A Otters are semiaquatic (or in the case of the sea otter, aquatic) mammals. They are members of the Mustelid family which includes badgers, polecats, martens, weasels, stoats and minks, and have inhabited the earth for the last 30 million years and over the years have undergone subtle changes to the carnivore bodies to exploit the rich aquatic environment. Otters have long thin body and short legs—ideal for pushing dense undergrowth or hunting in tunnels. An adult male may be up to 4 feet long and 30 pounds. Females are smaller, around 16 pounds typically. The Eurasian otter’s nose is about the smallest among the otter species and has a characteristic shape described as a shallow “W”. An otter’s tail (or rudder, or stern) is stout at the base and tapers towards the tip where it flattens. This forms part of the propulsion unit when swimming fast under water. Otter fur consists of two types of hair: stout guard hairs which form a waterproof outer covering, and under-fur which is dense and fine, equivalent to an otter’s thermal underwear. The fur must be kept in good condition by grooming. Sea water reduces the waterproofing and insulating qualities of otter fur when salt water gets in the fur. This is why freshwater pools are important to otters living on the coast:. After swimming, they wash the salts off in the pools and then squirm on the ground to rub dry against vegetation.

B Scent is used for hunting on land, for communication and for detecting danger. Otterine sense of smell is likely to be similar in sensitivity to dogs. Otters have small eyes and are probably short-sighted on land. But they do have the ability to modify the shape of the lens in the eye to make it more spherical, and hence overcome the refraction of water. In clear water and good light, otters can hunt fish by sight. The otter’s eyes and nostrils arc placed high on its head so that it can see and breathe even when the rest of the body is submerged. The long whiskers growing around the muzzle are used to detect the presence of fish. They detect regular vibrations caused by the beat of the fish’s tail as it swims away. This allows otters to hunt even in very murky water. Underwater, the otter holds its legs against the body, except for steering, and the hind end of the body is flexed in a series of vertical undulations. River otters have webbing which extends for much of the length of each digit, though not to the very end. Giant otters and sea otters have even more prominent webs, while the Asian short-clawed otter has no webbing—they hunt for shrimps in ditches and paddy fields so they don’t need the swimming speed. Otter ears are protected by valves which close them against water pressure.

C A number of constraints and preferences limit suitable habitats for otters. Water is a must and the rivers must be large enough to support a healthy population of fish. Being such shy and wary crea-tures, they will prefer territories where man’s activities do not impinge greatly. Of course, there must also be no other otter already in residence—this has only become significant again recently as populations start to recover. A typical range for a male river otter might be 25km of river, a female’s range less than half this. However, the productivity of the river affects this hugely and one study found male ranges between 12 and 80km. Coastal otters have a much more abundant food supply and ranges for males and females may be just a few kilometers of coastline. Because male ranges are usually larger, a male otter may find his range overlaps with two or three females. Otters will eat anything that they can get hold of—there are records of sparrows and snakes and slugs being gobbled. Apart from fish the most common prey are crayfish, crabs and water birds. Small mammals are occasionally taken, most commonly rabbits but sometimes even moles.

D Eurasian otters will breed any time where food is readily available. In places where condition is more severe, Sweden for example where the lakes are frozen for much of winter, cubs are bom in Spring. This ensures that they are well grown before severe weather returns. In the Shetlands, cubs are born in summer when fish is more abundant. Though otters can breed every year, some do not. Again, this depends on food availability. Other factors such as food range and quality of the female may have an effect. Gestation for Eurasian otter is 63 days, with the exception of North American river otter whose embryos may undergo delayed implantation.

E Otters normally give birth in more secure dens to avoid disturbances. Nests are lined with bedding (reeds, waterside plants, grass) to keep the cubs warm while mummy is away feeding. Litter Size varies between 1 and 5 (2 or 3 being the most common). For some unknown reason, coastal otters tend to produce smaller litters. At five weeks they open their eyes—a tiny cub of 700g. At seven weeks they’re weaned onto solid food. At ten weeks they leave the nest, blinking into daylight for the first time. After three months they finally meet the water and learn to swim. After eight months they are hunting, though the mother still provides a lot of food herself. Finally, after nine months she can chase them all away with a clear conscience, and relax—until the next fella shows up.

F The plight of the British otter was recognised in the early 60s, but it wasn’t until the late 70s that the chief cause was discovered. Pesticides, such as dieldrin and aldrin, were first used in ‘1955 in agriculture and other industries—these chemicals are very persistent and had already been recognised as the cause of huge declines in the population of peregrine falcons, sparrowhawks and other predators. The pesticides entered the river systems and the food chain—micro-organisms, fish and finally otters, with every step increasing the concentration of the chemicals. From 1962 the chemicals were phased out, but while some species recovered quickly, otter numbers did not—and continued to fall into the 80s. This was probably due mainly to habitat destruction and road deaths. Acting on populations fragmented by the sudden decimation in the 50s and 60s, the loss of just a handful of otters in one area can make an entire population enviable and spell the end.

G Otter numbers are recovering all around Britain—populations are growing again in the few areas where they had remained and have expanded from those areas into the rest of the country. This is almost entirely due to law and conservation efforts, slowing down and reversing the destruction of suitable otter habitat and reintroductions from captive breeding programs. Releasing captive-bred otters is seen by many as a last resort. The argument runs that where there is no suitable habitat for them they will not survive after release and when¹ there is suitable habitat;, natural populations should be able to expand into the area. However, reintroducing animals into a fragmented and fragile population may add just enough impetus for it to stabilise and expand, rather than die out. This is what the Otter Trust accomplished in Norfolk, where the otter population may have been as low as twenty animals at the beginning of the 1980s. The Otter Trust has now finished its captive breeding program entirely. Great news because it means it is no longer’ needed.

