The fastest, the slowest, the highest birds

In the same way that human speed and endurance records are constantly being broken, so too the animal world's fastest, slowest and highest continues to change as naturalists discover previously unknown facts. For instance, it was widely accepted among naturalists that the white-throated spinetail swift of northeast Asia and Japan was the world's fastest bird, reaching speeds of up to 150 km/h (95 mph). But researchers have fitted speedometers to the legs of the peregrine falcon and discovered that when hunting its main prey of ducks, pigeons and other birds, it makes a 'stoop' or power dive at 160 km/h (100 mph). Sometimes this falcon knocks the head clean off its victim as it strikes it in midair with its strong talons.

Peregrine Falcon (Falco Peregrinus)

By contrast, the slowest flying (rather than hovering) bird is the American woodcock. The male's display fight has been measured at only 8 km/h (5 mph). It circles high above its woodland territory at dusk, giving twittering calls before zigzagging down to Earth on whistling wings. The combination of the slow, circling flight and the sudden descent seem to impress the females waiting on the ground.

Although birds such as kestrels and buzzards can remain stationary in midair by flying into the wind, very few birds can truly hover. Only the hummingbirds have mastered the art. They have the fastest wing beats of any bird - up to 78 beats per second - and can fly backwards as well as hover. Their short 'arm' bones, stiff wing joints and flexible shoulder joints allow them to rotate their wings in a figure of eight, and thus achieve their feats.

Other birds flap their wings very slowly - some large vultures do so only once per second. Albatrosses, using wind current to their best advantage, are able to soar over the waves for days on end with scarcely a flap of their great wings, which, with a span of up to almost 4 m (12 ft), are the longest of any living bird.

Soaring to new heights

Some animals fly fast, others fly high. The great majority of birds remain below 150 m (500 ft) for much of their lives, perhaps reaching 1500 m (5000 ft) when migrating. But bar-headed geese have been seen by mountaineers flying over the Himalayas at a height of almost 9000 m (30 000 ft). The undisputed holder of the bird altitude record is the Ruppell's griffon vulture that collided with an aircraft at 11 250 m (36 900 ft) over western Africa in 1973.

Ruppell's Griffon Vulture (Gyps rueppellii)

Birds can survive in the thin atmosphere of such heights, where humans would need oxygen masks, because their circulatory system is far more efficient at extracting oxygen than our own. The high-fliers can also cope with very low temperatures: whooper swans, for instance, have been recorded at heights where the temperature was as low as -48 degree C (-54 degree F).

Lifeguards of the deep

When Adam Maguire and his two friends Jason Maloney and Bradley Thompson went surfing at Halftide Beach, in New South Wales, early in January 1989, they found themselves in exhilarating company. For an hour or more, a school of dolphins played with them in the surf, riding in on the waves towards the beach.

But then the dolphins became agitated, splashing and turning in the water, and making loud clicking and whistling noises. It was then that Adam saw the fin of a shark speeding towards him through the waves.

Before he knew it , the shark had attacked, biting a large chunk out of his surfboard and knocking him into the water. He hit out at the shark with his fists, but it bit him in the stomach and side. Adam thought the end had come. Then the dolphins came to his rescue. They surrounded the shark and drove it out sea by ramming it with their beaks.

A friendly push

The dolphin has a reputation for being friendly to humans, and there have been many other reports of dolphins rescuing people in distress - chasing off attacking sharks, pulling drowning sailors to the surface, even guiding them to dry land. In 1945, a woman swimming off a beach in Florida was pulled under by a strong current. As she struggled to get her head above water, something pushed her violently from behind and she landed on the beach, face down. When she looked around, no one was near - but a dolphin was leaping through the waves, 6 m (20 ft) from the shore. In 1983, a Dutch helicopter pilot was helped by a dolphin after he had crashed into the Java Sea; for nine days the dolphin swam beside his rubber life raft, nudging it along until it at last reached the coast.

It is tempting to believe that we do have a special affinity with these gentle, intelligent creatures. But would an animal really take the trouble to save a human being, in some cases risking its own life in the process?

Blind instinct

Dolphin expert Dr Margaret Klinowska, of Cambridge University, believes not. She says that when attacking sharks, dolphins are only following a natural instinct to defend themselves; indeed, the presence of humans is probably coincidental. As for pulling people to the surface or pushing stranded boats along in the water, these too are probably instinctive reactions useful for the survival of the species: a dolphin is born underwater, but its mother immediately nudges it to the surface so that it can start to breathe. Perhaps the Dutch helicopter pilot's dinghy seemed to be no more than a struggling baby to the dolphin that guided it to safety.

