Wolves kill to fill their stomachs or reduce competition, and the Yellowstone Wolf Project keeps tabs on fatalities from both causes. The project sends teams by land or air to study specific Yellowstone wolf packs. These technicians may see a kill occur or investigate the remains. Other technicians hike, ski, or snowshoe to where the project suspects a carcass. And there's that army of wolf watchers glued to spotting scopes. All in all, Yellowstone's wolves may be the most observed in the world.
The project summarizes the findings from sources such as these in its annual reports. After spending hours studying all the reports from 1996 to the most recent, I picture a wolf menu with entrees more varied than I imagined. Here's what I would list on the menu under "big meals":
The preferred meal. On average, each Yellowstone wolf consumed two and one-half elk each year since 1995. But some years are better than others. In 2008 - a banner year - the average wolf feasted on almost four elk. In 2004 that average wolf rationed a meager one and one-half.
These are mainly a specialty menu item for wolves in Yellowstone's interior. One pack in particular, the Mollie's, makes its living bringing down these feisty giants.
Much smaller than elk, one deer isn't a feast for a wolf pack. But as the number of elk on the Northern Range (Yellowstone's northeast corner) has fallen, the number of deer consumed has risen.
Though a big meal, wolves have only consumed 54 since 1995. I imagine that bringing down a large animal with hefty hooves and awesome antlers is not inviting.
Pronghorn, Bighorn, Mountain goats
Built for speed, pronghorn can out run wolves, and wolves have brought down only 29 since 1995, most likely calves or ailing older animals. Bighorns and mountain goats tend to hang on cliffs where hungry wolves are at a distinct disadvantage.
The Wolf Project records other animals wolves consume. Most are so small that I would list them on the menu under "starters." These include beaver, badger, rabbit, otter, skunk, porcupine, weasel, grouse, and even one owl killed in 1999.
The project also lists competitors killed - and usually not eaten - by wolves. Coyotes top that list with 88 eliminated since wolves returned. Though one researcher watched a wolf pack attack a coyote den and kill pups, most coyotes die while scavenging wolf kills.
Wolves hold second place on the competitor list with 76 killed since 1995. Wolves battle one another to defend territory or a meal. Interestingly, wolves killed only three of their own between 1995 and 2001. But as the number of elk on the Northern Range fell, the number of wolves killed by wolves increased.
The red fox also made the competitor list - five have died at the teeth of wolves since 1995. Wolves have eliminated a smattering of other competing predators including cougars, black bears, grizzly bears, and grizzly cubs.
Rick Lamplugh is a wolf advocate and author of the bestselling "In the Temple of Wolves." Available as eBook or paperback at http://amzn.to/Jpea9Q. Or as a signed copy from the author at http://bit.ly/1gYghB4.
(Top photo: Wolves chasing elk.)