BEES PLEASE!

[The Hemispheres Kid]

These fuzzy flying insects are not just fascinating, they are also extremely important for the job they do – do you know what it is?

Pollination! It’s a bee’s job. Flowers make a powder called pollen. When pollen is carried from a flower on one plant to a flower on another plant, the result is called cross-pollination. That’s how flowering plants reproduce. The 20,000 species of bees in the world are the champion pollinators in the insect world.

How do bees carry pollen from one flower to the next? Most bees have spiky or feathery body or leg hairs that collect the pollen as the bee moves around inside the flower – rather like Velcro collecting lint! It’s the female bees who do the work. Male bees don’t collect pollen; they just eat it. When the bee moves to the next flower, some of the pollen dust falls off. If it lands on the right part of the flower – presto, pollination!

But bees don’t move all this pollen around because they’re crazy about flowers. Bees depend on pollen from flowers for their protein and on flower nectar and oils for their energy. Female bees gather pollen to feed their young, called larvae. It’s as if bees were flower farmers, carefully tending their flower gardens in order to raise their food.

Besides buzzing, making honey and stinging, bees are famous for living in complex groups, called colonies. However, did you know that some species of bees, called solitary bees, live alone? In fact, 85% of the bee species in the world are solitary bees!

The life of a solitary bee really is a lonely one. Here’s how it goes: the male and female solitary bees mate in the spring. The female then builds a nest by herself. The nest is made up of individual cells, about 10 in most cases, into each of which the female puts a blob of pollen and nectar. She lays an egg on the blob and then seals the cell. Once she has all her eggs properly stowed away, she leaves. And that’s it! She never returns to see her offspring.

But she has taken care to see that her babies will have enough to eat. When the eggs hatch, the larvae (newborn bees) have the pollen and nectar to feed on. Eventually, they pupate (turn into adult bees) and fly away to begin their own solitary lives.

Despite their name, some solitary bees like to hang out near other solitary bees, so they build their nests close to each other. It’s like a condominium, where each bee has her own private flat but can see her neighbors if she wants to – it’s called a nesting aggregation.

Of course, it’s the other 15% of bees – the honeybees and bumblebees – who have the famous lifestyle! They live in colonies and their social structure is complex and strict. A typical small hive (the nest the bee colony lives in) may have 20,000 bees, so they need a system for living together!

Most of the 20,000-200,000 bees in a hive are worker bees. These are small female bees whose job is to do – everything! They make the cells, gather the nectar and pollen, tend the larvae, clean and defend the hive, and take care of the one and only queen bee. It’s no wonder their life is so short: a mere 20-40 days in the summertime.

The queen bee, who is much larger than the workers, has only one job, but it’s a full-time one. She lays eggs, without a break. After every 20 eggs, some of the workers give her a small meal. She doesn’t leave the hive and has no ability to gather pollen or nectar. Once she can no longer do her job – after a life of about two years – the workers move one of her eggs into a special cell designed only for producing a queen. When the new queen hatches, she destroys any other queen eggs and kills any other hatched queens – she may even do away with her mother!

The third kind of bee that may be in the hive is the drone. Drones are medium-sized males, whose only job is to mate with the queen. They have no stinger and cannot gather food, so when they are no longer needed, they are driven out of the hive to starve to death. The poor drone is unlikely to live long anyway; once he mates with the queen, he dies.

It’s a tough society, but a useful one. The partnership between bees and plants is also good for humans. We don’t just need bees for flowers and honey – we need them to pollinate our fruits and other seed crops! Without proper pollination, a watermelon wouldn’t be sweet. Tomatoes, peppers, beans, peas, corn, squash, cucumbers, clover, sunflowers…none of them would be any good without the diligent pollination provided by bees. So the next time you see a bee at work, you might want to say thank you, bee!

Bee’s-eye view

Did you know that bees have two compound eyes, made up of thousands of six-sided facets, and three simple eyes? They can see amazingly well – but only up to about one metre in sharp detail! They can even see ultraviolet light, which we can’t. That means that even when it’s cloudy, bees can see where they’re going. (If you want to see how scientists think the world looks to a bee, check out the B-Eye web site at http://cvs.anu.edu.au/andy/beye/beyehome.html).