Bugs Find Meals With Heat Sensors

The western conifer-seed bug, Leptoglossus occidentalis, has a peculiar world view. Objects stand out against the background as a result not of their color, but of their temperature — and the infrared radiation that comes with it.

Trees, warmed by their active metabolism, appear as if on fire, and their even warmer reproductive organs — in conifers, the cones — seem to glow like embers. The bugs navigate this thermoscape using infrared receptors to locate the precious seed-bearing cones they feed on.

Stephen Takács of Simon Fraser University in Burnaby, British Columbia, and several colleagues discovered the novel system after noticing that conifer-seed bugs are often attracted to warm objects in people’s homes.

To find out more, the team first measured the temperature and radiation of different pine-tree parts. Cones were as many as 27 Fahrenheit degrees warmer than needles and emitted proportionally stronger infrared radiation. Then, they tested the ability of conifer-seed bugs to perceive the radiation. Placed in cooled experimental boxes, the insects were offered the choice of a strong or weak infrared source. Insects overwhelmingly chose the strong radiation. Electron micrographs of the insects’ abdomens revealed eight bristly organs that, when irradiated, responded with frantic electrical activity. Moreover, when the presumed receptors were covered, the bugs lost their infrared “vision.”

Takács and his team suspect that many other insect species can sense infrared, and that some plants use the radiation to advertise to pollinators.
The findings were detailed in the Proceedings of the Royal Society B.


Stumble It!

Bees know a bit of maths too

Intelligent honeybees know a bit of maths too, and can count upto four, according to an international team of scientists.

A new experiment has shown bees can discriminate between patterns containing two and three dots - without having to count the dots. And, with a bit of schooling, they can learn to tell the difference between three and four dots.

However at four, bee maths seems to run out. The team found their honeybees couldn't reliably tell the difference between four dots and five or six.

The researchers were led by Shaowu Zhang, chief investigator at The Vision Centre and Australian National University (ANU) and Hans Gross and Juergen Tautz, professors at the Wurzburg University in Germany.

The bees flew though an entry marked with a pattern of either two or three dots, which were signposts to the reward.

They then had to choose between two patterns by correctly matching the number of dots, to find where the reward was - a feat they then managed to repeat reliably once they had learned that two dots at the first entry meant they had to look for two dots at one of the second pair of patterns, where the reward was hidden.

Careful control over the experimental environment showed the bees were not using colour, smell or other clues to find their way to the hidden sugar-water reward, said Zhang, according to an ANU release.

To begin with the bees spent quite a bit of time scanning the dots. On later visits they zipped straight past them, once they knew what they meant.

The paper appeared in PLoSONE Wednesday.


Stumble It!

Pistol shrimps send out cracks of sound

One of the loudest ocean noises is created by the snapping or pistol shrimp, which inhabits tropical coastal waters. This ferocious underwater hunter, only about 2 in (50 mm) long, stalks small fish and knocks them out with stunning 'shots' of high-intensity sound. The immobilised fish tip over and the shrimp catches and eats them.

So loud is this sound that it has been known to set off sound detectors on navy submarines. In the South Pacific, fishermen are said to use the loud cracks of pistol shrimps on a reef to guide them home. The sound is made by one of the pistol shrimp's front claws, which is almost half as big again as the creature's body, although it is carried on a leg of normal size.

To produce the noise, a shrimp strikes together two parts of this enlarged claw, used both to stun prey and to defend its burrow.


Stumble It!

Sound engineers of the insect world

In his quest for a mate, the male cricket, a skilled communicator, sings three different songs: one to advertise his presence, one to court and one to ward off unwanted competitors.

First comes the calling song, a high-frequency sequence of simple chirps that is maintained for as long as it takes to attract attention. Should a female show interest by approaching, the male increases the frequency and shortens the duration of each note. This results in an excited buzz which seems to entice the female cricket.

If a male approaches, this song gives way to another, more aggressive outburst in which each chirp is drawn out in an expression of self-assertion.

Females, for their part, are well adapted to pick up these signals. They use different receptor cells in their ears and nervous systems to distinguish between the songs of competing males, and will travel right through the territory of an unwanted partner to a male that produces a more attractive song.

The male cricket produces his songs by 'stridulating' or rubbing together specially adapted areas at the base of his wings. On the underside of one wing is a row of teeth-like protrusions similar to a comb; on the edge of the other lies a tongue of toughened tissue. The tongue acts like a guitar plectrum. Each time it strikes one of the teeth it creates a sharp click. This sound is then amplified and transmitted by a resonating part of the wing called the 'harp'. The rate at which the plectrum strikes the teeth gives the songs the distinctive quality of each species.

