nesting. They may also nest in groups, with many nests being laid in close proximity (some females even dig up the clutches of other females when nest density becomes very high).

Eggs are normally laid at night 6 weeks after mating, at a depth of 12 to 20 cm below the surface - too close to the surface and they risk being overheated from the sun. Incubation temperatures of between 30 and 33 degrees are desirable. Clutch size averages 13 eggs, but can range from 4 to 20. The incubation period is usually between 75 to 85 days (maximum range 65 to 95 days). Studies on temperature effects have shown that eggs incubated at 32°C produce male embryos, whereas those a couple of degrees above and below this produce female embryos - however, greater sexual differentiation seems to occur with fluctuating nest temperatures.

Varanus lizards and feral pigs are major predators of eggs during this period, when neither parent guards the nest. Varanids can easily find nests laid within 24 to 48 hours. On average for all nests laid, under one third of the eggs survive to hatching. The female parents return at the end of the incubation period and wait for the neonates to begin calling. They may then carry the newly-hatched juveniles to the water in their mouths, although the nests will still hatch out without the female being present. Adult females stay close to and protect the small crocodiles for a variable period following this, but protection is not as long as the sympatric C. porosus. Disturbance is more likely to result in the female abandoning the nest and her offspring.

Cannibalism has been reported, often due to a scarcity of food. Only 1% of these hatchlings will survive to reach maturity, and in some years predation pressures are so high that it is unlikely that any new animals are recruited into the adult population. In some years, early rains at the end of the dry season can destroy almost all the nests through flooding. Juveniles which survive to maturity have been found returning to the same breeding and nesting areas.

Conservation

Good population data exist for this species, as well as the sympatric C. porosus. Hunting has been less of a problem than with C. porosus, mainly due to the presence of ventral osteoderms in the belly scales of adults. Long-term aboriginal hunting did not significantly affect the population, but advances in tanning processes at the end of the 1950s meant that C. johnstoni skins could be utilised when C. porosus populations became depleted. This hunting caused a widespread reduction in the population until protection measures were implemented in the 1960s and 1970s.

Although a small amount of illegal poaching and killing no doubt persists, the major threat at the moment is the omnipresent one of habitat destruction. Recently, invasive species such as cane toads (Bufo marinus) have led to mortality of adults and presumably juveniles in otherwise healthy populations. The threat of these toads has not yet been ascertained properly, although it is likely that only dwarf populations are under any real long-term threat.

Populations have recently recovered to a significant extent. Small-scale farming and ranching programs exist for commercial purposes, and monitoring and management studies which were initiated in the 1970s are still ongoing. Valuable long-term research is being conducted upon the population dynamics of this species, together with other studies looking at biology, physiology and development. Population estimates vary, as the species can be difficult to survey effectively, but it is not unreasonable to assume that there are at least 100,000 individuals in the wild.

Conservation status: Lower risk (lc)

Issue #200

poon cho tang SG

Death's-head Hawkmoth

The name Death's-head Hawkmoth usually refers to one of the two species (A. atropos and A. styx) of moth in the Acherontia genus. Found throughout the Middle East and the Mediterranean region, and increasingly as far north as southern Great Britain due to recently mild British winters, this moth is easily distinguishable by a skull-shaped pattern on its back.

Death's-head Hawkmoth, Acherontia atropos

The skull pattern has helped the moth earn a negative reputation, such as associations with the supernatural and evil, and was featured in the movies The Silence of the Lambs and Un Chien Andalou. Numerous superstitions also claim that the moth brings bad luck to the house it flies into.

The moth also has numerous other unique features, such as an ability to emit a loud squeak if irritated, and is commonly observed raiding beehives for honey. There is some contradiction in reports on whether the moth is able to enter a hive and feed undisturbed, or meets resistance and fights using its wings, usually being defeated.

Various "Death's head" patternts on the Acherontia atropos moth.

The A. atropos is also very large, with a wingspan of 90-130 mm, being the largest moth in some of the regions it is found in.

The species names atropos and styx are both death-related. The first refers to the member of the Moirae who cuts the threads of life of all beings in Greek mythology, and the second to the river of the dead also in Greek mythology.

The British entomological journal Atropos takes its name from this species.

Conservation status: Unknown

Issue #201

poon cho tang SG

Blue catfish

The Blue catfish (Ictalurus furcatus) is one of the largest species of North American catfish. The current angling world record weighed 121.5 pounds (55.1 kg) and was caught in Lake Texoma in Texas on 16 January 2004. Though it has not yet been officially documented as a world record, a 124 pound blue catfish was caught on May 22, 2005, in the Mississippi River.

Blue catfish, Ictalurus furcatus

Blue catfish are distributed primarily in the Mississippi River drainage including the Missouri, Ohio, Tennessee, and Arkansas rivers. These large catfish have also been introduced in a number of reservoirs and rivers, notably the Santee-Cooper Reservoir in South Carolina and the James River in Virginia.

Blue catfish are opportunistic predators and will eat any species of fish they can catch, along with crayfish, freswater mussels, frogs, and other readily available aquatic food sources. Catching their prey becomes all the more easy if it is already wounded or dead, and blue cats are noted for feeding beneath marauding schools of striped bass in open water in reservoirs or feeding on wounded baitfish that have been washed through dam spillways or power generation turbines.

Due to their opportunistic nature, blue catfish will usually take advantage of readily accessible food in a variety of situations, which from the angler's perspective makes cutbaits, deadbaits, and even stinkbaits an excellent choice to target these fish.

Blue cats will also respond well to live baits, with live river herring and shad usually a top choice followed by large shiner minnows, sunfish, suckers, and carp. All of the above baits can be used as fresh cutbaits with good success and freshwater drum also work well in this capacity. Generally a fairly large piece of cutbait (4-12 inches long) on a fairly large hook (3/0 to 9/0) is a good choice in rivers or reservoirs where large blue cats (20 pounds and up) are a possibility. Depending on current conditions sinkers ranging from 1/2 to 6 or 8 oz. may be required with 1-2 oz. a good choice for many situations.

To catch large blue catfish in rivers the more current the better usually, although fishing along current edges and breaks is often a good option. Blue catfish tend to favor deeper water in larger rivers and reservoirs, but will make feeding and spawning forays into relatively shallow water.

Issue #202

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