WHERE WHOOPING CRANES CHEAT EXTINCTION

Some of the most majestic birds on the planet congregate each winter just off the narrow road to a cavernous barbecue restaurant, on an area of salt marches stretching into the chocolate-coloured waters of the Gulf of Mexico. Standing 1.5 metres in the shallow water, occasionally opening their wings to a span wider than that of a pickup truck, these are whooping cranes, part of a population that still numbers fewer than 500 after slowly making its way back from the brink of extinction. They arrive here, at Aransas Bay in Texas, in tight-knit family units after flying 3,900 km from their summer home in the Northwest Territories of Canada.

Catering to people who go on crane-watching tours is relatively new for Port Aransas and Rockport, the small Texas towns near the Aransas National Wildlife Refuge, not far from Corpus Christi. Altogether, including wildlife lov ers not specifically seeking the whooping cranes, about

1. Visitors from around the globe travel to the Aransas National Wildlife Refuge each year, contributing some 5 mil lion dollars to the local economy.

The more typical trip into the marches a few decades ago would have carried hunters seeking other more common wa terfowl, for other, more traditional purposes. But Texans have learned that there can be more money in whooping cranes and other unusual birds — and in the people who will travel thousands of kilometers to see them.

Whooping cranes — the tallest North American birds — are the family type. They mate for life and can live 25 years or more in the wild. The migration of cranes has been studied in awe for centuries, taking place on every continent except South America and Antarctica. The 15 species of the crane family, heralded in myth as symbols of longevity and good fortune, include far-flung members like the relatively small demoiselle crane that breeds in southeastern Siberia and winters in East Africa and Iraq, and the renowned red- crowned crane of Japan, whose crimson radiance was, until recently, painted on the plane tails of Japan Airlines. (Cranes also inspired the logo of another airline, Lufthansa.)

Still, the cranes’ rarefied status among birds has not guaranteed their survival. Of the 15 surviving species, 11 are imperiled with the possibility of extinction, as the naturalist Peter Matthiessen described in drenching detail in his 2001 book on cranes, “The Birds of Heaven”. Yet none of the cranes, whether found in isolated Bhutan or the Mongo lian steppe, are as rare as Grus americana, the whooping crane of North America, and the largest flock of them, born and raised in the wild, spend their winters in the gulf marshes of Texas.

More than half a century ago, the ecologist Also Leopold tried to articulate the crane’s mystique. “Our ability to per ceive quality in nature begins, as in art, with the pretty,” he wrote in the late 1940’s, when the extinction of the whooping crane seemed imminent. “It expands through successive stages of the beautiful values as yet uncaptured by language. The quality of cranes lies, I think, in this higher gamut, as yet beyond the reach of words.”

MIGRANTS WITH GOLDEN WINGS HAVE THINNED OUT IN MEXICO

Contepec, Mexico — Homero Aridjis, a poet and naturalist, can remember years when monarch butterflies filled the streets here in his hometown like a living torrent of orange and black and stayed all winter on the fir-covered mountain ris ing above the village. “There used to be rivers of butterflies, but now there are years when there are no butterflies at all,” Mr. Aridjis said recently. “This is a village full of ghosts, not of people, but of nature, a paradise lost.”

Not only are there comparatively few monarchs in Con tepec, but the numbers that came for the winter at five other forest sanctuaries in central Mexico also fell sharply this year. Two storms killed most of the butterflies.

Biologists and naturalists warn that logging in Mexico and herbicides in the United States have endangered these almost miraculously migratory insects, which travel thousands of kilometers.

Hardier genetically altered corn and soybean crops in the United States and Canada have enabled farmers to use stronger herbicides to eliminate weeds. That has drastically depleted the supply of flowers on which the butterflies feed, as well as common milkweed, on which the monarch lays its eggs in the spring and summer and on which its larvae feed, several biologists say.

In August, as the days shorten, the last monarch genera tion hatched in the summer stops reproducing. The monarchs fly south to the forested hills in Michoacan and the State of Mexico. There, they find the perfect balance of coolness and humidity to remain alive for several months, without laying eggs. In February, they mate. In March, they return north to lay their eggs and die.

In Mexico, illegal logging in these protected forests has shrunk the monarchs’ habitat and forced the insects to high er elevations, where they are vulnerable to the cold.