The male grasshopper uses similar means to amplify his mating songs, but the method used to make them is different. He calls by scrapping rows of tiny pegs on his back legs against a thickened vein on the forewing. Each species of grasshopper has its own call which is determined by the arrangement of pegs and the rate at which they are scraped. The number of pegs also varies from 80 to 450 per leg.


Stumble It!

A special arm for a mating octopus

During the breeding season, a male octopus develops a modified third right arm, called a hectocotylus, Initially he may use it to caress his mate, then after a while he reaches into his body with it and pulls out a mass of spermatophores - large sperm packages shaped like baseball bats. Each has spring-like ejaculatory organ held by a cap at one end. In one octopus species, spermatophores may be more than 3 ft. (1 m) long.

Using his hectocotylus, the male pushes the sperm package into the female's body through her breathing siphon. Sometimes the arm breaks off and stays inside the female. If the male completes this manoeuvre successfully, the sperm package takes up water through a syringe-like system. The water pressure inside eventually pushes off the cap and the spring uncoils, pulling out the mass of sperm and spilling it all over her eggs.

With common squids, a female has more control. She stores the male's sperm in a cavity under her mouth until her eggs are ready for fertilisation. Then she reaches inside her own body and removes her eggs in a string. She makes sure they are fertilised by pressing them one by one against the stored package of sperm, and then she attaches them to the ocean floor in a cluster of 10-50 long strings.

In primitive insects such as the springtail, a male has to trust to luck. He leaves his sperm package on the ground hoping a receptive female will stumble across it. The moisture within her genital cavity melts the protective skin of the package, allowing the sperm to swim free and fertilise her eggs.

If a male finds another male's sperm package, he will eat and then substitute one of his own.


Stumble It!

Snakes that play the corpse for their foes

Snakes in trees often simply relax and fall to the ground out of harm's way if they are threatened, but there are snakes, such as the European grass snake and the American hognose, that are truly consummate actors. Despite the fact that a snake, dead or alive, cannot fall over a 'dying' grass or hognose snake will lie belly-up if it is threatened.

The sagging jaw, lolling tongue and deathly expression are all quite convincing, but the effect is sometimes spoiled by the wriggling involved in staying upside-down. The snake's instinctive desire to remain belly-up is so strong that it betrays itself by writhing back into its upside-down death pose if a predator tries, out of curiousity, to roll it over.

The prize for the most impressive use of props for playing dead goes to the West Indian wood snake. When threatened, this small boa twists itself into a taut coil, mimicking the stiffness of death. Fluids coating the snake's scales give off a foul stench of decomposing flesh to add to the success of the illusion.

As a final effect, blood, released from special tiny blood vessels, flushes the eyes of the coiled 'corpse' a dull red, and trickles from its gaping mouth. Thus a predator, such as a mongoose, is led to believe that the snake is dead - and that it has been so for some time.

Unless the predator is particularly hungry, or has a taste for rotting flesh, this performance is usually enough to put it off, or to make it hesitate for long enough to give the snake a chance to make its escape.

Lizards sacrifice their tails to save their lives

Lizards rely on speed and agility to flee from danger. But if running does not suffice, then the lizard brings its tail into use. Most lizard species shed their tails when they are threatened, an action that not only tends to confuse the attacker but focuses its attention on the distracting tail while the lizard makes a dash for safety. So the lizard offers its tail as a snack, albeit a fairly paltry and fleshless one, for the safety of the rest of its body. Predatory monitor lizards take full advantage of this and feed almost entirely on such discarded tails.

A lizard's detachable tail has sections that can be snapped off at will by the simple contraction of some of the lizard's muscles. In spite of the fact that the fracture occurs across the spine, the loss causes the creature little discomfort. This is because the joints at the 'crisis point' where the tail breaks off are made of cartilage rather than bone, and blood vessels and nerves are constricted to reduce the pain and blood loss.

Although a lizard's tail is not essential, it does play an important role in balance and in breeding success. The lost tail grows again with time, although it may differ in length or pattern from the original, and the lizard may even end up with more than one tail. Victorian records, for example, tell of a lizard which had seven. But regrowing a tail takes considerable energy. If a predator refuses to eat the snack, some skinks have been known to return to eat their own discarded tails.

The glass snake is really a lizard with no legs. It takes its name from its extraordinary ability to shatter its own body. If under stress, this 5 ft (1.5 m) long creature fractures its tail at all or most of its joints. Each piece then wriggles around on its own, while the snake itself slips away - sometimes reduced to two-thirds of its original length.

