Nature provides many ways to keep life interesting for its followers.
Erika Peckham experienced first-hand the way nature makes life interesting when she focused her spotting scope on a male sage grouse/sharp-tailed grouse hybrid in northern Crook County. She was monitoring a sage grouse lek, or courtship ground, early the morning of May 10.
“I knew immediately I was looking at something pretty unusual,” said Peckham, Wyoming Game and Fish Department wildlife biologist. “It exhibited physical attributes and courtship behaviors of both species, but it didn’t represent either species very well.”
The bird’s head looked a lot like a sharp-tailed grouse, but the tail displayed traits of both species. The hybrid had an inflated chest similar to a sage grouse; however it was dark brown opposed to the trademark white of a sage grouse.
Both native species inhabit the area, along with many other areas of eastern Wyoming and some of the sagebrush area northeast of Baggs in south-central Wyoming. The most recent, and only other official, sighting of this hybrid in Wyoming was in Sheridan County in March 1979.
Peckham was alerted to another unusual grouse occurrence by the rancher who hosts the lek in his pasture. In late summer 2011, the rancher told Peckham there was a sage grouse roosting with the resident flock of sharptails in the shelterbelt around his home. He took Peckham to investigate. From what she saw as the bird flushed and flew off, the Gillette biologist agreed that the bird in question looked like a sage grouse.
“I certainly can’t say that the bird at the ranch was the same bird on the lek or had anything to do with it – but it makes you wonder with the sightings being only 5 miles apart,” she said. “In my years spent working with sage grouse I have never seen them roost in trees. If nothing else, it further illustrates that there is a certain amount of interspecies contact occurring in this area.”
Sage grouse/sharp-tailed hybrids are uncommon. The most recent documented sighting was in May 2012 in southwest North Dakota. A specimen collected in the same county in 1984 was donated to the Smithsonian Institution. The Smithsonian discovered the rooster’s sex organs were undersized and the bird was likely sterile.
“This is to be expected,” Peckham said. “Nature has a built-in mechanism for taking care of occurrences like this. The offspring of an inter-species mating are oftentimes sterile.”
South Dakota documented a hybrid in 2008 and two hybrids were observed in southeast Alberta in both 1999 and 2000. The Alberta hybrids were captured and DNA analysis showed they were the offspring of sharp-tailed sires and sage grouse mothers.
In May, Peckham and the rancher witnessed the hybrid rooster chase a male sage grouse off the lek and act considerably more aggressive than the sage grouse – but the hybrid was not seen in the act of breeding.
The most common hybridization in game birds is probably wild mallards with other ducks – wild and domestic.Whitetail-mule deer crosses are fairly common, with estimates as high as 3 percent in areas where the species overlap. Other grouse hybrids, including blue/sage, sharp-tailed/prairie chicken, ruffed/sharp-tailed and ruffed/spruce have also been documented in North America. Ring-necked pheasant/blue grouse and pheasant/prairie chicken hybrids have also been documented.
Peckham appreciates the wildlife management help she gets from landowners in the area. “In northeast Wyoming, which is predominantly private land, I have had the opportunity to meet and work with some great landowners who have allowed access to their ranches,” she said. “Without their willingness to work with Wyoming Game and Fish we would miss out on documenting things, like this hybrid grouse.”