If you've read my Foothill Agrarian blog over the last 12 months, you'll know I've been learning about (and, to some extent, writing about) the return of gray wolves to California and their potential impact on rangeland livestock producers. You'll also know that Flying Mule Farm has been committed to using nonlethal predator protection tools since we started raising sheep commercially more than 12 years ago. Our combination of livestock guardian dogs, electric fencing, and intensive grazing management has been highly effective at protecting our sheep from neighbor dogs, coyotes, mountain lions and black bears. The California Department of Fish and Wildlife believes that wolves will likely make it as far south as Interstate 80 in the Sierra Nevada - which suggests we might have wolves in our region in my lifetime. Because wolves are larger and (apparently) more intelligent carnivores - and mostly because I don't have any experience in dealing with them - this newly returned predator makes me worry that perhaps our current suite of nonlethal tools won't be sufficient.
According to the research I've read, and according to many of the nonprofit groups who support the wolves' return and who are trying to work with ranchers to find effective nonlethal protection tools, removing and disposing of livestock carcasses from rangeland and pasture settings can be one of the best ways to discourage wolves (and presumably other predators that are also scavengers - coyotes and bears, especially) from becoming habituated to killing and consuming livestock. Wolves are attracted to carcasses and even old bones. If these bone piles are in close proximity to grazing livestock, wolves may switch from carrion to killing.
I suppose I should explain a bit about typical livestock husbandry practices. Everyone I know who raises livestock on rangeland does it, at least in part, because they love working with animals and because they love the land. There are times in every ranching operation when animals die. We've lost ewes to old age, to injury, to snakebites, and to a number of unpreventable infirmities and diseases. If you have livestock, the saying goes, you'll also eventually have dead stock. Furthermore, my responsibility as a shepherd occasionally requires me to alleviate an animal's suffering by euthanizing it. I don't particularly like that part of my job, but I take this particular responsibility very seriously.
Once an animal has died, there are several options for disposing of the carcass. We can call a rendering company to retrieve the carcass. For sheep, this service runs $300-400 per animal (for an animal that might be worth as little as $30 at the auction). We can drive the carcass to UC Davis and deliver it to the California Animal Health and Food Safety laboratory. For $120 (for a sheep or goat), the lab will provide a complete necropsy report, which (usually) indicates the cause of death. We also get information about the animal's general nutritional and health status, which can help us improve our flock management. We typically use this service once or twice a year.
There are several things we can't do (at least in California). Legally, we can't bury a carcass on our owned or leased property. We also can't dispose of the carcass at most county landfills. And despite its demonstrated (in other states) efficacy and safety, composting is not currently an option in California (see this link on livestock composting for more information).
In addition to the economic considerations involved in carcass disposal, there are a number of logistical challenges involved. Even in our operation, we'll occasionally have an animal die at some distance from the closest road. While sheep are small compared to cattle, moving a sheep carcass without a vehicle or other equipment can be extremely challenging, to say the least. Imagine having to remove the carcass of a 2,000 pound bull that has died 10 miles from the nearest road in extremely rugged country. These challenges, at least to me, suggest that the "easy" solution of carcass removal as a nonlethal predator protection tool is easy on paper but (at times) incredibly difficult in practice. As a result, so-called "bone piles," which allow scavengers to do the work of carcass disposal, have often been the only viable option available.
These challenges suggest that we must do further research into effective composting techniques in California. Composting, if well-managed, can provide an alternative to producers while turning carcasses into a useful product. Other states have conducted such research; with the return of the gray wolf in California, perhaps it's time we start researching the topic here!