Sentences with phrase «estimated number of birds»

In his paper, «Estimated Number of Birds Killed by House Cats in Canada,» Peter Blancher used a variety of research to determine that somewhere between 40 to 70 % of Canadian house cats are allowed to free - roam outdoors.

Dr Conor O'Gorman, BASC's policy development manager, said: «The UK section of the report is short on facts, estimating the number of birds illegally killed in the UK as anywhere from 300 to 14,500.

It's part of a three - year Fish and Wildlife Service - funded effort to estimate the number of birds killed by predators, chemicals and in collisions with wind generators and windows.

Not exact matches

So researchers turned to two different estimation methods — one whereby total mortalities were estimated from the actual number of dead birds recovered, and another in which information on the geographic extent of the oil slick and seabird densities were used to estimate potential mortalities.

Energy company BP faces civil penalties based in part on the number of birds and other wildlife lost in the spill, therefore the mortality estimates could influence the amount the company will be required to pay.

Researchers estimated bird and deer numbers at two regions of Virginia — one on the coast and one inland.

They estimate that a carefully prepared 5 % increase in conservation area would allow a dramatically improved capture of bird and mammal biodiversity facets; an approach focused on species numbers alone would be much less optimal, the researchers said.

While the impact of one domesticated cat doesn't seem that much, it is estimated that cats kill hundreds of millions of birds every year with feral cats only killing 20 % of that number.

Higgins relies on Dauphiné and Cooper for estimates of both the number of «stray and out - and - out feral cats» («there may be as many as 100 million such cats in the country») and birds killed by free - roaming cats («at least one billion birds are killed by cats annually, «and the actual number is probably much higher.

Biologists also have used the studies from Marra, Temple, and a number of others to estimate the total U.S. death toll for birds due to cat predation as more than a billion per year.

``... the ecological and conservation significance of these kill tallies is difficult to contextualise, because (1) there are no reliable estimates of the total population of birds in Australia; (2) predation may fall disproportionately on some bird species; (3) some bird species may be able to sustain high mortality rates and maintain viable populations but others may not; and (4) as demonstrated here, there is substantial spatial variation in the numbers and proportion of birds killed across Australia.»

In addition to posing a rabies risk, outdoor and feral cats that number at least 95 million animals in the United States, are responsible for killing an estimated 500 million birds annually in addition to scores of other small animals.

«This was clearly not realistic, as the estimated maximum numbers of birds killed typically exceeded breeding density and productivity combined, such that the prey populations studied would probably have gone extinct rapidly at a local level or acted as a major sink for birds immigrating from neighbouring areas.»

The study estimated that the median number of birds killed by cats annually is 2.4 billion and the median number of mammals killed is 12.3 billion.

There was, of course, witch - hunt pioneer Stan Temple's op - ed in the Sun - Sentinel, referring to the paper as «a new study... provid [ing] a science - based estimate of the number of birds and mammals killed by cats nationwide.»

As the numbers of cats declined, the last having been killed in 2000, the rabbit population increased, to an estimated 100,000 by 2007 ---- and rabbit damage to bird nesting habitat proved far more damaging to the sea bird population than cat predation ever had been.

Exact numbers are unknown, but some experts estimate that each year domestic and feral cats kill hundreds of millions of birds, and more than a billion small mammals, such as rabbits, squirrels, and chipmunks.

The Condor has nominated Andrew Dennhardt, lead author of the paper Applying citizen - science data and mark — recapture models to estimate numbers of migrant Golden Eagles in an Important Bird Area in eastern North America (press release).