Now, that’s team spirit!

When a honeybee finds a juicy patch of flowers full of nectar, does she hog it all to herself? She does not! She does a dance that tells the other bees in her hive where to find the feast. She uses the position of the sun to figure out the path they should fly to get there.

A little bee history

Bees evolved from wasp-like insects about 40 million years ago. It took about 10 million years for some bees to develop the kind of social structure honeybees are famous for now. The solitary bees still resemble their primitive wasp relatives more than the honeybees and bumblebees do.

A queen is born

How does an ordinary honeybee larva become a queen? The secret is in how the larva is treated. First of all, the queen-making cell is larger than the ordinary cells, so the larva has more room to grow. She is also fed something called “royal jelly,” which is a mixture of pollen, honey and special fluids from the worker bees. (Honey is made from flower nectar. Once the nectar is stored in the hive, worker bees fan it with their wings, to evaporate the water from it. What’s left is honey.)

ANEMONE MINE: The Amazing Partnership between Sea Anemones and Anemonefishes

[The Hemispheres]

You wouldn’t think that a primitive, boneless, animated tube would be anybody’s pick for a best friend, but that’s exactly what the sea anemone is to the anemonefish. Scientists have only recently begun to understand the fascinating relationship between anemonefishes and their invertebrate hosts.

Sea anemones are marine invertebrates of varied and often beautiful appearance, not unlike the flower from which they take the Greek part of their name: the anemone, or “daughter of the wind.” The nearly 1,000 species of sea anemone are members of the phylum Cnidaria (sometimes called Coelenterata instead). Cnidaria refers to the cnidae, or nematocysts – the stinging cells that are unique to this phylum.

Sea anemones belong to the class Anthozoa, which also includes the corals. Unlike the colony-building corals, however, sea anemones are often solitary dwellers, living anchored to a hard surface, such as a rock, or imbedded in the ocean floor. They are generally tube-shaped (a form called a polyp), with a single opening at one end. The pedal, or “foot,” end of the body is either pointed, for digging into sediments, or disk-shaped, for attaching to something firm. The disk oral end bears the mouth opening, through which all water, food and gametes pass. The mouth is surrounded by nematocyst-bearing tentacles, with which the anemone captures food and defends itself. The internal cavity of the sea anemone, which serves as stomach, lungs, intestines, circulatory system, etc., is laced with vertical partitions called mesenteries.

Anemones can grow up to a metre in width and live up to 100 years. Their reproductive methods are varied and not entirely understood. Although all anemones are sexed – male or female – and can release eggs or sperm into the water, depending on their gender, they can also reproduce by splitting off a piece of their pedal disk, or even dividing in half. In the case of reproduction from eggs, some anemones incubate them inside their body cavity until fully formed baby anemones emerge. The young swim until they find a likely spot to attach themselves to.

Ten species of sea anemone have evolved a symbiotic relationship with the 28 species of fish collectively known as anemonefishes. Twenty-seven of the anemonefish species belong to the genus Amphiprion, while the remaining one is the only recognized species of the genus Premnas. Anemonefishes are popular in aquariums because of their bright colors, often striped patterns and bobbing motion in the water, all of which gave rise to their commercial name of clownfish.

Although sea anemones are found everywhere – from the equator to the poles – the ten species of host anemone, as they are known, live only in the tropical latitudes of the Indian and Pacific Oceans and in current-warmed areas such as the east coast of Japan. Interestingly, the host anemone species are not closely related to one another. They come from three different families, the Actiniidae, Stichodactylidae and Thalassianthidae, none of which are made of exclusively of symbiotic species. Actiniidae is the largest sea anemone family, containing most of the common shore species. The Strichodactylidae family is found only in the tropics and includes most of the host anemones. Thalassianthidae is also tropical.

Anemones and anemonefishes live in coral reefs, sand-flats near reefs and even at distances from reefs. They are found only to depths of 50 m – coincidentally convenient for divers and scientists – because the algae that live in the anemone’s tentacles and oral disc need sunlight for photosynthesis. The surplus energy generated by these microscopic, single-celled zooxanthellae fuels the anemone, making it worth the invertebrate’s while to stay in shallow, clear waters.

