Monday, November 12, 2012

Lion study




The lion (Panthera leo) is one of the four big cats in the genus Panthera and a member of the family Felidae. With some males exceeding 250 kg (550 lb) in weight, it is the second-largest living cat after the tiger. Wild lions currently exist in sub-Saharan Africa and in Asia, with an endangered remnant population in Gir Forest National Park in India, having disappeared from North Africa and Southwest Asia in historic times. Until the late Pleistocene, about 10,000 years ago, the lion was the most widespread large land mammal after humans. They were found in most of Africa, across Eurasia from western Europe to India, and in the Americas from the Yukon to Peru. The lion is a vulnerable species, having seen a major population decline of 30–50% over the past two decades[date missing] in its African range. Lion populations are untenable outside designated reserves and national parks. Although the cause of the decline is not fully understood, habitat loss and conflicts with humans are currently the greatest causes of concern. Within Africa, the West African lion population is particularly endangered.
Lions live for 10–14 years in the wild, while in captivity they can live longer than 20 years. In the wild, males seldom live longer than 10 years, as injuries sustained from continual fighting with rival males greatly reduce their longevity. They typically inhabit savanna and grassland, although they may take to bush and forest. Lions are unusually social compared to other cats. A pride of lions consists of related females and offspring and a small number of adult males. Groups of female lions typically hunt together, preying mostly on large ungulates. Lions are apex and keystone predators, although they scavenge as opportunity allows. While lions do not typically hunt humans, some have been known to do so. Sleeping mainly during the day, lions are primarily nocturnal, although bordering on crepuscular in nature.
Highly distinctive, the male lion is easily recognised by its mane, and its face is one of the most widely recognised animal symbols in human culture. Depictions have existed from the Upper Paleolithic period, with carvings and paintings from the Lascaux and Chauvet Caves, through virtually all ancient and medieval cultures where they once occurred. It has been extensively depicted in sculptures, in paintings, on national flags, and in contemporary films and literature. Lions have been kept in menageries since the time of the Roman Empire, and have been a key species sought for exhibition in zoos over the world since the late 18th century. Zoos are cooperating worldwide in breeding programs for the endangered Asiatic subspecies.
(For more: Wikipedia )

Saturday, September 15, 2012

Cheetah study




The cheetah (Acinonyx jubatus) is a large-sized feline (family Felidae, subfamily Felinae) inhabiting most of Africa and parts of the Middle East. It is the only extant member of the genus Acinonyx. The cheetah can run faster than any other land animal— as fast as 112 to 120 km/h (70 to 75 mph) in short bursts covering distances up to 500 m (1,600 ft), and has the ability to accelerate from 0 to over 100 km/h (62 mph) in three seconds.
This cat is also notable for modifications in the species' paws. It is one of the few felids with semi-retractable claws.

The cheetah has unusually low genetic variability. This is accompanied by a very low sperm count, motility, and deformed flagella. Skin grafts between unrelated cheetahs illustrate the former point in that there is no rejection of the donor skin. It is thought that the species went through a prolonged period of inbreeding following a genetic bottleneck during the last ice age. This suggests that genetic monomorphism did not prevent the cheetah from flourishing across two continents for thousands of years.
The cheetah likely evolved in Africa during the Miocene epoch (26 million to 7.5 million years ago), before migrating to Asia. Recent research has placed the last common ancestor of all existing populations as living in Asia 11 million years ago, which may lead to revision and refinement of existing ideas about cheetah evolution.


Cheetah at the Maasai Mara National Reserve
The now-extinct species include: Acinonyx pardinensis (Pliocene epoch), much larger than the modern cheetah and found in Europe, India, and China; Acinonyx intermedius (mid-Pleistocene period), found over the same range. The extinct genus Miracinonyx was extremely cheetah-like, but recent DNA analysis has shown that Miracinonyx inexpectatus, Miracinonyx studeri, and Miracinonyx trumani (early to late Pleistocene epoch), found in North America and called the "North American cheetah" are not true cheetahs, instead being close relatives to the cougar.
(Source: Wikipedia)

