c**i
发帖数: 6973 | 1 Elisabeth Rosenthal, Twitty Was Right: Cats Are a Bird's No 1 Enemy. New
York Times, Mar 21, 2011.
http://www.nytimes.com/2011/03/21/science
/21birds.html?_r=1&scp=1&sq=cat%20bird&st=cse
Quote:
"Nearly 80 percent of the birds were killed by predators, and cats were
responsible for 47 percent of those deaths
"The American Bird Conservancy estimates that up to 500 million birds are
killed each year by cats — about half by pets and half by feral felines. *
* * By contrast, 440,000 birds are killed by wind turbines each year,
according to the United States Fish and Wildlife Service, although that
number is expected to exceed one million by 2030 as the number of wind farms
grows to meet increased demand.
My comment:
(a) Tweety
http://en.wikipedia.org/wiki/Tweety
(a fictional Yellow Canary; in the Warner Bros. Looney Tunes and Merrie
Melodies series; The name "Tweety" is a play on words, as it originally
meant "sweetie", along with "tweet" being a typical English onomatopoeia for
the sounds of birds./ Despite the perceptions that people may hold, owing
to the long lashes and high pitched voice of Tweety, Tweety is male; created
in 1942)
(b) catbird
http://en.wikipedia.org/wiki/Catbird
(Several unrelated groups of songbirds are called catbirds because of their
wailing calls, which resemble a cat's meowing)
(c) After reading quotation 1, I wondered how many bird deaths were
attributed to glass. Here is what the study finds:
"During our study of post-fledging survival, 61% (42/69) of individuals died
before reaching independence. Predation on juveniles accounted for 79% (33/
42) of all mortalities (Bethesda 75% (6/8), Spring Park 75% (12/16), and
Opal Daniels 83% (15/18) with the vast majority (70%) occurring in the first
week post-fledging. Directly observed predation events involved domestic
cats (n = 6; 18%), a black rat snake (n = 1; 3%), and a red-shouldered hawk
(n = 1; 3%). Although not all mortalities could be clearly assigned,
fledglings found with body damage or missing heads were considered
symptomatic of cat kills (n = 3; 9%), those found cached underground of rat
or chipmunk predation (n = 7; 21%) and those found in trees of avian
predation (n = 1; 3%). The remaining mortalities (n = 14; 43%) could not be
assigned to a specific predator. Mortality due to reasons other than
predation (21%) included unknown cause (n = 2; 22%), weather related (n = 2;
22%), window strikes (n = 2; 22%) and individuals found close to the
potential nest with no body damage (n = 3; 34%), suggesting premature
fledging, disease or starvation.
(d) An African American family took me in as their son. They kept a cat in
their rural home, which was declawed at an early age. Somehow the cat would
bring dead birds back home, to the bewilderment of the family: How does he
catch birds without claws? |
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