The wonder plant with an uncertain future: more than a billion people rely on bamboo for either their shelter or income, while many endangered species depend on it for their survival. Despite its apparent abundance, a new report says that species of bamboo may be under serious threat.

A

Every year, during the rainy season, the mountain gorillas of Central Africa migrate to the foothills and lower slopes of the Virunga Mountains to graze on bamboo. For the 650 0r so that remain in the wild, it’s a vital food source. Although there are at almost 150 types of plant, as well as various insects and other invertebrates, bamboo accounts for up t0 90 percent of their diet at this time of year. Without it, says Ian Redmond, chairman of the Ape Alliance, their chances of survival would be reduced significantly. Gorillas aren’t the only locals keen on bamboo. For the people who live close to the Virungas, it’s a valuable and versatile raw material used for building houses and making household items such as mats and baskets. But in the past 100 years or so, resources have come under increasing pressure as populations have exploded and large areas of bamboo forest have been cleared to make way for farms and commercial plantations.
B

Sadly, this isn’t an isolated story. All over the world, the ranges of many bamboo species appear to be shrinking, endangering the people and animals that depend  upon  them.  But  despite  bamboo’s  importance,  we  know surprisingly little about it. A recent report published by the UN Environment Programme (UNEP) and the Inter-national Network for Bamboo and Rattan (INBAR) has revealed just how profound is our ignorance of global bamboo resources, particularly in relation to conservation. There are almost 1,600 recognized species of bamboo, but the report concentrated on the 1,200 or so woody varieties distinguished by the strong stems, or culms, that most people associate with this versatile plant. Of these, only 38 ‘priority species’ identified for their commercial value have been the subject of any real scientific research, and this  has focused mostly on matters relating to their viability as a commodity. This problem isn’t confined to bamboo. Compared to the work carried out on animals, the  science  of assessing the conservation status of plants is still in its infancy. “People have only started looking hard at this during the past 10-15 years, and only now are they getting a handle on how to go about it systematically,” says Dr. Valerie Kapos, one of the report’s authors and a senior adviser in forest ecology and conservation to the UNEP.

C

Bamboo is a type of grass. It comes in a wide variety of forms, ranging in height from 30 centimeters to more than 40 meters. It is also the world’s fastest-growing woody plant; some species can grow more than a meter in a day. Bamboo’s ecological role extends beyond providing food and habitat for animals. Bamboo tends to grow in stands made up of groups of individual plants that grow from root systems known as rhizomes. Its extensive rhizome systems, which tie in the top layers of the soil, are crucial in preventing soil erosion. And there is growing evidence that bamboo plays an important part in determining forest structure and dynamics. “Bamboo’s pattern of mass flowering and mass death leaves behind large areas of dry biomass that attract wildfire,” says Kapos. “When these burn, they create patches of open ground within the forest far bigger than would be left by a fallen tree.”Patchiness helps to preserve diversity because certain plant species do better during the early stages of regeneration when there are gaps in the canopy.

D

However, bamboo’s most immediate significance lies in its economic value. Modern processing techniques mean that it can be used in a variety of ways, for example, as flooring and laminates. One of the fastest growing bamboo products  is  paper-25  percent  of  paper  produced  in  India  is  made  from bamboo fiber, and in Brazil, 100,000 hectares of bamboo are grown for its production. Of course, bamboo’s main function has always been in domestic applications, and as a locally traded commodity it’s worth about $4.5billion annually. Because of its versatility, flexibility and strength (its tensile strength compares to that of some steel), it has traditionally been used in construction. Today, more than one billion people worldwide live in bamboo houses. Bamboo is often the only readily available raw material for people in many developing countries, says Chris Stapleton, a research associate at the Royal Botanic Gardens. “Bamboo can be harvested from forest areas or grown quickly elsewhere, and then converted simply without expensive machinery or facilities,” he says. “In this way, it contributes substantially to poverty alleviation and wealth creation.”

E

Given bamboo’s value in economic and ecological terms, the picture painted by theUNEP report is all the more worrying. But keen horticulturists will spot an apparent contradiction here. Those who’ve followed the recent vogue for cultivating exotic species in their gardens will point out that if it isn’t kept in check, bamboo can cause real problems. “In a lot of places, the people who live with bamboo don’t perceive it as being endangered in any way,” says Kapos. “In fact, a lot of bamboo species are actually very invasive if they’ve been introduced.”So why are so many species endangered? There are two separate issues here, says Ray Townsend, vice president of the British Bamboo Society and arboretum manager at the Royal Botanic Gardens. “Some plants are threatened because they can’t survive in the habitat-they aren’t strong enough or there aren’t enough of them, perhaps. But bamboo can take care of itself-it is strong enough to survive if left alone. What is under threat is its habitat.”It is the physical disturbance that is the threat to bamboo, says Kapos. “When forest goes, it is converted into something else: there isn’t anywhere for forest plants such as bamboo to grow if you create a cattle pasture.”

F 

Around the world, bamboo species are routinely protected as part of forest eco-systems in national parks and reserves, but there is next to nothing that protects bamboo in the wild for its own sake. However, some small steps are being taken to address this situation. The UNEP-INBAR report will help conservationists to establish effective measures aimed at protecting valuable wild bamboo species. Townsend, too, sees the UNEP report as an important step forward in promoting the cause of bamboo conservation. “Until now, bamboo has been perceived as a second-class plant. When you talk about places such as the Amazon, everyone always thinks about the hardwoods. Of course these are significant, but there is a tendency to overlook the plants they are associated with, which are often bamboo species. In many ways, it is the most important plant known to man. I can’t think of another plant that is used so much and is so commercially important in so many countries.”He believes that the most important first step is to get scientists into the field. “We need to go out there, look at these plants and see how they survive and then use that information to conserve them for the future.”