By Sheryl DeVore

n a cool December day last year, Gayle Wagner watched a northern shrike (Lanius excubitor) in McHenry County pluck what appeared to be a very frozen grasshopper impaled on a twig and chomp it down.

Last February, Tom Lally watched a shrike fly down to a small tree used as a caching site and yank the remains of some small mammal off a thorn and wolf it down.

Meanwhile Richard Biss was entertained while a shrike in his Lake Villa backyard in Lake County flew near a wetland, caught a vole, and ate it.

These experiences are rare for birders in the Chicago Wilderness region — the northern shrike only visits here in the winter from about October through March and its numbers are declining in eastern North America. These facts should give pause to observers who may not realize birds need not only good habitat for breeding, but also good wintering habitat. Indeed, says Steven D. Bailey, an ornithologist with the Illinois Natural History Survey, "most shrike species throughout the world are declining, for various reasons, some of which are still unknown."

Last winter, Illinois birders documented a record number of northern shrikes — 105 — and most were in the Chicago Wilderness region, says Bailey. But that doesn’t mean the species’ numbers are rising. National Christmas Bird Count data from 1900 through 1980 show northern shrikes go through irregular series of cycles. These fluctuations probably occur based on winter severity and prey availability on the shrike’s Canadian tundra breeding grounds.

Northern shrikes wintering here typically choose wet prairies and grassy areas near wetlands and lakes where tussocky grasses provide habitat for its favorite foods: voles, mice, and small birds. Some fairly reliable places to find northern shrikes annually include Illinois Beach State Park in Lake County, Fermilab in DuPage County, and Moraine Hills State Park in McHenry County.

The northern shrike defends large winter territories — as many as 540 acres. Like other members of its family, including the loggerhead shrike (a state threatened breeder in Illinois), the northern shrike catches it prey, then stores it in caches known as larders by impaling the prey on a sharp projection. "Hawthorns, crab apples, osage orange, and barbed wire are common sites for loggerhead shrikes in Illinois, and are likely sites for wintering northern shrikes as well," says Bailey.

The northern shrike is found here only in winter. The loggerhead shrike spends winters in the South but breeds regularly at Midewin National Tallgrass Prairie near Joliet.

Shrikes possess extremely acute vision. A trained shrike once spotted flying bumblebees at least 100 yards away. You may not get to experience shrikes catching bumblebees in Chicago Wilderness this winter, but if you choose the right habitat and wait patiently, you may spot a northern shrike perched atop a tree, scouting for prey. Be patient and keep your distance from this wary species because it often flies if approached too closely.