Thursday, August 2, 2012

Giraffe study


The giraffe (Giraffa camelopardalis) is an African even-toed ungulate mammal, the tallest living terrestrial animal and the largest ruminant. Its binomial name refers to its camel-like face and the patches of color on its fur. Its chief distinguishing characteristics are its extremely long neck and legs, its horn-like ossicones and its distinctive markings. It stands 5–6 m (16–20 ft) tall and has an average weight of 1,600 kg (3,500 lb) for males and 830 kg (1,800 lb) for females. It is classified under the family Giraffidae, along with its closest extant relative, the okapi. There are nine subspecies, which are distinguished by their coat patterns.
The giraffe's scattered range extends from Chad in the north to South Africa in the south, and from Niger in the west to Somalia in the east. Giraffes usually inhabit savannas, grasslands, and open woodlands. Their primary food source is acacia leaves, which they can browse at heights that most other herbivores cannot reach. Giraffes are preyed on by lions, and calves are also targeted by leopards, spotted hyenas and wild dogs. Adult giraffes do not have strong social bonds, though they do gather in loose aggregations if they happen to be moving in the same general direction. Males establish social hierarchies through "necking", which are combat bouts where the neck is used as a weapon. Dominant males gain mating access to females, who bear the sole responsibility for raising the young.
The giraffe has intrigued various cultures, both ancient and modern, for its peculiar appearance, and has often been featured in paintings, books and cartoons. It is classified by the International Union for Conservation of Nature (IUCN) as Least Concern, but has been extirpated from many parts of its former range, and some subspecies are classified as Endangered. Nevertheless, giraffes are still found in numerous national parks and game reserves.
(Source: Wikipedia)

Thursday, July 19, 2012

Ladybug study




The Coccinellidae are a family of beetles, known variously as ladybirds (UK, Ireland, Australia, Sri Lanka, Pakistan, South Africa, New Zealand, India, Malta, some parts of Canada and the US), or ladybugs (North America). When they need to use a common name, entomologists widely prefer the names ladybird beetles or lady beetles as these insects are not true bugs. Lesser-used names include God's cow, ladyclock, lady cow, and lady fly.

Coccinellids are small insects, ranging from 1 mm to 10 mm (0.04 to 0.4 inches), and are commonly yellow, orange, or scarlet with small black spots on their wing covers, with black legs, head and antennae. Such color patterns vary greatly however; for example, a minority of species, such as Vibidia duodecimguttata, a twelve-spotted species. has whitish spots on a brown background.

In some species the spots are so large that they merge, leaving the remaining bright colours as spots on a black background. Many coccinellid species are mostly, or entirely, black, grey, or brown and may be difficult for non-entomologists to recognize as coccinellids at all. Conversely, non-entomologists might easily mistake many other small beetles for coccinellids. For example the tortoise beetles, like the ladybird beetles, look similar because they are shaped so that they can cling to a flat surface so closely that ants and many other enemies cannot grip them.

Coccinellids are found worldwide, with over 5,000 species described, more than 450 native to North America alone.

The Coccinellidae are generally considered useful insects, because many species feed on aphids or scale insects, which are pests in gardens, agricultural fields, orchards, and similar places. However, some species do have unwelcome effects. Among these the most prominent are the subfamily Epilachninae, which are plant eaters. Usually Epilachninae are only mild agricultural pests, eating the leaves of grain, potatoes, beans and various other crops, but their numbers can increase explosively in years when their natural enemies are few, such as parasitoid wasps that attack their eggs. When that happens they can do major crop damage. They occur in practically all the major crop producing regions of temperate and tropical countries.

Coccinellids are typically predators of Hemiptera such as aphids and scale insects, though larvae and eggs of their own species can also be important resources when alternative prey are scarce.

Members of the subfamily Epilachninae are herbivores, and can be very destructive agricultural pests (e.g., the Mexican bean beetle). While predatory species are often used as biological control agents, introduced species of coccinellidae (such as Harmonia axyridis or Coccinella septempunctata in North America) out-compete and displace native coccinellids and become pests in their own right.

