Sentences with phrase «predation rates by»

Data on predation rates by pet cats in Canada would also be very helpful.»

Cats and Birds As evidence of the «variable predation rates by cats,» [2] The ABC Guide refers to just four studies.

Hunters and non-hunters: skewed predation rate by domestic cats in a rural village.

where npc is the number of owned cats in the contiguous United States, pod is the proportion of owned cats granted outdoor access, pph is the proportion of outdoor owned cats that hunt wildlife, ppr is the annual predation rate by owned cats, cor is a correction factor to account for owned cats not returning all prey to owners, nfc is the number of un-owned cats in the contiguous United States, pfh is the proportion of un-owned cats that hunt wildlife, and fpr is the annual predation rate by un-owned cats.

Not exact matches

«You can argue that the animals that are affected by rodenticide are weaker,» Thompson says, «and that the predation rates on them, as I suspect, are higher.»

During the same period, predation rates — the proportion of the moose population killed by wolves — also dropped to the lowest ever recorded, while the number of moose doubled, to approximately 1,050 moose.

The ASN Presidential Award for the paper that best fulfills the goals of the ASN in the American Naturalist during 2015 is «The Evolution of Foraging Rate across Local and Geographic Gradients in Predation Risk and Competition» by Mark C. Urban and Jonathan L. Richardson

Higher metabolic and survival costs induced by predation risk were only partially offset by changes in consumption rates and assimilation efficiencies and the magnitude of non-consumptive effects varied as a function of temperature.

A related concept, the mesopredator release hypothesis, predicts that the removal of apex predators leads to the irruption of mesopredators with concomitant declines in the abundances of their prey owing to elevated rates of predation by mesopredators [10].

Overall, when wearing the Birdbesafe collar, rates of identified predation reduced by a total of 37 %.

We modelled the potential threats to the northern bettong and determined that predation by feral cats has the highest potential to cause bettong population declines, with juvenile mortality rates impacting bettong population stability more than adult mortality.

This study by Environment Canada scientist Peter Blancher was designed to create a credible estimate of the rates of bird predation by cats, identify information...

In other words, no difference between predation rates predicted by actual hunting observation and those predicted by way of prey returned home.

More recently, Dauphiné and Cooper use the inflated predation rate suggested by Lepczyk et al. (along with rates proposed by other researchers) to arrive at their «billion birds» figure.

«In Illinois, George (1974) found that only about half of animals killed by cats were provided to their owners, and in upstate New York, Kays and DeWan (2004) found that observed cat predation rates were 3.3 times higher than predation rates measured through prey returns to owners.

Barratt has shown that the actual predation rate, at this level, is less than half the rate predicted by cat owners.

The two studies can not be compared directly for a number of reasons, but by way of comparison, the average predation rate used by Lepczyk et al. is approximately 31 birds / cat for the 22 - week breeding season.

So, whereas Dauphiné and Cooper (and others) suggest increasing such estimates by factors of two and three («predation rates measured through prey returns may represent one half to less than one third of what pet cats actually kill...» [14]-RRB-, they should, in fact, be reducing them by half.

This greatly overestimates potential predation, and leads them to conclude — erroneously — that the actual number of prey killed by cats was «3.3 times greater than the rate estimated from prey brought home,» [9] as was discussed previously.

In their recently released book, The American Bird Conservancy Guide to Bird Conservation, ABC changes tack a bit — using what the authors call «conservative» estimates of the outdoor cat population and annual predation rates, for example, to arrive at their figure of «532 million birds killed annually by outdoor cats.»

Without site fidelity by predators, therefore, predation rates averaged across space and over time can be higher9.

We excluded studies from outside temperate regions and those with predation rate estimates based on fewer than 10 cats, < 1 month of sampling, or on cats that were experimentally manipulated (for example, by fitting them with bells or behaviour altering bibs).

Mean predation rates within each square each season were multiplied by cat density to estimate the total number killed, and summed across seasons to estimate the number killed annually.

The California Gray Whale Coalition can find no evidence to suggest that the US Government takes into account the very high mortality rates caused by Orca predation.