The first published account of the symbiotic relationship between sea anemones and anemonefish appeared in 1868, in Rambles of a Naturalist on the Shores and Waters of the China Sea by Dr. Cuthbert Collingwood, who made his observations off the coasts of Borneo. Since then, the details of this remarkable living arrangement have slowly come to light. With their stinging nematocysts, the sea anemones would seem to be a forbidding choice for a home. The nematocysts are microscopic capsules found inside the cells of the anemone’s tentacles and body. Each capsule contains a length of tube that shoots out, when the necessary stimuli are given, to sting the stimulatory object. Some types of nematocyst contain toxins. In the face of such weaponry, how and why do the anemonefishes choose to make the sea anemone their home?

The why would seem to be for protection, as well as to feed on scraps of food from the anemone’s meals. The anemonefish shelters in the sea anemone’s stinging tentacles, limiting its territory pretty much to the immediate vicinity of its host. How it is able to do so with impunity has elicited a variety of theories from biologists. Some of the ideas that have turned out to be false include that some anemones do not have nematocysts; that anemonefishes have unusually thick skin; that the fishes never touch the tentacles; and that the anemone does not use its stingers while the fish is within its tentacles. In fact, it would appear that there is something about the mucus coating of anemonefishes that differs from the mucus coating of other fishes and protects them from stings.

Which, of course, leads to the question of what that difference is? There are two main hypotheses among scientists: one, that the fish have evolved a mucus coating that does not contain substances that would stimulate the nematocysts to sting, and the other, that the fish pursues a “courtship” of the anemone that involves enduring some initial stinging, until the fish is coated with the anemone’s own mucus, which camouflages it and allows it to move freely in and around its host. This would explain why anemonefishes tend to return to the shelter of the host’s tentacles about once per minute; in this scenario, they are renewing their protective coating.

Separations of fish and host have been observed in captivity. If the separation is prolonged, the fish will be stung when it tries to reunite with its host. In such cases, the fish re-courts the anemone, letting the tentacles first touch its fins and then its belly, before moving back in. The performance is ritualized and unvarying.

There may be no single correct answer to the mechanism by which anemonefishes are able to live with anemones. Some anemonefish species are host-specific, whereas others can dwell with many species of anemones. Some anemones play host to more than one anemonefish at a time, while others will drive away all but a single resident fish. With so many variables at work, it seems likely that the entire spectrum of explanations, from adaptation to behavior, comes into play, in varying degrees.

The next question, of course, is why sea anemones have evolved as hosts to anemonefishes. What advantage is it to harbour flashy fishes in one’s tentacles? First of all, the fish keep the anemone clean, ridding it of food scraps and parasites. Secondly, the fish chase away butterfly fish (which are immune to the anemone’s sting) and other predators that feed on anemone, such as turtles, starfish and nudibranches.

Some species of anemonefish live in mated pairs in one anemone, while others live in larger groups. There is a strict social structure, presumably evolved to ensure survival. At the top of the group is a large, dominant female, who mates only with the large males. She lays her eggs inside or close to the anemone, searching out and bringing in a suitable surface for laying her eggs, if necessary. Anemonefishes can change gender, when circumstances require it. When the top female dies, the largest male in the group will shift to female and take over her role. The advantage is obvious: since anemonefish cannot live for long away from the shelter of the anemone, leaving home to seek new mates is too risky. However, it has been observed that the member of a single group are not all related, which means that baby anemonefishes do travel from their birth site and find a home in a new anemone.

Anemonefishes are not the only sea creatures to take advantage of the sea anemone’s stinging power. Crabs, shrimps and other fishes, including young damselfish, may live in or with anemones. In one of the more interesting adaptations to have evolved, the boxer crab (Lybia tessellata) dons anemones like boxing gloves and uses them to beat away predators. However, no other group of species has so thoroughly united itself with the primitive but powerful sea anemone as the anemonefishes have.