Eleven biologists who study the monarch concluded, “Mo narchs have proven resilient to many environmental stresses, but the ongoing deterioration and loss of habitat in Mexico, the US and Canada has the potential to drive the population below sea level from which it can recover.”

One reason the monarch is in a precarious situation is poverty. Martin Uilshes Maya, a farmer from Contepec who loves the butterflies, is typical of many people in the region. He said he had about 4 hectares of land to feed his wife and two children. He grows enough corn and wheat, but the need for firewood sometimes drives him and his neighbours into the forest.

“Clearly, we are destroying the forest, but that is what life is giving us,” he said sadly. “It’s a very beautiful pheno menon, the butterflies, that gives us so much life. But we don’t have any way to make money of tourism.”

BIRDS

Climate change is likely to have both direct and indirect effects on birds. Higher temperatures can directly alter their life cycles. The loss of wetlands, beaches, and other habitat could have an equally important indirect effect, by making some regions less hospitable to birds than those regions are today.

As temperatures warm, birds will tend to inhabit more northerly areas (in the Northern Hemisphere). Data collected by the National Audubon Society’s Christmas Bird Count show that during years with warmer temperatures, the majority of bird species do not have to fly as far south for the winter. Warmer temperatures also allow birds to spend their sum mers on the Bobolink (a North American songbird). During summer, this bird is currently found throughout New Eng land, the states that border the Great Lakes, and north of a line stretching from Missouri to Idaho. With the projected climate changes under a doubling of carbon dioxide, the Bobolink would not be found south of the Great Lakes.

Warmer temperatures can also affect how birds respond to the change in seasons. Several types of birds that fly north to Michigan during spring now arrive two or three weeks earlier than in 1960. Scientists at the British Trust for Orni thology have found that 20 of 65 species of birds are laying their eggs an average of 9 days earlier today than in 1971. The earlier nesting appears to result in part because plants are flowering and growing leaves sooner, which in turn caus es earlier availability of the insects that these birds eat.

Scientists do not know whether birds will benefit from these changes. Earlier nesting means that birds will be a week or so older when the time comes to migrate south, which may improve their odds of survive their first winters. The chang ing climate, however, may impair the extent to which a bird’s life cycle is synchronized with its food supply. While birds can adjust to warmer temperatures by flying to more northern areas in any given year, the vegetation upon which they (or the insects they eat) rely may take decades or longer to adjust.

In some cases, the habitat upon which birds rely may not only fail to migrate north, it may be threatened in its current location. The loss of estuarine beaches caused by rising sea level would decrease available habitat for the least tern, an endangered species; the loss of these beaches also would decrease feeding areas for shore birds that rely on horseshoe crabs and other organisms found in inter-tidal areas. By decreasing estuarine fish and shellfish populations, the loss of coastal wetlands would decrease available food supplies; and the loss of wetlands would also decrease available habitat.

Similarly, the decline in prairie potholes would decrease duck populations. The prairie potholes in the northern Great Plains are responsible for breeding 50-80 per cent of the nation’s duck population. A drier climate would decrease the amount of open water ponds in this region, with a commensu rate reduction in duck populations.

IT’S JUST NOT NATURAL

Genetic modification can give us easy-peel oranges, cancer-fighting strawberries and blue potatoes. But if you don’t want your food fiddled about with, can you avoid it?

When you bite into an apple, do you ever wish it was a pineapple instead? Well, now you can have the best of both worlds. Australian scientists have created a fruit with the convenience of an apple and the taste of a pineapple. The aim of the Snack Apple is to persuade children to eat more fresh fruit and vegetables and it’s just one illustration of how far science is prepared to go in pursuit of this worthy ideal.

First on the scene was frozen-food company Iceland which came up with chocolate-flavoured carrots, made by freezing the vegetables with granules of chocolate sauce. And plant breeders have a range of mini-vegetables such as carrots, broccoli and cauliflower, which they hope will make them popular snack foods with youngsters and a healthier alternative to crisps.

But science can now do more than this and create new types of foods by means of genetic manipulation. A gene may1 be transferred from a different species in order to increase the nutritional value of the plant, or to make it more resist ant to pests and disease. Incredibly, scientists have used a gene from a fish to give antifreeze properties to tomatoes and so increase their growing season.

Despite the benefits, however, not everyone is in favour of genetically modified (6M) foods or “Frankenfoods”, as the media calls them. Because there are no long-term studies to prove the safety of GM foods, their long-term effect on human health is unknown. There is also a great deal of concern for the environment, with fears that GM crops might spread their genes by pollination to other plants grow ing nearby. This kind of genetic pollution would be very difficult to clean up.