The main predators of coccinellids are usually birds, but they are also the prey of frogs, wasps, spiders, and dragonflies. The bright colours of many coccinellids discourage some potential predators from making a meal of them. This phenomenon is called aposematism and works because predators learn by experience to associate certain prey phenotypes with a bad taste. A further defense known as "Reflex bleeding" exists in which an alkaloid toxin is exuded through the joints of the exoskeleton, triggered by mechanical stimulation (such as by predator attack) in both larval and adult beetles, deterring feeding.

(Source: Wikipedia )

Sunday, July 15, 2012

Kingfisher study



Kingfishers are a group of small to medium sized brightly coloured birds in the order Coraciiformes. They have a cosmopolitan distribution, with most species being found in the Old World and Australia. The group is treated either as a single family, Alcedinidae, or as a suborder Alcedines containing three families, Alcedinidae (river kingfishers), Halcyonidae (tree kingfishers), and Cerylidae (water kingfishers). There are roughly 90 species of kingfisher. All have large heads, long, sharp, pointed bills, short legs, and stubby tails. Most species have bright plumage with little differences between the sexes. Most species are tropical in distribution, and a slight majority are found only in forests. They consume a wide range of prey as well as fish, usually caught by swooping down from a perch. Like other members of their order they nest in cavities, usually tunnels dug into the natural or artificial banks in the ground. A few species, principally insular forms, are threatened with extinction.
The smallest species of kingfisher is the African Dwarf Kingfisher (Ispidina lecontei), which averages at 10.4 g and 10 cm (4 inches). The largest overall is the Giant Kingfisher (Megaceryle maxima), at an average of 355 g (13.5 oz) and 45 cm (18 inches). However, the familiar Australian kingfisher known as the Laughing Kookaburra (Dacelo novaeguineae) may be the heaviest species, since large individuals exceeding 450 g (1 lb) are not rare.
The plumage of most kingfishers is bright, with green and blue being the most common colours. The brightness of the colours is neither the product of iridescence (except in the American kingfishers) or pigments, but is instead caused by the structure of the feathers, which causes scattering of blue light (the Tyndall effect). In most species there are no differences between the sexes; when there are differences they are quite small (less than 10%).
The kingfishers have a long, dagger-like bill. The bill is usually longer and more compressed in species that hunt fish, and shorter and more broad in species that hunt prey off the ground. The largest and most atypical bill is that of the Shovel-billed Kookaburra, which is used to dig through the forest floor in search of prey. They generally have short legs, although species that feed on the ground have longer tarsi. Most species have four toes, three of which are forward pointing.
The irises of most species are dark brown. The kingfishers have excellent vision; they are capable of binocular vision and are thought in particular to have good colour vision. They have restricted movement of their eyes within the eye sockets, instead using head movements in order to track prey. In addition they are able to compensate for the refraction of water and reflection when hunting prey underwater, and are able to judge depth underwater accurately. They also have nictitating membranes that cover the eyes when they hit the water in order to protect them; in the Pied Kingfisher has a bony plate which slides across the eye when the bird hits the water.
(Source: Wikipedia)

Saturday, June 2, 2012

Praying mantis study

Mantodea (or mantises) is an order of insects that contains approximately 2,200 species in 15 families worldwide in temperate and tropical habitats. Most of the species are in the family Mantidae. Historically, the term mantid was used to refer to any member of the order because for most of the past century, only one family was recognized within the order; technically, however, the term only refers to this one family, meaning the species in the other 14 recently established families are not mantids, by definition (i.e., they are empusids, or hymenopodids, etc.), and the term "mantises" should be used when referring to the entire order.

A colloquial name for the order in the United States is "praying mantises", because of the typical "prayer-like" stance, although the eggcorn "preying mantis" is sometimes used since mantises are predatory. In Europe and other regions, however, the name "praying mantis" refers to only a single species, Mantis religiosa. The closest relatives of mantises are the orders Isoptera (termites) and Blattodea (cockroaches), and these three groups together are sometimes ranked as an order rather than a superorder. They are sometimes confused with phasmids (stick/leaf insects) and other elongated insects such as grasshoppers and crickets.