A species of gecko found in Puerto Rico also dismantles itself spectacularly when in danger. It sheds bits of skin from all over its body, or even its whole outer covering, and moves off to safety.

Matching the wardrobe to the season

From the tiger's stripes, which echo the light and shade of the forest, to the bright green of the tree frog, most animals have developed color schemes that blend with their environment. In situations where that environment is subjected to extremes of seasonal change, however, extra and rather special adaptations are called for.

Like other birds living in landscapes that are snow covered for part of the year, the Scandinavian willow grouse regularly exchanges the tones and patterns of its brown summer plumage for winter whites. Not that the transition is abrupt; rather it is gradual, mirroring the drift of summer into autumn and then into winter. The willow grouse's life is constantly under threat . Terrestrial predators such as lynxes and wildcats share its mountain and tundra home, and eagles sheel overhead. Survival depends upon the grouse making the most of its colouring by gearing its movements to the state of its surroundings. Thus its greatest security is achieved when there is a good blanketing of snow and the bird is in full white feather.

During the long spring thaw, the landscape becomes a patchwork of snow, rock and exposed vegetation. While the grouse retains its winter colours, it will feed only against a snowy background. Not until its plumage is almost completely changed again will the bird move to snowless terrain. So important is the right camouflage to the grouse that it will even cut down its food intake rather than risk exposing itself against a contrasting background.

Birds that know when to hide their beauty

For a great deal of the year the golden plover struts conspicuously among the dune grasses and heathers of its moorland breeding ground. It has striking black and white plumage on the front, and a broken, spangled pattern on a golden-brown back. But when the time comes to incubate its eggs, it cannot afford to draw attention to itself. It is then that the plumage on a female's back shows its value as camouflage.

As the hen crouches low on the nest, her back blends in with the surrounding carpet of windblown, flower-speckled grass. She is practically invisible from above and from the sides. Thus her eggs are able to hatch in safety.

A relative of the golden plover, the eye-catching blacksmith plover of tree-scattered African grassland, is so conspicuous in its black and white feathers that it would be futile for it to attempt to blend with its background. Its nesting technique, though, is of startling originality - it often lays its dark, mottled eggs in a pile of zebra dung, which is probably the last place any hungry predator would think of looking for a meal.

Another relative is the ringed plover - a wader that breeds on rocky coasts. Rejecting formal nest building, it lays its mottled eggs straight onto the shingle, from which they are indistinguishable. The adult is similarly camouflaged, with sandy wings and black and white head. The downy chicks are equally difficult to see against the pebbles and debris of the shore.

It takes a very good disguise to enalbe a bird to sleep safely on the ground by day. The white-throated nightjar hunts moths at night; but at daylight, it selects a spot among the dried vegetation, where it is practically invisible. It is probably more at risk there from being trodden on than from being attacked by a predator.

Wings that are meant for one flight only

It happens only once during the termite year. On one warm, still summer evening, breaches appear in the towering earthen mound of an African termite nest. From the holes, fluttering a little inexpertly on gauzy wings, emerge hundreds, or sometimes thousands, of plump termites. The swarm consists of both males and females of the royal, or reproductive, caste - the only termites to grow wings. Their flight is of short duration. Though they climb some 200 ft (60 m) into the air, they travel no more than 300 yd (275 m) from their home mound. Like paratroops ridding themselves of their 'chutes, as soon as they land they termites pivot on their wings and break them off, for they are no longer needed. Both sexes search excitedly for a mate, then run off in tandem, the males hard on the females' heels. At this point they are in extreme danger, for even creatures that would not normally eat termites - spiders, shrews, lizards, birds, even local tribesmen - close in on this insect feast. Very few of the couples survive, but those that do seek a nest site in the ground or in a decaying log, and burrow in, excavating a mating chamber. It is lined with chewed wood mixed with saliva and droppings, and once it is complete, they seal themselves in.

From now on the queen, with her consort beside her, will do nothing but lay eggs, creating a colony that over years may amount to millions. Most of her offspring will become workers, sterile males and females. They forage for food - plant and wood fibres - and build and repair the nest mount, which may eventually reach a height of 30 ft (9 m).

Their taks include feeding and grooming the royal pair, as well as the soldier caste that guards the nest.

Fish Poop Helps Balance Ocean Acidity

The ocean's delicate acid balance may be getting help from an unexpected source, fish poop.

The increase in carbon dioxide in the atmosphere not only drives global warming, but also raises the amount of CO2 dissolved in ocean water, tending to make it more acid, potentially a threat to sea life.

Alkaline chemicals like calcium carbonate can help balance this acid. Scientists had thought the main source for this balancing chemical was the shells of marine plankton, but they were puzzled by the higher-than-expected amounts of carbonate in the top levels of the water.