There is particular controversy surrounding soya, a com mon ingredient in processed foodstuffs. One of the problems is that imports of soya from the US contain both GM and non-GM beans because it’s not thought practical to separate them at their source. It is therefore difficult to avoid GM soya because we don’t know which products contain it and which don’t. A large number of consumers object to this and have called for clearer labeling of GM products.

But should we reject all GM foods? There are plans to introduce more appealing products: peas which contain more vitamin С and broccoli, strawberries and tomatoes with more of the anti-cancer compound, sulphophane. We could also have blue potatoes. The genes that make one natural blue dye have recently been transferred from bacteria to flowers, so why not to food plants? Scientists are already working on blue roses using this technology. And if your main objection to fruit is the unpeelable orange, there are also plants for an orange that will practically peel itself.

BY MAPPING CAT’S GENES, MYSTERIES OF GENETIC ILLNESSES MAY UNRAVEL

Genetically speaking, every dog has already had its moment as the center of attention. In 2003, a poodle named Shadow became the first canine to have his genome mapped, and in 2004 a boxer Tasha became the second.

Now scientists are turning their attention to the genome of the domestic cat, and it is a cat named Cinnamon’s turn to donate a blood sample. Cinnamon comes from a carefully bred colony at the University of Missouri, and her lineage can be traced back for decades. Scientists therefore know exactly wheat they are getting when they look at her DNA.

Researchers hope to have the cat genome mapped by the end of the year and when the job is done, humans will be the ones to benefit.

Americans own more than 60 million cats, spend over four billion dollars a year on cat food and are so dedicated to feline health care that their veterinarians have identified more than 250 genetic diseases and hundreds of infectious agents that afflict them. The genome will contribute to knowledge with immediate practical application, not only for veterinarians and cat owners, but for geneticists, zoologists and conservationists.

Chopping up the DNA into tiny usable pieces in a process called library construction, and then putting it all back togeth er creates the map. The cat was chosen, among other reasons, for its importance as a medical model in studying human disease.

“The genes on the cat chromosome and the human chro mosome correspond to each other like two strings of beads made of different colours,” said Dr. Stephen J. O’Brien, chief of the Laboratory of Genomic Diversity of the National Cancer Institution, adding that cats have “the same genes, one after another, strung together across every chromosome.”

This resemblance means that many of the cat’s genetic diseases are inherited exactly the same way as genetic illnesses in humans. Diabetes, hemophilia and lupus, for example, have precise genetic homologues in cats.

Cat retroviruses, like those that cause feline leukemia and feline sarcoma, although slightly different in their gene structure from the human versions, produce lesions that look almost identical to human cancers.

Feline immunodeficiency virus, or F.I.V., resembles H.I.V. so closely that it follows the same progression that, untreated, leads to the wasting syndrome of AIDS in humans.

Cats also get feline versions of many other human infec tious diseases, including rotavirus, poxvirus, herpes, Q-fever, chlamydiosis and dozens more. They are resistant to anthrax infection. Once the genome is mapped, said Dr. O’Brien, “re search on feline stem cells will blossom, along with gene therapy applications.”

“At least froin a genomic perspective,” he added, “cats share a striking ancient affinity with humankind.”

THE SEARCH FOR NEW WAYS TO KILL PAIN

Despite all the advances of modern medicine, the main drugs used to fight pain today are essentially the same as those used in ancient times.

Hippocrates wrote about the pain-soothing effects of wil low bark and leaves as early as 400 BC. Opium was cultivated long before that. Aspirin and morphine, based on the active ingredients in these traditional remedies, were isolated in the 1800’s and helped form the foundation of the modern phar maceutical industry.

But scientists are now trying to find new ways of fight ing pain. The effort has been given new life by the recent withdrawal of Vioxx and the questions surrounding the safety of similar pills like Celebrex and Bextra. Those con cerns come on top of the problems of abuse of narcotic painkillers like OxyContin.

Some new treatments may come from things in nature that soothe or sting, like marijuana, hot chili peppers, and deadly; toxins of snails and fish.

Doctors classify pain into various categories, but there are two main types of persistent pain. One, sometimes called nociceptive pain, results from damage to tissues. The other, called neuropathic pain, results from damage to the nerves themselves.