Mantises have two grasping, spiked forelegs ("raptorial legs") in which prey items are caught and held securely. Located at the base of the femur are a set of discoidal spines, usually four in number but ranging from zero to as many as five depending on the species. These spines are preceded by a number of tooth-like tubercles, which, along with a similar series of tubercles along the tibia and the apical claw near its tip, give the foreleg of the mantis its grasp on its prey. The foreleg ends in a delicate tarsus made of between four and five segments and ending in a two-toed claw with no arolium and used as a walking appendage.

The mantis thorax consist of a prothorax, a mesothorax, and a metathorax. In virtually all species the prothorax, to which are attached the head and forelegs, is much longer than the other two thoraces (the sole exceptions are the seven members of the Mantoididae family). The prothorax is also flexibly articulated, allowing for a wide range of movement of the front limbs while the remainder of the body remains more or less immobile.

The articulation of the head is also remarkably flexible, permitting nearly 300 degrees of movement in some species, allowing for a great range of vision (their compound eyes may contain up to 10,000 ommatidia and have a large binocular field of vision). The dark spot on each eye is a pseudopupil. As their hunting relies heavily on vision, they are primarily diurnal, but many species will fly at night, especially males in search of less-mobile females whom they can detect through pheromones. Flying at night allows these males to avoid many diurnal bird predators, and many mantises also have an auditory thoracic organ that assists them as they attempt to avoid capture by bats by detecting the presence of the bat's echolocation sounds and responding evasively.

Mantises have a wide range of wing morphologies and can be loosely categorized as being either macropterous (long-winged), brachypterous (short-winged), micropterous (vestigial-winged), or as apterous (wingless). If not wingless, a mantis will have two sets of wings: the outer wings, called the foreseeing or tegmina, are usually narrow, opaque, and leathery and function as camouflage and as a shield for the inner wings, or hindwings—it is this much more delicate, broad, and transparent set that is actually used for flight, though in many of the brachypterous species these wings are only capable of producing minimal and very temporary lift and in the micropterous species they have no flight-related function at all. Also, in many macropterous species, the female will have much shorter wings than the male and will only rarely take flight.

The abdomen of all mantises consist of ten tergites with a corresponding set of nine sternites visible in males and seven visible in females. The slim abdomen of most males allows them to take flight more easily while the thicker abdomen of the females houses the reproductive machinery for generating the ootheca. The abdomen of both sexes ends in a pair of cerci.
(Source:Wikipedia)

Tuesday, May 29, 2012

Turtle study


Turtles are reptiles of the order Testudines (the crown group of the superorder Chelonia), characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield. "Turtle" may either refer to the Testudines as a whole, or to particular Testudines which make up a form taxon that is not monophyletic.

The order Testudines includes both extant (living) and extinct species. The earliest known turtles date from 215 million years ago, making turtles one of the oldest reptile groups and a more ancient group than lizards, snakes and crocodiles. Of the many species alive today, some are highly endangered.

Like other reptiles, turtles are ectotherms—their internal temperature varies according to the ambient environment, commonly called cold-blooded. However, leatherback sea turtles have noticeably higher body temperature than surrounding water because of their high metabolic rate.

Like other amniotes (reptiles, dinosaurs, birds, and mammals), they breathe air and do not lay eggs underwater, although many species live in or around water. The largest turtles are aquatic.

The largest living chelonian is the leatherback sea turtle (Dermochelys coriacea), which reaches a shell length of 200 centimetres (6.6 ft) and can reach a weight of over 900 kilograms (2,000 lb). Freshwater turtles are generally smaller, but with the largest species, the Asian softshell turtle Pelochelys cantorii, a few individuals have been reported up to 200 centimetres (6.6 ft). This dwarfs even the better-known alligator snapping turtle, the largest chelonian in North America, which attains a shell length of up to 80 centimetres (2.6 ft) and weighs as much as 113.4 kilograms (250 lb). Giant tortoises of the genera Geochelone, Meiolania, and others were relatively widely distributed around the world into prehistoric times, and are known to have existed in North and South America, Australia, and Africa. They became extinct at the same time as the appearance of man, and it is assumed humans hunted them for food. The only surviving giant tortoises are on the Seychelles and Galápagos Islands, and can grow to over 130 centimetres (51 in) in length, and weigh about 300 kilograms (660 lb).

