Home & Garden Columns
I’ve avoided wild turkeys as a subject since that unpleasant business with the Sierra Club a couple of years ago, when I caught hell for writing that the environmental impact of these introduced birds had not yet been documented. Now, finally, there’s a study, published last year in the journal Western Birds, entitled “Food Habits of the Wild Turkeys in National Forests of Northern California and Central Oregon.”Does it shed badly needed light on the controversy? Well, sort of.
The case against the turkey seems to have two main arguments. First, wild turkeys are aliens; the ones in California are primarily Rio Grande and Merriam’s turkeys from the Southwest. Thus they’re a new, and unpredictable, element in our ecosystems, and might outcompete native birds like the California quail. (However, a very similar species was present in Southern California until about 11,500 years ago, and a couple of prehistoric turkey bones have been found in caves in Northern California.)
Second, wild turkeys are omnivores. Back east, they’re known to eat a lot of acorns and the occasional lizard or salamander. Concern has been expressed about turkey predation on vulnerable species, although I don’t know whether they’ve ever been caught in the act. If a turkey happened to consume a newt, a highly toxic amphibian, that would be one less turkey.
I have a suspicion that a lot of the anti-turkey animus comes from the fact that these are large, loud, untidy birds that sometimes become aggressive with people. Also, their presence makes turkey hunters happy. These are not major themes in the public discourse, though.
So here’s the Western Birds article, whose authors spent three years collecting, classifying, and analyzing over 400 turkey droppings in the El Dorado, Modoc, Plumas, Tahoe, and Mendocino National Forests, plus two national forests in Oregon. The feces of tom and hen turkeys, it seems, are visibly distinct, so it was possible to categorize the diets of both sexes. Plant remains in the droppings were identified to species where possible.
The turkeys were found to have been eating variable proportions of plants and insects. Plants were broken down into grasses, sedges, forbs (herbaceous flowering plants), coniferous trees, shrubs, seeds, roots, ferns, and agricultural grains. Acorns were apparently subsumed under seeds. The birds consumed more seeds and flowers than stems, roots, and leaves. Grass consumption ranged from 1.3 percent among spring males in the Modoc National Forest to 66.8 percent for summer males in the Plumas National Forest. Females in Oregon’s Deschutes National Forest favored conifer seeds in spring. In the Modoc, 95.8 percent of the spring males had been eating forbs.
In California, hens ate a higher proportion of insects than toms.
This may indirectly reflect the dependence of young turkeys on insects, since females have to show the poults what’s edible and what’s not. The difference between the sexes did not show up in the Oregon sample.
No small vertebrates were reported, though. Are the turkeys off the hook?Maybe, maybe not.The way the data are presented, you can’t really conclude that none were found. It’s also curious that acorns weren’t analyzed as a separate category.
There’s also a credibility issue. Two of the authors of the article are contract biologists with MGW Biological Surveys in McKinleyville. Contract biologists are a mixed bag; I don’t know about MGW, but some have acquired the reputation of finding what their clients want them to find. The other two are affiliated with the National Wild Turkey Federation, a turkey hunters’ interest group. These folks have conducted other research projects which (surprise!) absolve turkeys of wrong-doing. One found that turkeys are blamed for more damage to vineyards than they actually cause.
The NWTF’s web site (www.nwtf.org) is worth a visit. Its on-line Turkey Shoppe offers all kinds of turkey wearables, collectibles, and paraphernalia, including turkey-track ties, turkey trailer hitch covers, and a beard rack. A beard rack is where you display the hairlike chest plumes of trophy-rank tom turkeys. If you’ve seen Errol Morris’s early film “Vernon, Florida,” you’ll be familiar with the concept.
I am not bashing turkey hunters. But, I suspect that like most hunters they’re primarily interested in maintaining a good-sized population of their favorite huntable critter, with other environmental considerations taking a back seat. That’s why elk hunters in the Rockies have lobbied to eradicate wolves; why hunters in Hawai’i have blocked efforts to remove feral pigs and goats from remnant native forests.
In short, these are not the people you’d go to for an impartial assessment of how wild turkeys are affecting their environment.
It’s like relying on Monsanto to evaluation the impact of genetically modified crops, or on BP to…you get the idea.
I don’t know whether Western Birds is peer-reviewed, but perhaps its editors should have thought twice about accepting the article.
We’re still waiting to hear from scientists who don’t have a dog, or a turkey, in this fight.