Opioids, like Morphine or OxyContin, are used for more severe tissue-type pain. But the drugs have side effects and can lead to addictions.

Aspirin and drugs like naproxen and ibuprofen are called nonsteroidal anti-inflammatory drugs, or Nsaid’s, and are used for less serious pain. They block certain chemicals that contribute to inflammation, but they can also cause stomach ulcers and bleeding.

Vioxx, Celebrex and Bextra are newer types of Nsaid’s called cox-2 inhibitors, which were intended to cause fewer gastrointestinal problems. But Vioxx was found to raise the risk of heart attacks and stroke, and there is concern the other cox-2 inhibitors may do so as well.

Some efforts to develop better pain relievers focus on variations of the existing treatments. But experts say there is a need for totally new categories of pain relievers.

One such drug, called Prialt, was approved by the United States Food and Drug Administration in December 2004. It is a synthetic version of a toxin that a South Pacific marine snail uses to paralyze its prey. The drug impedes the transmission of pain signals through the nerves by blocking channels through which calcium ions flow into nerve cells. It is said to be nonaddictive and 1,000 times as potent as morphine.

Potent, yes, but also problematic. To minimize side ef fects like heart rhythm disturbances and hallucinations, the drug must be injected into the fluid surrounding the spinal cord. That will limit its use.

Another approach is to block sodium channels. A group of scientists in the USA is testing tiny amounts of a toxin from the fugu, or puffer fish, a dangerous delicacy in Japan.

Chili peppers are less deadly, but their main ingredient, capsaicin, can cause intense pain when rubbed on skin. Expo sure desensitizes and temporarily damages the pain sensors.

Derivatives of marijuana are also being looked at. A group of scientists from Lexington is testing a drug based on a chemical, THT, the main ingredient in marijuana. The healthy volunteers, the drug caused no psychoactive effects. But there has been only one trial showing that the drug provided better pain relief than a placebo.

A DARWINIAN LOOK AT WAILING BABIES

Parents of wailing babies, take comfort: you are not alone.

Chimpanzee babies fuss. Sea gull chicks squawk. Burying beetle larvae tape their parents’ legs. Throughout the animal kingdom, babies know how to get their parents’ attention. Exactly why evolution has produced all this squawking and tapping is a question many biologists are now trying to an swer. Someday, that answer may solve the mystery of fussy, colicky babies.

“It may point researchers in the right direction to find the causes of excessive crying,” said Dr. Joseph Solitis, a bioacoustics expert at Disney’s Animal Kingdom in Lake Buena Vista, Florida. Not long ago, he published an article on the evolution of crying.

When a young animal relies on its parents for survival, they need a constant stream of information to decide how to care for it. A young animal sends its parents signals.

Young animal# vary in how much they communicate with their parents, and studies with mice, beetles and monkeys show that variation is communicating with parents is partly based on genes. You might expect that natural selection would favour genes for noisier children, since they would get more attention. But if the signals of offspring became totally unre liable, parents would no longer benefit from paying attention. Some evolutionary biologists have proposed that natural selec tion should therefore favour so-called honest advertisements.

These advertisements demand energy, meaning that a young animal cannot make them without paying a real cost. Dr. Rebecca Kilner of the University of Cambridge in England was able to show that these costs exist by studying canaries. She removed 60 canary chicks from their nests and fed them by hand for six hours. She fed some birds quickly but let others beg for up to a minute. She found that the longer a canary had to beg, the less weight it put on, despite the fact that all the birds were eating the same number of calories.

Some biologists have speculated that these advertisements may not just tell a parent which offspring are hungry. They might also show that they are healthy and vigorous, and therefore worth some extra investment.

But there may also be some circumstances in which it pays for babies to fake it. The babies of rhesus macaque monkeys cry out a lot to their mothers, and tend to cry even more around the time their mothers wean them — making it possible for the mothers to have more children. The mothers begin to ignore most of their babies’ distress calls, since most turn out to be false alarms.

Dr. Wells points out that human babies are under par ticularly intense pressure to get food and care from their parents compared with other primates. Human brains are very large and demand a lot of energy. Making matters worse, human babies grow rapidly in the first year of life.

Why then do babies cry even when they are healthy and full? Researchers all agree that their ideas about crying still wait to be tested.