Now researchers led by Rod W. Wilson of the University of Exeter in England report in the journal Science that marine fish contribute between 3 percent and 15 percent of total carbonate.

And the contribution may be even higher than that, say the researchers from the U.S., Canada and England.

They report that bony fish, a group that includes 90 percent of marine species, produce carbonate to dispose of the excess calcium they ingest in seawater. This forms into calcium carbonate crystals in the gut and the fish then simply excrete these "gut rocks."

The process is separate from digestion and production of feces, according to the researchers.

The team estimated the total mass of bony fish in the ocean at between 812 million tons and 2,050 million tons, which they said could produce around 110 million tons of calcium carbonate per year.

The carbonate produced by fish is soluble and dissolves in the upper sea water, while that from the plankton sinks to the bottom, the team noted.

The research was funded by the U.K. Biotechnology and Biological Sciences Research Council, The Royal Society, the U.S. National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, United Nations Environmental Program, the Pew Charitable Trust and the U.K. Department of Environment, Food and Rural Affairs.

Protests or not, Japan keeps eating whale

Japanese businessmen enjoy their whale meat lunches at a whale meat eatery in Tokyo in this photo taken on May 5, 2007. As diners sit down to their whale meat lunches in Tokyo and elsewhere across the nation, its whaling fleet is now on its annual hunt in the Antarctic keeping specialty restaurants alive but drawing blunt public criticism from neighboring governments, protests from environmental groups and the ire of whale-lovers worldwide. ((AP Photo/Katsumi Kasahara))

As diners sit down to lunches of whale meat in Tokyo and elsewhere across the nation, Japan's whaling fleet is on its annual hunt in the Antarctic, drawing protests from environmental groups, international governments and whale-lovers worldwide. So why does Tokyo persist?

Why shouldn't it, many Japanese say.

"Why do people say we can't eat the things we've eaten since the end of World War II?" asked Koji Shingu, the proprietor of a whale eatery called Yushin in Tokyo, a few blocks from the city's oldest temple, a popular tourist draw.

His feelings echo those of many older Japanese.

The country has hunted whales for hundreds of years, and the meat is a sentimental favorite of people who lived through the lean postwar years, when whale was the chief source of protein because Japan couldn't afford pork or beef. Whale was a common family dish, and many schoolchildren ate it every day.

Whale meat is still easily found in restaurants and canned in supermarkets, but is not a part of a typical home-cooked meal.

Shingu says most of his customers are in their 40s or older, while younger diners come mainly for the novelty. At the tail end of lunch hour, his clients included several older men eating alone and a pair of younger girls at a corner table.

The calm in the restaurant belied the battle it took to bring in the whale meat it serves.

The Japanese fleet, now somewhere between New Zealand and Chile, catches mostly minke whales, which at about 25 feet (7.6 meters) long and 5 tons are smaller than many other species.

It's dangerous work—the current expedition has lost a crew member, who fell overboard and is presumed dead.

The task is made more difficult by environmentalists who relentlessly pursue the hunters.

This year the conservationist group Sea Shepherd has chased Japan's whaling ships for thousands of miles and thrown bottles of rancid butter to disrupt operations. In late December the group's ship and a whaling boat collided at sea.

Commercial whaling is banned internationally, but the six-vessel Japanese fleet operates under permission from the International Whaling Commission, which allows hunting for research purposes. Japan plans to take up to 935 minke whales and 50 fin whales this year, and says it sells most of the meat for food only after conducting its research.

Minke whales are not endangered, and few dispute that there are hundreds of thousands in the wild. But many feel that Tokyo's research operation is thinly veiled commercial hunting, and that harpooning whales at sea is a brutal way to kill them.

"We deal with a ruthless and cruel enemy whose very reason for being here is to inflict agonizing suffering and to deliver cruel death to gentle, sensitive, intelligent and socially complex sentient beings," the founder of Sea Shepherd and captain of its ship, Paul Watson, wrote from the Antarctic last week after clashing with whalers.

Makoto Ito, the managing director of Kyodo Senpaku, the company that runs Japan's whaling fleet, says invoking images of whales being killed at sea is unfair because killing animals for food is never a pretty sight.

"There are intense scenes of cows and chickens being slaughtered too," he said.

Ito says the scientific whaling done by his company, in connection with the government-backed Cetacean Research Institute, is needed to prove there are enough minke whales for harvesting, and thus for the lifting of the commercial whaling ban.

He said the entire operation costs $65 million to $76 million per year, of which the government provides about $5.5 million. The rest comes from selling the whale meat, and the entire operation is "barely making a profit."