The Ten Species of Host Anemone and their Anemonefish Species:

Cryptodendrum adhaesivum Adhesive Sea Anemone
Fish: A. clarkii

A very colorful species, with short, dense extremely sticky tentacles, often brightly and variously colored in combinations of green, fuchsia, pink, blue, etc. Found in Australia, southern Japan and Polynesia, Micronesia and Melanesia to Thailand, the Maldives, and the Red Sea.

Entacmaea quadricolor Bulb-Tentacle Sea Anemone
Fish: A. akindynos, A. allardi, A. bicinctus, A. chrysopterus, A. clarkii, A. ephippium, A. frenatus, A. mccullochi, A. melanopus, A. omanensis, A. rubrocinctus, A. tricinctus, Premnas.

The most widespread of the host anemones, this species is unique for the bulbs it often has on the ends of its tentacles. It may live as an isolated polyp or in a cluster with other polyps, especially in shallow water. It is found from Micronesia and Melanesia to South Africa and the Red Sea and from Australia to Japan.

Hecteractis aurora Beaded Sea Anemone
Fish: A. akindynos, A. allardi, A. bicinctus, A. chrysogaster, A. chrysopterus, A. clarkii, A. tricinctus.

This species takes its name from the lumps or swellings strung along its tentacles. It can burrow completely into sea sediment if its foot is attached to a solid surface below. Found from Micronesia and Melanesia to East Africa and the Red Sea, and Australia to the Ryukyu Islands of Japan.

Heteractis crispa Leathery Sea Anemone
Fish: A. akindynos, A. bicinctus, A. chrysopterus, A. clarkii, A. ephippium, A. latezonatus, A. leucokranos, A. melanopus, A. omanensis, A. percula, A. perideraion, A. polymnus, A. sandaracinos, A. tricinctus.

This species is distinguished by the quantity of its tentacles – up to 800 – which shrivel and turn green or grey when the anemone is disturbed. Found from French Polynesia, Micronesia, and Melanesia to the Red Sea, and Australia to Japan.

Heteractis magnifica Magnificent Sea Anemone
Fish: A. akallopisos, A. akindynos, A. bicinctus, A. chrysogaster, A. chrysopterus, A. clarkii, A. leucokranos, A. melanopus, A. nigripes, A. ocellaris, A. percula, A. perideraion.

A large, robust animal, well-known through photographs, thanks to its preference for exposed perches and its dazzling colors – including blue, green, red, white and brown. Found from French Polynesia to East Africa, and Australia to the Ryukyu Islands of Japan.

Heteractis malu Delicate Sea Anemone
Fish: A. clarkii

Characterized by sparse, short, usually magenta-tipped tentacles. Capable of retracting its entire, slender column into sediment. Found from the Hawaiian Islands to Australia and Japan.

Macrodactyla doreensis Corkscrew Tentacle Sea Anemone
Fish: A. chrysogaster, A. clarkii, A. perideraion.

This species has sparse, long tapered tentacles that often assume a corkscrew shape. Found from Japan to New Guinea and northern Australia.

Stichodactyla gigantea Gigantic Sea Anemone
Fish: A. akindynos, A. bicinctus, A. clarkii, A. ocellaris, A. percula, A. perideraion, A. rubrocinctus.

This species has a deeply folded oral disc and short, sticky tentacles that tend to vibrate constantly. Found from Micronesia to the Red Sea, and Australia to the Ryukyu Islands of Japan.

Stichodactyla Haddoni Haddon's Sea Anemone
Fish: A. akindynos, A. chrysogaster, A. chrysopterus, A. clarkii, A. polymnus, A. seba.

This species lives burrowed in sediment, with its oral disc just at the surface, and can disappear completely beneath the sand when alarmed. Found from the Fiji Islands to Mauritius, and Australia to the Ryukyu Islands of Japan.

Stichodactyla Mertensii Mertens' Sea Anemone
Fish: A. akallopisos, A. akindynos, A. allardi, A. chrysogaster, A. chrysopterus, A. clarkii, A. fuscocaudatus, A. latifasciatus, A. leucokranos, A. ocellaris, A. sandaracinos, A. tricinctus.

