TIME: Almanac 1990/1990 Time Magazine Compact Almanac, The (1991)(Time).iso/time/073189/07318900.003

Text File | 1990-09-17 | 4KB | 70 lines

ENVIRONMENT, Page 46

Attack of the Killer Cats

A study shows that those lovable furry pets decimate wildlife


    While fond of his cat, British biologist Peter Churcher looked
askance at its practice of dragging small mammals and birds into
his Bedfordshire house and devouring them under the kitchen table
"to the sound of crunching bones." One of Churcher's associates,
John Lawton, a professor of community ecology at the University of
London, was similarly impressed by his own cat's predatory
pursuits. With the natural curiosity of true scientists, they
decided to look further into the depredations of felines. If all
the domestic cats in Britain caught as much prey as theirs did,
the two men reasoned, they could be having a "very significant"
impact on the environment.

    Hyperbole? Not at all. Writing in the July issue of Natural
History, Churcher and Lawton estimate that Britain's 5 million
house cats wreak an annual toll of some 70 million animals and
birds.

    In reaching this astonishing conclusion, the intrepid
investigators used only the most rigorous scientific methods.
Choosing Churcher's small village as their test site, they
conducted a feline census and found that 78 cats resided in the
community's 173 houses, "a slightly higher incidence of cat owning
than in Britain as a whole." Owners of 77 of the cats agreed to
cooperate. Each was given a supply of consecutively numbered
polyethylene bags labeled with his cat's code letter and asked to
store whatever was left of any prey his pet brought home.

    For a full year the scientists made weekly rounds of the
village, collecting bags and identifying the remains. If the cat
had consumed the entire catch, the victim was simply recorded as
an "unknown." Otherwise, the identification process was simple, the
scientists report, although "initially -- the study began during
the summer months -- it was rather smelly." Surprisingly enough,
they write, "the villagers were much less squeamish than we had
expected." In fact, some went about their assigned task with great
gusto, placing their cats' trophies in home freezers to await
collection.

    Tallying and analyzing their data at the end of a year, the
investigators found that the cats had claimed almost 1,100 items
of prey, 64% consisting of small mammals: mostly wood mice, field
voles and common shrews, interspersed with an occasional rabbit,
weasel or pipistrelle bat. The remaining victims, all birds,
included sparrows, song thrushes, blackbirds and robins.

    Delving further into the sparrow toll, which accounted for 16%
of the total feline catch, the scientists concluded that from a
third to a half of all sparrow deaths were attributable to cats.
Extrapolating these figures, they estimated that cats kill at least
20 million birds a year in Britain. "Yet," write the authors
indignantly, "we are supposed to be a nation of bird lovers, many
of whom keep cats but still castigate bird hunters and trappers on
the continent of Europe."

    Impressive as these statistics are, the scientists note, the
carnage may be even worse. They cite an American study indicating
that house cats bring only about half their victims home.

    Will cat fanciers find these conclusions unsettling? Evidently
not. When the authors' work was published earlier in a scientific
journal, including the fact that a few Bedfordshire cats had each
contributed as many as 100 items of prey to the study, they
received letters from other cat owners boasting of their own pets'
prowess. The record, they report, is currently held by a cat from
Dorset that dragged in more than 400 little creatures in one year.
The scientists are aghast. "These proud owners," they report, "seem
quite unperturbed by the slaughter."