But international allegations that it is commercial whaling in disguise abound, and Japan has been strongly criticized by a number of nations, including Australia and New Zealand, as well as the United States.

This week, Tokyo said Sea Shepherd's activities are tantamount to terrorism and said it planned to ask Australia to bar the group's anti-whaling ship from its ports.

Australia, which has been a leading opponent of whaling, said it wouldn't do so.

Sea Shepherd's aggressive save-the-whales campaign has resonated with Western audiences and is the subject of a popular series on the Animal Planet TV network, "Whale Wars," filmed from its ship.

Images of foreigners interfering with what is seen as a traditional fishing tradition have helped stir up pro-whaling sentiment in Japan. Still, younger generations are increasingly fond of red meat and other Western food, and without a publicity boost, whaling may fade away on its own.

That, Ito said, would be a shame.

"If there are plentiful resources, and we can take some without causing whales to go extinct for future generations, what is wrong with that?" Ito asked.

Ants Practice Nepotism, Study Finds

The highly social and complex world of ants is not void of selfish acts. Worker ants of the species Formica fusca apparently can distinguish who their closest relatives are and kill their more distant relations.

"That workers capitalize on this ability simply means that the workers use the information they have to enhance their genetic contribution to future generations," said Liselotte Sundström, an entomologist at the University of Helsinki in Finland.

Science has long held that ants who share the same genetic make up have a vested interest in favoring their closest kin at the expense of the social cohesion of the entire ant colony. But evidence for ant nepotism has been difficult to find.

Sundström and colleague Minttumaaria Hannonen took advantage of advances in genetic analysis to prove the theory correct. They report the results of their study in the February 27 issue of Nature.

Kenneth Ross, an entomologist at the University of Georgia in Athens, said that researchers have looked for nepotism in social insects for the last 10 to 15 years and not found it. Given that fact, Ross said he was surprised at the success of Sundström and Hannonen's study, which he described as nicely done.

"The theory tells us it should be there," he said. "But the implication from data from the last 10 to 15 years tells us it shouldn't be there. In light of these negative results, I am somewhat surprised."

Ant Study

Unlike bee colonies, ant colonies are often ruled by more than one queen. Among some species, such as fire ants, a single ant colony can have as many as 500 queens. On the surface, the ants in such colonies seem to work cooperatively for the interest of the entire group.

Scientists have often wondered if evidence for nepotism is present in such a complex social environment. But each time they have looked for it their results come up negative. Sundström said that perhaps their studies were hindered by logistical constraints.

"For instance, there has not been any way to very accurately distinguish the brood produced by different queens, especially in the field where the actual number of queens is not known," she said.

In addition, Sundström said scientists have not had a way to accurately determine how closely individuals within a colony are related to each other. As a result, they could not predict which ants should favor others if nepotism were indeed taking place.

But advances in genetic analysis enabled Sundström and Hannonen to test for nepotism. The pair were able to distinguish one ant's DNA from another's and use certain genetic markers to determine what queen was the mother of various ant offspring.

They conducted their experiment on laboratory colonies with two mother queens. The colonies were set up in the early spring, just before the queens lay their brood. At the time the colonies were established, they consisted of only the queens and adult worker ants.

"When the queens started to lay eggs in our laboratory colonies, we collected a sample of about 50 eggs and left about the same amount in the colony. The eggs left in the colony were allowed to mature into adults," said Sundström.

The researchers then screened all the queens and eggs and a sample of mature individuals from each colony. Based on their genetic analysis, the researchers determined the proportion of eggs laid by each queen and also the proportion of the adult brood that belonged to each queen. The researchers then calculated how the proportions had changed.

"We predicted that if the workers on average are more closely related to one queen than the other they could gain genetic benefits by favoring the offspring laid by this queen," said Sundström. "Conversely, if the workers are equally related to both queens they would have no incentive to favor the offspring of one queen over the other."

If the researcher's theory is correct, in colonies where there is a high proportion of worker ants more closely related to one queen than the other, the brood belonging to the queen with all the close working relatives will get a higher proportion of surviving offspring.

The results from Sundström and Hannonen's experiment were in line with this prediction, implying that "the workers manipulated brood composition to fit their interests," said Sundström.

Ross says there is little reason to question the methodology of Sundström and Hannonen, but their result does raise the question of why nepotism was found in this species of ant when it has not been found in so many others.

"You can't argue that the earlier studies were systematically flawed, so why is this one different?" he said.

Nepotistic Behavior

While the researchers do not yet have direct evidence that workers remove eggs or larvae to achieve their nepotistic goals, they say that such action is the most plausible explanation for the observed nepotistic behavior among Formica fusca ants.

