EX EW CR EN VU NT LC O Eurasian Beaver Castor fiber Easy to catch and traditionally of high commercial value the Eurasian beaver has been heavily hunted in the past Today threats include habitat loss and water pollution but reintroductions are taking place and the species has been restored to a wide area of Europe Beaver furs are warm and make good clothes Beaver meat is also edible and the animals produce an oily scent called castoreum that was once widely prized as a traditional medicine Beavers are in fact so useful to people that for centuries they were hunted and trapped in large numbers and as a result were driven to extinction over much of Europe In Britain for example the last animals were killed before the start of the 16th century By the early 20th century the world population of the Eurasian species had fallen to about 1,500 animals dispersed across five main sites with a few more in Siberia and western China DATA PANEL Eurasian beaver Castor fiber Family Castoridae World population About 650,000 Distribution Widespread although patchy from France to China Mediterranean countries north to Scandinavia Habitat Broad river valleys swamps and floodplains where trees are found beside slow-flowing water Size Length head body 30 36 in 75 90 cm tail 11 16 in 28 38 cm Weight up to 84 lb 38 kg Form Heavy body with dark fur and a broad flattened tail Large orange incisor teeth small ears and eyes set near the top of the head Diet Plant material mostly grasses leaves and twigs over 300 different species have been recorded Breeding One litter per year of up to 8 young usually 4 5 mature at just under 2 years Life span 10 years in wild up to 25 or more in captivity Related endangered species No close relatives that are endangered Status IUCN LC 8 The demise of the Eurasian beaver has now been halted by effective protection measures and the species fortunes have been revived by many successful reintroduction projects So far beavers have been restored to 13 European countries including Latvia the Netherlands France and Hungary all of which now have thriving new beaver populations Sweden has imported some animals from Norway while others have been released in Lapland although their chances of survival so far north are precarious There are now about 650,000 Eurasian beavers altogether mostly in Europe although a few can be found in Central Asia Some even live in semiurban areas There is a colony along a riverbank below the flight path into Geneva Airport After asking the public for their views a trial release was organized in Knapdale Scotland where 16 beavers were released into the wild in 2009 and seem to be thriving Shaping the Environment Eurasian beavers live in small colonies of closely related animals Although they sometimes use log piles for their dens they do not build dams like their North American cousins preferring instead to dig burrows Nevertheless each fall they gnaw and fell trees setting up stores of twigs and leaves for the winter an activity that has a major effect on their environment In summer they feed on aquatic plants more than bark but can still cause damage to trees and sometimes to crops as well Although some of the beaver’s habits can be destructive to the
environment the same activities actually assist the survival of other animals By felling trees beavers create open clearings stimulating new growth that provides an ideal environment for warblers insects and shy mammals that find it difficult to live in unmodified forest The beaver’s large burrows can cause flooding and bank destruction but beavers also obstruct the water flow which is helpful to some species In good beaver habitat there may be one colony every 500 yards 450 m along a riverbank in poor conditions the gap between colonies may be over 3 miles 5 km New Hazards Although Eurasian beavers are still killed in some countries hunting is no longer a serious problem for the species Today there is a new danger in the increasing volume of road traffic The effects of road accidents can be particularly severe often wiping out whole families as they move between isolated ponds Youngsters also disperse away from their birth colony when they are about two years old sometimes traveling over 60 miles 100 km to find a new home In much of modern Europe such journeys are almost impossible to make without crossing roads and many young beavers are killed as a result There is also a new threat from detergent pollutants in the water which may interfere with the vital insulation provided by the beaver’s fur A potential problem for the future is that the American beaver was introduced to Finland in 1937 before it was realised it was a different species The two species do not interbreed but they do compete with each other for food resources EURASIAN BEAVER Beavers are at risk from natural hazards such as getting trapped under the ice in winter Natural predators like wolves do them little harm A greater danger is posed by highway traffic 9