ANIMAL HEALTH Nutrition of Horses

Proper nutrition is essential for the health of horses. Deficient or imbalanced rations or poor feeding manage ment can cause deficiency diseases, decreased resistance to infectious diseases, predisposition to lameness, decreased performance, and digestive problems such as colic and en- terotoxemia.

Digestion — the process which releases nutrients from feeds for use by the body — begins in the mouth where food is ground and mixed with saliva. Proper dental care such as floating of teeth is necessary so food is chewed properly. Food then travels to the stomach where the chem ical breakdown starts. The horse’s stomach is relatively small and horses seldom vomit. Overfeeding can cause dis tention of the stomach and signs of colic (a general name for abdominal pain). Horses fed large amounts of grain should be fed two or more times daily, to reduce the inci dence of colic.

The small intestine is a major site of digestion and ab sorption of many nutrients. Good parasite control is neces sary for optimum function of the small intestine. Parasites not only reduce feed utilisation, but can cause colic.

The large intestine consists of the cecum and colon. It has a large population of micro-organisms (bacteria and proto zoa) which digest the fiber in plant materials. If feed changes are made rapidly, the micro-organisms do not have time to adapt. Excessive gas production, colic, and diarrhea may result: so make changes gradually. A change period of 10 days is best, but 5 may suffice.

Nutrient Guidelines. The horse requires energy, protein, vitamins, minerals, and water. Overfeeding and underfeed ing of energy are two of the most common feeding mistakes. Forages — such as hay and pasture — and grains are the most frequent sources of energy.

Grains usually contain 40 to 60 per cent more energy per pound of dry matter than do forages. But forages may con tain adequate concentrations of energy to supply the energy needs of some classes of horses.

A non-pregnant, non-lactating mature horse that is not working hard could maintain body weight if fed 1 XA to 2 lbs of hay per 100 lbs of body weight. A pregnant mare (last third of gestation) may require some grain, perhaps XA to % lb per 100 lbs of body weight in addition to hay. The intake of hay may also slightly decrease because the fetus fills up some of the body cavity. But some pregnant mares can obtain all the energy needed from good quality hay.

The amount of energy required by the lactating mare depends on the amount of milk she is producing. An average mare may require 'A to 1 lb of grain per 100 lbs of body weight in addition to hay or pasture.

A hard working horse such as a racehorse at the track may need IV2 lbs of grain and VA lbs of hay per 100 lbs of body weight. Rapidly growing foals may eat V* lb of hay and VA lbs of grain per 100 lbs of body weight.

The above guidelines are only rough estimates. There is considerable variation in energy metabolism among horses. The energy content among hays varies greatly. Energy re quirements differ according to environmental temperature.

The eye of the feeder is important. К the horses are too fat, decrease the amount of grain; if too thin, feed more grain.

Keeping records of body weight obtained from scales or by estimating with tapes around the heart girth can be very useful when evaluating a feeding programme.

Protein is needed for maintenance and for production of new tissue. A deficiency of protein decreases rate of gain, causes a rough hair coat, and decreases appetite.

The young horse requires the greatest concentration of protein in the ration. The National Research Council recom mends that horses weaned at 3 months of age be fed diets containing at least 16 per cent protein and horses weaned at 6 months need 14.5 per cent. Mature horses at maintenance need only 8 per cent protein. Pregnant or lactating mares need 11 to 12.5 per cent protein. Work does not greatly increase the protein requirement.

Proteins are composed of smaller units called amino acids. Feed protein is digested in the animal’s body. Feed proteins that contain a good mixture of amino acids are called “high quality” proteins, those with a poor mixture are called “low quality” proteins.

Soybean meal is a reasonable source of amino acids for horses. Other vegetable protein source such as cottonseed meal and linseed meal contain a lower concentration of the amino acid lysine than that found in soybean meal.

Minerals are required for many functions. Two minerals that are required in greatest amounts are calcium and phos phorus. One of their primary functions is the formation of bone, but they have many other important roles.

An excess of phosphorus decreases calcium utilisation and may result in nutritional secondary hyperparathyroidism (NSH) if diet has a low level of calcium. Horses with NSH have weak bones, become lame, and may have an enlarged head because of invasion of fibrous connective tissue.

Legume hays may contain 1 to 1.5 per cent calcium, but grass hay may contain only 3 to 4 per cent calcium. Grains contain almost no calcium.

Limestone is an excellent source of calcium for horses. Dicalcium phosphate contains calcium and phosphorus.