"The rationale behind this argument builds on kin selection theory," said Sundström. "In social insects such as ants and bees, workers are sterile females, which help their mother, or some other female relative to reproduce."

Since the workers share half their genes with their mothers, they also share half their genes in common with their siblings. Since siblings have more genes in common than do cousins, if a worker wants to see its genes passed on to the next generation, it's to the ant's advantage to favor its close relatives, assuming it can tell which ants are its closest relatives.

"Accurate kin discrimination abilities are a prerequisite for nepotism. Because we found evidence for nepotism, we can conclude that workers have the necessary ability to discriminate between closer and more distant relatives," said Sundström

That nepotism is now known to exist at least among one species of ant in one situation, Ross says it puts ant nepotism research back 15 years, posing such questions as, "How common is it? How universal is it? What sort of conditions should we expect to see it in?" he said.

Sundström finds such questions to be the most rewarding aspect of her research. "Every time one resolves one question, there will be ten new ones emerging."

Dinosaur Dads Took Care of Nest

The movie Jurassic Park gave advanced, birdlike dinosaurs a fearsome reputation--swift, intelligent, and deadly. Now it turns out that they had a softer side. Researchers report that males in three species were stay-at-home dads that incubated the eggs in their nests.

There's plenty of evidence to suggest that dinos baby-sat their offspring. A predatory dinosaur called Oviraptor, for example, was discovered in the Gobi Desert in 1993, its fossilized remains protecting a brood of eggs. In addition, dinosaurs' closest living relatives, birds and crocodiles, display nesting behavior: Female crocs guard the eggs, whereas in birds the gender of the stay-at-home-parent depends on the species. But whether male or female dinos had nest duty has remained a mystery.

For the new research, paleontologist David Varricchio of Montana State University in Bozeman compared three species of birdlike dinosaurs--Oviraptor, Citipati, and Troodon--with birds and crocodiles. All three types of dinosaurs were found on nests, and those nests contain large clutches of eggs, as many as 30 each. Varricchio and his colleagues investigated whether they could discern the nesting behavior from the relationship of the clutch size and the animal's body size. Measurements in 433 living birds and crocodiles revealed that, for a given body size, species in which males took care of the nest tended to have the largest clutches. The next-largest clutches were cared for by mothers. Mom-dad partnerships had the smallest clutches. Extrapolated to dinosaurs, the data revealed a pattern of paternal care in the ancient beasts.

Another line of evidence in the paper comes from Gregory Erickson, a biologist at Florida State University in Tallahassee. His studies of dinosaur bone tissue showed that none of the seven specimens associated with nests showed signs of changes associated with egg laying, such as medullary tissue (ScienceNOW, 2 June 2005). That's not sure-fire proof the nest-caretakers were male, he notes, but it's consistent with the hypothesis. The findings are reported in tomorrow's issue of Science.

Richard Prum, an ornithologist at Yale University, says he never expected paternal care in dinosaurs. But with their dinosaur ancestors showing more and more traits once thought to be exclusive to birds, such as feathers, he says the finding makes sense. It also points to a question on the reproductive frontier: Did dinosaurs practice polygamy?

Santa Likely Pulled by All-Female Reindeer Team

There may be a perfectly good reason why Santa doesn't get lost on his annual Christmas globetrot: His flying reindeer just might be female and don't mind stopping for directions.

The gender of Rudolph and his or her sleigh-hauling friends -- the subject of goofy Internet chatter every year around this time -- is now being pondered by renowned wildlife experts at Texas A & M University.

"Santa's reindeers were really females, most likely," said Alice Blue-McLendon, a veterinary medicine professor specializing in deer who cites the depictions of Santa's helpers with antlers as the primary evidence. It turns out reindeer grow antlers regardless of gender, and most bulls typically shed their fuzzy protrusions before Christmas.

But Santa's sleigh helpers might also be castrated males, known as steers, said Greg Finstad, who manages the Reindeer Research Program at the University of Alaska Fairbanks.

Young steers finish shedding their antlers in February and March, just as non-expecting females do. Bulls generally lose theirs before Christmas, while expectant mothers retain their antlers until calves are birthed in the spring. This allows them to protect food resources through harsh weather and to have enough for developing fetuses, he said.

Sledders most often use steers because they maintain their body condition throughout the winter, he said. Bulls are tuckered out from rutting season when they mate with as many as a dozen females in the months leading up to December. That leaves them depleted and too lean to pull a sleigh or sled through heavy snows, Finstad said. Many females are pregnant after rutting season, which lasts from summer and into the fall. That would mean long hours of backbreaking work for an expecting Rudolph, as well as Donner, Blitzen, Cupid, Dasher, Dancer, Prancer, Comet and Vixen. "You don't hook up your pregnant females to a sled," Finstad said. "That is not good animal husbandry."

