Wednesday, May 22, 2019

Lewis’s Woodpeckers are Thriving in Western Montana

Lewis’s Woodpeckers are an exciting western species that is uncommonly encountered, unless you’re in the riparian bottomlands of western Montana.

Researchers are studying a thriving population of Lewis’s Woodpeckers that nest along the riparian bottomlands of the Bitterroot and Clark Fork Rivers in western Montana near Missoula. That’s exciting news, especially considering this species is declining across much of its western range. While studying about 55 active nest sites to date, Megan Fylling with the University of Montana Bird Ecology Lab, has found a common thread among the nest sites selected by Lewis’s Woodpeckers.

“They prefer old stands of black cottonwood trees mixed with some open areas along the river bottomlands,” Megan explained. “Their nest sites have been cavities excavated in old dead or mostly dead trees.”

But a somewhat unexpected behavioral insight for a species of woodpecker is that Lewis’s Woodpeckers aren’t big excavators. Megan pointed out that the Lewis’s she’s observed preferred to use existing cavities, adding some personal modifications to the cavity they choose each spring. She added that the area hosts a variety of other woodpeckers that excavate cavities, including Pileated and Hairy Woodpeckers, Red-naped Sapsuckers, and Northern Flickers.

Fylling explained that most of the cavities that Lewis’s Woodpeckers select have been in dead or partly dead black cottonwoods, although some pairs have also utilized dead or dying ponderosa pines. The nest sites are also characterized by their proximity to open areas in the woodland that provide foraging areas.

Rather than excavating wood for insects like Pileated Woodpeckers or digging for ants on the ground like Northern Flickers, Lewis’s Woodpeckers most often feed in a flycatching fashion. That is, they perch high in a tree adjacent to an open area, then fly out to catch flying insects on the wing, returning to a perch to feed, then repeating the process – moving from location to location as the localized abundance of flying bugs dictates.

The nesting biology of Lewis’s Woodpeckers has not been widely studied to date, so the on-going studies with the aid of Montana Audubon volunteers, are adding new information about this interesting species. Megan’s colleagues, William Blake and Kate Stone at the MPG Ranch, are studying nesting success rates; and some team members are even monitoring where the birds winter, including mapping their migration routes. It’s a comprehensive look at a successful population of a woodpecker species that is uncommon and declining in other areas, with the hope that information gleaned in Montana will help land managers improve riparian habitats for Lewis’s Woodpeckers in other states.

Megan’s long-range interest is to be sure that the dead trees, branches, and snags that Lewis’s Woodpeckers and other species rely on for nesting sites are appreciated and protected in riparian areas. In some spots, housing developments may change such important habitat elements, but it seems the Lewis’s are faring well in some open suburban areas.

“We really need to look decades ahead to be sure that black cottonwood stands are renewed by younger trees that will eventually become the old growth favored by nesting Lewis’s Woodpeckers,” Fylling added. Megan is especially enthusiastic about starting this field season and looking deeper into the world of Lewis’s Woodpeckers.

For more information about this Lewis’s Woodpecker project and other work conducted by the University of Montana Bird Ecology Lab, seehttp://hs.umt.edu/birdecologylab/stories-folder/default.php