ENHS Nature Trails May 2003 Article 5

Delights and Ironies in an Alien Land
by Reida Kimmel

Foreign bird songs are so much more noticeable. Because they are different, they force themselves into your consciousness. I am overwhelmed by the beauty of the thrush family songs over here in England. Recently, at Bodnant Garden in Wales, three mistle thrushes (Turdus viscivorus), in three separate trees, sang out their territorial claims. A rather large grey-brown bird with a boldly spotted breast, the mistle thrush has a song which is both very long and loud. Further along a garden path, amidst the gaudy rhododendron blooms, my favorite songbird, the robin, (Erithacus rebeculd) came out of the bushes to visit, and sang beautifully to us at a distance of about two feet from our faces. Another member of the thrush family, the English robin is tiny, with incredibly dainty beak and legs. The males are very bold and vocal all year, and seem to be rather puffy and round in shape, quite adorable. If I waken a little before dawn in our Cambridge city center flat, I hear choruses of the most beautiful song coming from the local male blackbirds. Turdus merula, a beloved songbird all over the country, is as happy in the cities as in the country. The male is coal black with a bright yellow eye ring, while the female is dull brown. Sadly this bird is in decline all over its range. No one quite knows why.

Many once common species of English birds are in decline. Some people blame cats, others magpies. Most likely the heavy use of herbicides and pesticides combined with loss of habitat and suitable nesting sites are more significant factors. Loved for its "cheerful chirrup" and the males' pretty markings, Passer domesticus, the house sparrow, is in decline, especially in the towns. Ironically, this is the same "English" sparrow that has taken over the urban scene in North America at the expense of our native birds.

Not in decline, in fact I saw a 'large' flock of about twenty birds at Norwich Cathedral yesterday, is the starling (Sternus vulgaris). Nature lovers in Scotland's Outer Hebrides are urged to appreciate the especially large size and brilliant plumage of their particular race of starlings. Actually, if you look at a male starling in breeding plumage, it is a very pretty bird, and its bustling walking gait is quite amusing. The lesson to be learned, as always, is that transplanting species which are innocuous in their homelands, can be a disaster.

If England has given us plagues of starlings, house sparrows, ivy, gorse and purple loosestrife, the Americas have been generous in return. Canada geese have become all too common in recent years, and breed in most of Britain's inland waters. The American grey squirrel (Scurrus carolinensis) was introduced in the 19th century by sportsmen landowners and has managed to drive the native red squirrel, Scurrus vulgaris (Squirrel Nutkin in Beatrix Potter's charming story), to near extinction. The red squirrel is holding its own only in parts of the Scottish Highlands and on the National Trust's Brownsea Island off the South Coast, where grey squirrels have not penetrated. The American mink, escaped long ago from fur farms, is a serious threat to wildlife all over Northern Europe. In Britain it has been responsible in part for the eighty-eight per cent decline in the population of water voles since 1990. The water vole, Arvicola tenestris (the Mole in the Wind and the Willows), is probably Britain's fastest declining mammalian species.

Blooming gloriously in May and June, rhododendron escapees from 19th century garden importations, paint the hills of Wales and Western Ireland with shades of lilac and purple. They must be grubbed out laboriously to make room for native flowers and shrubs, including our nemesis, ivy. More recently, goldenrod, a garden favorite, has made its way into the countryside.

Not all of England's unpleasant imports come from North America. Myocastor coupus, the South American nutria, another escapee from fur farms, is common in East Anglia where its burrows and voracious grazing damage river banks just as they do in the West Eugene Wetlands. Neither the black rat (Rattus rattus) nor the Norwegian rat (Rattus norvegicus) are natives. The former carried plague in the Middle Ages, and the latter, invading less than three centuries ago, is a serious pest. Rabbits (Oryctolagus cuniculous) are an interesting story. Brought to England by the Normans in the 12th century, these were originally semidomesticated and were kept in specially designed warrens where they could be sheltered and fed, for they were a delicate species. Over the years, natural genetic selection resulted in a hardy race able to thrive in the cool, wet English climate and the descendants of escapees are incredibly common everywhere in the countryside, in spite of hunting pressures and periodic outbreaks of myxomatosis.

In an era where plants, animals and people move about the globe so easily, there will be many more of these unpleasant exchanges of species. At least the United States and Britain don't have to contend with cane toads, yet.

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