But other aspects of the Christmas story support the all-girl sleigh team theory, Blue-McLendon said.

For example, would a boy reindeer really sport a shiny red nose that almost glows?

"Females like accessories," said Blue-McLendon, who in 2003 led the school's cloning of a white-tailed deer. "I think that fits because females like bling. We like shiny stuff."

As for the reindeer games, forget the rough antler-smashing stuff. Blue-McLendon suggests a female Rudolph would be more up for "games of wit."

And as for the name, Rudolph could certainly still work.

"Why not?" Blue-McLendon said. "I know women named Charlie."

110 tigers lost in six years in India

India's forests have lost at least 110 royal striped cats, including 17 tigresses, in the past six years due to poaching and several other reasons, according to government data.

The figures made available under the RTI Act reflects that the royal predators have been unsafe not only in non-protected area but also inside reserves, given that this year alone 14 cases of tiger mortality, including four tigresses and two cubs, have been reported till November.

Of six cases of poaching, three tigers were killed in the last month itself with one each outside
Kanha and Khatiya buffer range in Madhya Pradesh and another in Dudhwa tiger reserve in Uttar Pradesh, according to the data.

Similarly, as many as 30 endangered big cats died in 2007, highest in the past five years, with 16 perishing in reserves while 14 in non-protected areas.

Five big cats died in world famous Corbett Tiger reserve in Uttar Pradesh while Bandipur park in Madhya Pradesh lost two tigresses.

During the same period, 14 cases of tiger mortality were reported from outside reserves of which five of the big cats were killed in poaching and three due to poisoning.

A man-eater tiger which had strayed in Chandrapur in Maharashtra's Nagpur region had to be shot dead by the forest department late last year.

“These are official figures and the actual figures may be higher,” Delinda Wright, prominent wildlife expert, noted.

The situation was grim in 2006 too when eight tigresses and two male striped cats died inside the reserves in various tiger-range states.

One-horned Deer

A deer with a single horn in the center of its head — much like the fabled, mythical unicorn — has been spotted in a nature preserve in Italy, park officials said Wednesday.

"This is fantasy becoming reality," Gilberto Tozzi, director of the Center of Natural Sciences in Prato, told The Associated Press. "The unicorn has always been a mythological animal."

The 1-year-old Roe Deer — nicknamed "Unicorn" — was born in captivity in the research center's park in the Tuscan town of Prato, near Florence, Tozzi said.

He is believed to have been born with a genetic flaw; his twin has two horns.
Calling it the first time he has seen such a case, Tozzi said such anomalies among deer may have inspired the myth of the unicorn.

The unicorn, a horse-like creature with magical healing powers, has appeared in legends and stories throughout history, from ancient and medieval texts to the adventures of Harry Potter.
"This shows that even in past times, there could have been animals with this anomaly," he said by telephone. "It's not like they dreamed it up."

Single-horned deer are rare but not unheard of — but even more unusual is the central positioning of the horn, experts said.

"Generally, the horn is on one side (of the head) rather than being at the center. This looks like a complex case," said Fulvio Fraticelli, scientific director of Rome's zoo. He said the position of the horn could also be the result of a trauma early in the animal's life.

Other mammals are believed to contribute to the myth of the unicorn, including the narwhal, a whale with a long, spiraling tusk.

Cat puts Japan rail firm on track

A loss-making Japanese railway company is back on track thanks to the popularity of a stray cat.

Wearing a black cap and posing for photos with passengers, Tama the tabby is credited with boosting Wakayama Electric Railway's revenue by 10%.

The firm had to axe all staff at Kishi station in western Japan two years ago.

But Tama stuck by her post and was rewarded with promotion to station manager. The pet mascot even has her own office, a former ticket booth.

The feline, who was born and raised at the station in the city of Kinokawa, Wakayama prefecture, is living proof of the Japanese belief that cats are good luck.

"She never complains, even though passengers touch her all over the place. She is an amazing cat. She has patience and charisma. She is the perfect station master," said Yoshiko Yamaki, a spokeswoman for the rail company.

The nine-year-old - who receives cat food in lieu of a salary - won national stardom last year when the firm formally appointed her as "station master".

Since then passengers have been gradually returning, recently rising 10% to about 2.1 million a year.

The cat has spawned a range of popular merchandise, including a picture book called: "Diary of Tama, the Station Master."

Source : BBC