The largest ever chelonian was Archelon ischyros, a Late Cretaceous sea turtle known to have been up to 4.6 metres (15 ft) long.

The smallest turtle is the speckled padloper tortoise of South Africa. It measures no more than 8 centimetres (3.1 in) in length and weighs about 140 grams (4.9 oz). Two other species of small turtles are the American mud turtles and musk turtles that live in an area that ranges from Canada to South America. The shell length of many species in this group is less than 13 centimetres (5.1 in) in length.
(Source: Wikipedia)

Monday, May 28, 2012

Hippo study


The hippopotamus (Hippopotamus amphibius), or hippo, from the ancient Greek for "river horse" (ἱπποπόταμος), is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae (the other is the Pygmy Hippopotamus.) After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest extant artiodactyl.
The hippopotamus is semi-aquatic, inhabiting rivers, lakes and mangrove swamps, where territorial bulls preside over a stretch of river and groups of 5 to 30 females and young. During the day they remain cool by staying in the water or mud; reproduction and childbirth both occur in water. They emerge at dusk to graze on grass. While hippopotamuses rest near each other in the water, grazing is a solitary activity and hippos are not territorial on land.
Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, their closest living relatives are cetaceans (whales, porpoises, etc.) from which they diverged about 55 million years ago. The common ancestor of whales and hippos split from other even-toed ungulates around 60 million years ago. The earliest known hippopotamus fossils, belonging to the genus Kenyapotamus in Africa, date to around 16 million years ago.
The hippopotamus is recognizable by its barrel-shaped torso, enormous mouth and teeth, nearly hairless body, stubby legs and tremendous size. It is the third largest land mammal by weight (between 1½ and 3 tonnes), behind the white rhinoceros (1½ to 3½ tonnes) and the three species of elephant (3 to 9 tonnes). The hippopotamus is one of the largest quadrupeds (four legged mammals)  and despite its stocky shape and short legs, it can easily outrun a human. Hippos have been clocked at 30 km/h (19 mph) over short distances. The hippopotamus is one of the most aggressive creatures in the world and is often regarded as one of the most dangerous animals in Africa. There are an estimated 125,000 to 150,000 hippos throughout Sub-Saharan Africa; Zambia (40,000) and Tanzania (20,000–30,000) possess the largest populations.They are still threatened by habitat loss and poaching for their meat and ivory canine teeth. There is also a colony of non-zoo hippos in Colombia introduced by Pablo Escobar. (Source: Wikipedia)

Thursday, May 24, 2012

Elephant study

Elephants are large land mammals in two extant genera of the family Elephantidae: Elephas and Loxodonta, with the third genus Mammuthus extinct. Three living species of elephant are recognized: the African bush elephant, the African forest elephant and the Indian or Asian elephant; although some group the two African species into one and some researchers also postulate the existence of a fourth species in West Africa. All other species and genera of Elephantidae are extinct. Most have been extinct since the last ice age, although dwarf forms of mammoths might have survived as late as 2,000 BCE. Elephants and other Elephantidae were once classified with other thick-skinned animals in a now invalid order, Pachydermata
Elephants are the largest living land animals on Earth today. The elephant's gestation period is 22 months, the longest of any land animal. At birth, an elephant calf typically weighs 105 kilograms (230 lb). They typically live for 50 to 70 years, but the oldest recorded elephant lived for 82 years. The largest elephant ever recorded was shot in Angola in 1955. This male weighed about 10,900 kg (24,000 lb), with a shoulder height of 3.96 metres (13.0 ft), 1 metre (3.3 ft) taller than the average male African elephant. The smallest elephants, about the size of a calf or a large pig, were a prehistoric species that lived on the island of Crete during the Pleistocene epoch.

Elephants are a symbol of wisdom in Asian cultures and are famed for their memory and intelligence; their intelligence level is thought to be comparable to that of dolphins and primates. Aristotle once said the elephant was "the beast which passeth all others in wit and mind." The word "elephant" has its origins in the Greek ἐλέφας, meaning "ivory" or "elephant".