EX EW CR EN VU NT LC O Eurasian Red Squirrel Sciurus vulgaris Red squirrels are common across Europe but are rapidly being replaced by American gray squirrels in Britain Such a fate may also overtake their continental cousins Only 100 years ago the red squirrel was common and the only squirrel in Britain and across continental Europe Now it is extinct in southern England except on three islands off the coast It remains common in Scottish forests and is still found in northern England although its numbers there are declining fast Apart from these areas it survives in a few scattered localities in Wales and eastern and central England In its place has come the American gray squirrel introduced to Britain between 1876 and 1929 The American gray has proved a highly successful invader becoming the squirrel commonly seen in most British woodlands parks gardens and even in the middle of cities DATA PANEL Eurasian red squirrel European red squirrel Sciurus vulgaris Family Sciuridae World population Probably at least 2 million spread over a huge area Distribution Europe and Asia from Britain east to China and northern Japan Habitat Forest especially coniferous forest Size Length head body 7 10 in 18 24 cm tail 5 8 in 14 20 cm Weight 9 12 oz 250 350 g Form Bright chestnut red in summer darker in winter large bushy tail and in winter prominent ear tufts Diet Pine seeds nuts fruit and fungi occasionally insects and birds eggs Breeding Usually 3 but up to 8 young per litter 1 or sometimes 2 litters per year after a gestation period of 5 6 weeks Life span up to 7 years in the wild but many die young 10 years in captivity Related endangered species Some local populations and subspecies of squirrels and chipmunks in the U S are Critically Endangered Endangered or Vulnerable but as with the Eurasian red squirrel whole species are not at risk Status IUCN LC 10 Many people blame the grays for attacking and driving out the native red squirrel or for passing on fatal diseases In fact there is no evidence that it is guilty of either of these crimes although one natural disease that kills red squirrels does not affect grays The main problem seems to be that while the European red squirrel is satisfactorily adapted to life in coniferous woodlands it is simply less well equipped than the gray to survive in deciduous forests Gray squirrels originated in the hardwood forests of North America and are at home in similar woodland areas of lowland Britain While the reds can survive in deciduous forests on their own they are at a disadvantage in such environments when they face competition from the grays The result is that once the grays spread into an area the reds disappear within about 15 years Attempts to reintroduce them back into the areas from which they disappeared have not been successful A Question of Adaptation One major problem is that red squirrels cannot digest acorns properly Acorns are the main food available in the fall in most lowland forests in Britain Grays thrive on them and they also compete for hazelnuts the reds favorite food in deciduous woodland Since gray squirrels normally live at double the population densities of reds they eat at least twice as many nuts leaving the latter with insufficient food resources Eurasian red squirrels feed mainly in the treetops so they cannot afford to store much fat for the winter without running the risk of becoming clumsy
EURASIAN RED SQUIRREL climbers Grays on the other hand forage more on the ground and so can accumulate larger fat reserves because agility in the treetops is less important for them With less fat to tide them over periods of scarcity reds have to feed regularly whatever the weather Since they do most of their foraging in the trees they are also limited in the range of food available to them In contrast the ground-feeding grays not only have access to a wider selection of forage but can also find enough to meet their needs in a much shorter time a substantial advantage in spells of bad weather Ironically native red squirrels have simply turned out to be less well adapted to cope with the British weather and living conditions than the invasive grays and so they have lost out in competition with the newcomers Red squirrels are now absent from most parts of England and many areas of Wales although the population in Scotland about 100,000 in 2008 seems much more secure The Eurasian red squirrel spends much of its time foraging in trees it comes down to the ground occasionally to bury nuts Still more alarmingly grays are now spreading across northern Italy The species was introduced there in 1948 and in 1966 near Turin If they spread the grays will threaten red squirrels throughout the rest of Europe Attempts to curb the threat to Eurasian red squirrels by eliminating the grays have been stopped by animal rights supporters in some places they have managed to win legal backing for their efforts to halt the killings The situation raises a difficult moral dilemma If the few hundred introduced gray squirrels have a right to life should the threatened red squirrel population not benefit from similar protection And if so how can their future be assured in the face of a challenge from outside except by culling the newcomers 11
