Wolves are getting a bad rap
Predatory wildlife being blamed for livestock deaths, but more die from disease and other factors
For example, The Vancouver Sun's Larry Pynn reports that last year the provincial government paid compensation to ranchers province-wide for 78 head verified as being killed by wild predators.
If the breakdown of livestock mortalities by predator species from 2009 - the most recent provincial analysis available - can be applied to 2010, then assume wolves killed 55 head across B.C.
B.C. Cattlemen's Association website cites a Statistics Canada report that there were 525,00 head of cattle on B.C. farms and ranches at the beginning of 2010. So 55 wolf-caused losses to B.C.'s total cattle herd would amount to slightly more than 0.01 per cent.
Last year, 45,000 beef cattle went to the abattoir for slaughter. En route, according to SPCA statistics, about 0.02 per cent normally die in transit or arrive so injured they must be euthanized.
In other words, truck transport from ranch to slaughterhouse is just about as serious a threat to livestock survival as wolves.
Meanwhile, a rancher from the Williams Lake area was charged following an SPCA investigation which found 40 of his cattle had starved to death and 130 were severely emaciated - that's about 0.03 per cent of B.C.'s cattle herd. Unfair to blame all ranchers for the behaviour of one individual, ranchers reasonably argue. Exactly. And it's equally unfair to blame wolves for livestock mortalities on the basis of unverified claims, anecdotal evidence and generalizations which arise from old prejudices.
The last time I wrote about this, ranchers complained that provincial statistics underestimated predator kills. In many cases, they said, ranchers didn't seek compensation for dead livestock because it was too difficult to satisfy provincial authorities that wolves had actually killed the animal. How did they know, then, that wolves were responsible? Well, they just knew, and you had to be a rancher to know, and if you weren't a rancher you shouldn't venture an opinion. Mind you, a press release from the B.C. Cattlemen's Association praising the arrest of a rustler acknowledged that many missing cattle which aren't reported may well have fallen victim to thieves not predators.
Furthermore, apparent predator kills can easily involve animals which died of other causes and were scavenged by wolves, bears or other animals.
How prevalent is death from other causes? Far more prevalent than predator kills, it seems. A benchmark study published in the journal of the Canadian Veterinary Association found that over the 17-year period examined, the annual death rate for cattle was consistently around 14 per thousand for older animals and 32 per thousand for calves.A subsequent study of mortality in beef cattle in western Canada, including B.C., published in the same journal, found that aside from slaughter, the predominant cause of death was disease. "Hardware disease (traumatic reticuloperitonitis), malignant neoplasia (cancer), calving-associated injury, rumen typany (bloat), mytopathy and pneumonia accounted for 56 per cent of the animals where a cause of death was determined," the researchers found. "Factors relating to cow nutrition accounted for 25 per cent of the deaths." The remaining mortalities were attributed to 23 other causes, of which predator deaths were a tiny proportion.
If the breakdown of livestock mortalities by predator species from 2009 - the most recent provincial analysis available - can be applied to 2010, then assume wolves killed 55 head across B.C.
B.C. Cattlemen's Association website cites a Statistics Canada report that there were 525,00 head of cattle on B.C. farms and ranches at the beginning of 2010. So 55 wolf-caused losses to B.C.'s total cattle herd would amount to slightly more than 0.01 per cent.
Last year, 45,000 beef cattle went to the abattoir for slaughter. En route, according to SPCA statistics, about 0.02 per cent normally die in transit or arrive so injured they must be euthanized.
In other words, truck transport from ranch to slaughterhouse is just about as serious a threat to livestock survival as wolves.
Meanwhile, a rancher from the Williams Lake area was charged following an SPCA investigation which found 40 of his cattle had starved to death and 130 were severely emaciated - that's about 0.03 per cent of B.C.'s cattle herd. Unfair to blame all ranchers for the behaviour of one individual, ranchers reasonably argue. Exactly. And it's equally unfair to blame wolves for livestock mortalities on the basis of unverified claims, anecdotal evidence and generalizations which arise from old prejudices.
The last time I wrote about this, ranchers complained that provincial statistics underestimated predator kills. In many cases, they said, ranchers didn't seek compensation for dead livestock because it was too difficult to satisfy provincial authorities that wolves had actually killed the animal. How did they know, then, that wolves were responsible? Well, they just knew, and you had to be a rancher to know, and if you weren't a rancher you shouldn't venture an opinion. Mind you, a press release from the B.C. Cattlemen's Association praising the arrest of a rustler acknowledged that many missing cattle which aren't reported may well have fallen victim to thieves not predators.
Furthermore, apparent predator kills can easily involve animals which died of other causes and were scavenged by wolves, bears or other animals.
How prevalent is death from other causes? Far more prevalent than predator kills, it seems. A benchmark study published in the journal of the Canadian Veterinary Association found that over the 17-year period examined, the annual death rate for cattle was consistently around 14 per thousand for older animals and 32 per thousand for calves.A subsequent study of mortality in beef cattle in western Canada, including B.C., published in the same journal, found that aside from slaughter, the predominant cause of death was disease. "Hardware disease (traumatic reticuloperitonitis), malignant neoplasia (cancer), calving-associated injury, rumen typany (bloat), mytopathy and pneumonia accounted for 56 per cent of the animals where a cause of death was determined," the researchers found. "Factors relating to cow nutrition accounted for 25 per cent of the deaths." The remaining mortalities were attributed to 23 other causes, of which predator deaths were a tiny proportion.
The Canadian research echoes American science. A study of livestock mortality which covered 87 per cent of the U.S. beef herd in 2007 and 2008 found that more than one half of the deaths of calves were caused by digestive and respiratory ailments, weather killed another 10 per cent and only 4.7 per cent fell victim to predators.
So, what the veterinary science tells us is that better than 80 per cent of livestock mortalities are caused by disease or nutrition issues. Government records tell us that the rate of mortality for beef cattle dying in transit is about the same as the rate of wolf killings. But the anti-wolf lobby claims on hearsay and folklore that wolves are to blame for excessive livestock mortalities.
If this were a court case, it would be dismissed as not proven. B.C.'s wolves deserve a reprieve unless those backing a wolf slaughter can provide credible and verifiable evidence justifying it.
So, what the veterinary science tells us is that better than 80 per cent of livestock mortalities are caused by disease or nutrition issues. Government records tell us that the rate of mortality for beef cattle dying in transit is about the same as the rate of wolf killings. But the anti-wolf lobby claims on hearsay and folklore that wolves are to blame for excessive livestock mortalities.
If this were a court case, it would be dismissed as not proven. B.C.'s wolves deserve a reprieve unless those backing a wolf slaughter can provide credible and verifiable evidence justifying it.
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