This is the largest anemone species, as far as oral disk diameter goes, with some specimens reaching more than one metre across. Found from Micronesia and Melanesia to East Africa, and Australia to the Ryukyu Islands of Japan.

RAPTOR RAPTURE

[The Hemisphere Kid]

Twice a year, thousands of raptors fill the skies over Tanjong Tuan, in Malaysia. Raptors are also called birds of prey. Eagles, buzzards, falcons, harriers, hawks, vultures and owls are all raptors. They have strong feet, sharp talons and keen eyesight. Five kinds of raptor usually visit Tanjong Tuan. They are the Crested Honey Buzzard, Grey-faced Buzzard, Black Baza, Japanese Sparrowhawk and Chinese Goshawk.

The raptors migrate between South-East Asia and Japan, China and Siberia. As they fly from Sumatra to Malaysia, they instinctively choose the shortest path across the Straits of Malacca, proving they are far from bird-brained! They avoid the dangers of long flights over the open sea but their journey is still not an easy one. Up to half of them may not make it home each year.

Why do these beautiful, powerful birds make this difficult trip twice a year? It’s because of the climate. In October and November, the northern parts of Asia start to get cold, so the raptors fly south to warmer countries such as Indonesia and the Philippines. In February and March, the northern regions warm up again and the birds return home to breed.

Luckily, raptors are some of Nature’s most skillful and spectacular fliers. They soar upwards on thermals -- columns of hot air rising from the ground -- and glide from one thermal to the next. This means they don’t have to waste energy flapping their wings to fly. And watching them circle and swoop is a thrilling sight for us!

You may wonder how the birds know which way home is. That question puzzled humans for thousands of years. Today, scientists have discovered that birds use the Earth’s magnetic field, the movement of the sun and stars and clues such as winds, smells, sights and sounds to guide them.

The Crested Honey-Buzzard, which gets its name from its fondness for eating the larvae of honey bees and wasps, is the largest (61 cm/24 in) raptor you might see at Tanjong Tuan. You can recognize this raptor by the small crest of feathers on the back of its head. Although it has a loud, high-pitched, it is usually silent during migration. It likes to fly in a group with other Crested Honey-Buzzards, often in a long queue.

You can recognize the Grey-faced Buzzard (46 cm/18 in) by its very long wings and strong markings. It also makes a unique “chi-kwee” call. Some people think it not only eats lizards and insects, but also rats!

The Black Baza is a smallish (33 cm/13 in) black-and-white raptor that likes to travel with its friends and family close around it. It will eat not only insects, but also small vertebrates and even other birds.

The Japanese Sparrowhawk is the smallest raptor you will see, reaching only 25-30 cm or 10-12 inches in height. Its small size, though, does not indicate a meek character! It likes to feed on other birds, including swallows and doves. It prefers to live alone, and migrates in widely scattered flocks.

You might also see the little (36 cm/14 in) grey-and-white Chinese Goshawk, although not many of them make the trip. When they do, they often join a flock of Japanese Sparrowhawks, which outnumber them by nine times. Unlike many other raptors, the Chinese Goshawk hunts for prey from a perch in a tree, not in flight.

Raptors are threatened by hunting and the destruction of their habitat. The forest at Tanjong Tuan is a wildlife refuge and bird sanctuary, but it is still shrinking. It is the last such forest in Malacca. Without it, the raptors will have no safe place to stop on their difficult journey.

The Malaysian Nature Society holds a Raptor Watch Week each year. The last one was from 3 to 5 March, 2001. The event includes educational programmes about the birds and an organized bird count by volunteers. Last year, 2,606 raptors flew over Tanjong Tuan. This information helps environmentalists plan how to protect these amazing birds.

If you go next year, you can count the raptors you see and help save them while having a lot of fun! Meanwhile, you can learn more about the raptor migration at the website of the Malaysian Nature Society at www.mns.org.my.

Fast Facts
• Of the world’s 292 raptor species, almost half live in tropical rainforests
• Tanjong Tuan is the largest bird migration in Asia
• 2,441 Crested Honey Buzzards were counted in 2000
• The second-largest group was of 145 Black Bazas
• Other types of birds seen: blue-tailed bee eaters, blue-throated bee eaters, swifts, swallows