Healthy adult elephants have no natural predators, although lions may take calves or weak individuals. They are, however, threatened by human intrusion and poaching.

The African elephant genus contains two living species; whereas the Asian elephant species is the only surviving member of the Asian elephant genus, but can be divided into four subspecies. The African and the Asian elephants diverged from a common ancestor some 7.6 million years ago.
(Source: Wikipedia)

Wednesday, May 23, 2012

Fly study

True flies are insects of the order Diptera (from the Greek di = two, and ptera = wings). They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax. Apart from secondarily flightless insects (including some flies), the only other order of insects with any form of halteres are the Strepsiptera, and theirs are on the mesothorax, with the flight wings on the metathorax.

Flies are adapted for aerial movement and typically have short and streamlined bodies. The first tagma of the fly, the head, consists of ocelli, antennae, compound eyes, and the mouthparts (the labrum, labium, mandible and maxilla make up the mouthparts). The second tagma, the thorax, bears the wings and contains the flight muscles on the second segment, which is greatly enlarged; the first and third segments have been reduced to collar-like structures. The third segment of the thorax bears the halteres, which help to balance the insect during flight. A further adaptation for flight is the reduction in number of the neural ganglia, and concentration of nerve tissue in the thorax, a feature that is most extreme in the highly derived Muscomorpha infraorder.A scan of a house fly taken at 40 magnifications under a scanning electron microscope

Flies have a mobile head with eyes and in most cases have large compound eyes on the sides of the head, with three small ocelli on the top. The antennae take a variety of forms, but are often short, which reduces drag while flying.

Because no species of fly has teeth or any other organ or limb that allows them to eat solid foods, flies consume only liquid food or finely granular foods, such as pollen, and their mouthparts and digestive tracts show various modifications for such diets. Female Tabanidae use knife-like mandibles and maxillae to make a cross-shaped incision in the hosts' skin and then lap up the blood. The gut includes large diverticulae, allowing the insect to store small quantities of liquid after a meal.

For detailed anatomy explore  which uses examples from the 4 major fly groups (Lower Diptera, Lower Brachycera, Acalyptrate, Calyptrate) representing different anatomical expressions.

(Source: Wikipedia)

Tuesday, May 22, 2012

Rhino study

Rhinoceros often abbreviated as rhino, is a group of five extant species of knee-less, odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia.

The rhinoceros family is characterized by its large size (one of the largest remaining megafauna), with all of the species able to reach one tonne or more in weight; a herbivorous diet; a thick protective skin, 1.5–5 cm thick, formed from layers of collagen positioned in a lattice structure; relatively small brains for mammals this size (400–600 g); and a large horn. They generally eat leafy material, although their ability to ferment food in their hindgut allows them to subsist on more fibrous plant matter, if necessary. Unlike other perissodactyls, the African species of rhinoceros lack teeth at the front of their mouths, relying instead on their powerful premolar and molar teeth to grind up plant food.

Rhinoceros are killed by humans for their horns, which are bought and sold on the black market, and which are used by some cultures for ornamental or (pseudo-scientific) medicinal purposes. The horns are made of keratin, the same type of protein that makes up hair and fingernails. Both African species and the Sumatran rhinoceros have two horns, while the Indian and Javan rhinoceros have a single horn.
(Source: Wikipedia)

Monday, May 21, 2012

Stag beetle study

Lucanus cervus is the best-known species of stag beetle in the West (family Lucanidae), and is sometimes referred to simply as the stag beetle. It lives in holes in old trees and dead trunks, in the forest as well as in groves. Forest management, in eliminating old trees and dead wood, eliminates at the same time the habitat and food of this species. Once quite common, the population of the Lucanus cervus, along with that of other species of beetles which feed on wood, is in steep decline, and is now listed as a globally threatened/declining species.
Adults appear during late May to the beginning of August being most active in the evenings. Females lay their eggs in a piece of decaying wood. Stag beetle larvae, which are blind and shaped like a letter "C", feed on rotting wood in a variety of places, tree stumps, old trees and shrubs, rotting fence posts, compost heaps and leaf mould. The larvae have a cream-coloured soft transparent body with six orange legs, and an orange head which is very distinct from the very sharp brown pincers. They have combs in their legs which they use for communication (stridulation) with other larvae. The larvae go through several developmental stages (instars), taking 4 to 6 years to become pupae. The work of entomologist Charlie Morgan during the late 1970s discovered that the pupae of the stag beetle live in the soil for about 3 months, then emerge in summer to awkwardly fly off to mate. Adults only live for a few months feeding on nectar and tree sap. Their slow, lumbering flight, usually at dusk, makes a distinctive low-pitched buzzing sound. The males fly more readily than the females. The modern Italian word for a toy kite cervo volante (and hence the French cerf-volant) may derive from the ancient amusement of flying the beetles on a length of thread.

The natural reaction of the beetle to an approaching large object is to remain motionless making them a good photographic subject. Sexually dimorphic, the males have enlarged mandibles and are larger than the females. Although the male's mandibles seem threatening, they are too weak to be harmful. Nevertheless, females can inflict a painful bite. It is the resemblance of the male's mandibles to the horns of a stag, and their use in combat between males, much like with deer, that gives the species its scientific and common names.
 (Source: Wikipedia)

Sunday, May 20, 2012

Bee study

Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila. There are nearly 20,000 known species of bees in seven to nine recognized families, though many are undescribed and the actual number is probably higher. They are found on every continent except Antarctica, in every habitat on the planet that contains insect-pollinated flowering plants.

Bees are adapted for feeding on nectar and pollen, the former primarily as an energy source and the latter primarily for protein and other nutrients. Most pollen is used as food for larvae.

Bees have a long proboscis (a complex "tongue") that enables them to obtain the nectar from flowers. They have antennae almost universally made up of 13 segments in males and 12 in females, as is typical for the superfamily. Bees all have two pairs of wings, the hind pair being the smaller of the two; in a very few species, one sex or caste has relatively short wings that make flight difficult or impossible, but none are wingless.

The smallest bee is Trigona minima, a stingless bee whose workers are about 2.1 mm (5/64") long. The largest bee in the world is Megachile pluto, a leafcutter bee whose females can attain a length of 39 mm (1.5"). Members of the family Halictidae, or sweat bees, are the most common type of bee in the Northern Hemisphere, though they are small and often mistaken for wasps or flies.

The best-known bee species is the European honey bee, which, as its name suggests, produces honey, as do a few other types of bee. Human management of this species is known as beekeeping or apiculture.

Bees are the favorite meal of Merops apiaster, the bee-eater bird. Other common predators are kingbirds, mockingbirds, beewolves, and dragonflies.
(Source: Wikipedia)

Ant study



Ants are social insects of the family Formicidae  and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than 12,500 out of an estimated total of 22,000 species have been classified. They are easily identified by their elbowed antennae and a distinctive node-like structure that forms a slender waist.

Ants form colonies that range in size from a few dozen predatory individuals living in small natural cavities to highly organised colonies which may occupy large territories and consist of millions of individuals. These larger colonies consist mostly of sterile wingless females forming castes of "workers", "soldiers", or other specialised groups. Nearly all ant colonies also have some fertile males called "drones" and one or more fertile females called "queens". The colonies are sometimes described as superorganisms because the ants appear to operate as a unified entity, collectively working together to support the colony.

Ants have colonised almost every landmass on Earth. The only places lacking indigenous ants are Antarctica and a few remote or inhospitable islands. Ants thrive in most ecosystems, and may form 15–25% of the terrestrial animal biomass. Their success in so many environments has been attributed to their social organisation and their ability to modify habitats, tap resources, and defend themselves. Their long co-evolution with other species has led to mimetic, commensal, parasitic, and mutualistic relationships.

Ant societies have division of labour, communication between individuals, and an ability to solve complex problems. These parallels with human societies have long been an inspiration and subject of study.
Many human cultures make use of ants in cuisine, medication and rituals. Some species are valued in their role as biological pest control agents. However, their ability to exploit resources brings ants into conflict with humans, as they can damage crops and invade buildings. Some species, such as the red imported fire ant, are regarded as invasive species, establishing themselves in areas where they are accidentally introduced.

(Source: Wikipedia)