Loggerhead Shrike (Lanius ludovicianus)

Legal status in WI: endangered 1987 numbers in WI: less than 10 breeding pairs Length: 7-9 inches

Description

The loggerhead shrike is a masked, hook-billed songbird known for its habit of impaling prey on thorns or barbed wire. It is a gray, black and white bird, with a slim tail, large head, hooked black beak and distinctive black mask. When a shrike flies, you can see two white wing patches. Males and females are similar in size and color.

Because of its size, color and wing patches, the loggerhead shrike is easily confused with mockingbirds and more common northern shrikes. Mockingbirds, however, have longer tails, larger wing patches and no mask. Northern shrikes are slightly larger than loggerheads and have a barred breast, paler head, whiter rump and longer bill. Unlike the loggerhead's entirely black bill, the northern shrike's bill has a light-colored lower mandible.

The song of loggerhead shrikes is an often repeated medley of low warbles and harsh, squeaky notes and phrases. The bird's call is a harsh "shack-shack."

Comparison of Similar Species

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at the Comparison of similar species.

Food

Grasshoppers, beetles and other large insects are the main summer food of shrikes. In the fall and winter, mice and small birds make up more of their diet.

How does the shrike - a songbird that, unlike birds of prey, has weak feet, no talons and a small beak - capture and kill its prey? It drops onto prey from a perch or pursues the prey until it's tired, then hits and stuns it. The shrike quickly carries the prey in its bill to a thorn or piece of barbed wire and impales it. Once the prey is dead, the shrike tears away and eats small pieces with its sharp beak. The habit of impaling its prey has earned the shrike another name, "butcher bird."

Not all of what shrikes consume is digestible. The birds regurgitate hard insect parts, feathers and fur in pellet form.

Breeding Biology

By mid-spring, loggerhead shrikes return to Wisconsin from their wintering range in more southerly states. Individuals often return to the area where they nested the previous year, but may select a different mate.

The pair builds a nest 3-12 feet above the ground in the crotch of a tree branch. The nest is made of thick twigs and is lined with fine roots, fibers, mud, feathers and fur.

The female loggerhead lays an average of 6 light-yellow, dark-speckled eggs. She begins incubating once she lays the second-to-last egg and is fed by the male during the 16-day incubation period. Both parents feed the downy, buff-colored chicks. The chicks fledge when about 16 days old and stay with the adults another 3-4 weeks.

Distribution

The breeding range of loggerhead shrikes extends from southern Canada through the lower 48 states to southern Mexico. Virginia, southern Illinois and northern California form the northern edge of their winter range.

Loggerheads arrive in Wisconsin in late March or early April, and leave in September and October. An occasional bird may be seen during the winter. Northern shrikes are more common in the winter, however, and are easy to confuse with loggerheads. Northerns breed in the Canadian arctic and overwinter in the northern half of the U.S.

Within their range, shrikes prefer "edge" habitat, nesting along roadsides and hedgerows in agricultural regions. They prefer tree species with thorns (e.g., hawthorn, locust, crab apple, osage orange), on which they impale their prey.

Please click button for a map
of the distribution of Loggerhead Shrike.

A map outlining Pre-1977 and 1997 to Present Distribution is also available.

History In Wisconsin

Loggerhead shrikes once bred commonly in Wisconsin as far north as Douglas County. By the late 1960s, however, populations began declining and have never regained former levels. Causes of the decline are unknown, but increased use of pesticides is thought to be a main culprit. Pesticides have reduced the supply of insects, shrikes' main food, and have adversely affected the birds' reproductive physiology. The removal of farm fence rows has destroyed habitat where shrikes nest, also contributing to their decline.

Status

So few loggerhead shrikes remain in Wisconsin that they were placed on the Endangered Species List in 1979. Since 1980, observers have seen only 2-8 nesting pairs each year. These birds have nested in central and west central Wisconsin and in Door County.

Research and Management

Little research has been done on the status and biology of loggerhead shrikes in Wisconsin. The DNR Bureau of Endangered Resources (BER) is developing a shrike management plan. The plan recommends that biologists survey nesting sites, study habitat needs, examine eggs for contaminants, determine ways to protect and increase shrike populations and inform the public about shrike conservation work.

What You Can Do

The BER encourages you to participate in breeding bird surveys or informal birdwatching in your area and report any loggerhead shrike sightings to BER biologists at the address below.

You also can help by: maintaining farm and roadside hedgerows that provide habitat for shrikes and other wildlife; reducing your use of pesticides; supporting legislation banning especially harmful pesticides; and contributing to the Endangered Resources Fund on your Wisconsin income tax form.

Further Reading

Erdman, T.C. 1970.
Current migrant shrike status in Wisconsin.
Passenger Pigeon. 32(4):144-150.

Graber, R.R., J.W. Graber and E.L. Kirk. 1973.
Illinois Birds: Lanildae.
Biological Notes No. 83. 111. Nat. Hist. Survey. Dept. of Reg. and Educ. 18 pp.

Kumlien, L. and N. Hollister. 1951.
The Birds of Wisconsin.
Wisconsin Society of Ornithology. 122 pp.

Excerpt from THE ENDANGERED AND THREATENED VERTEBRATE SPECIES OF WISCONSIN

Status: State Endangered(1979).

Occurrence: Uncommon migrant and summer resident. Occasional winter visitor south and central. Summer range is generally south of a line extending from St. Croix County through Taylor County onto southern Marinette County and throughout Door County; occur occasionally in northern counties. A map outlining Pre-1977 and 1997 to Present Distribution is available.

Aid to ID: The loggerhead shrike is a little smaller than the American robin (Turdus migratorius) and has a gray back, light breast, black wings and tail, and light wing patches and tail bars. The large head has a black facial mask and a dark, heavy, hooked bill.

Habitat: Inhabit open grassy country with scattered shrubs or small trees.

Food Habits: Diet consists of a variety or prey including small mammals, birds, lizards, snakes, frogs and insects; especially grasshoppers, crickets and beetles. In winter, vertebrates are the most common prey, particularly small birds and mice. Loggerheads typically drop down onto prey from a perch.

Natural History:

Breeding: Clutch size: 4-7 (average of 6) dull white or buffy spotted eggs; laid from April to July. Incubation: 16 days, by both parents. Young fledge at 16 days.
Nest: Bulky, made of twigs, and lined with grasses, string, rootlets, feathers, and deer hair. in a variety of shrubs or trees 3-15 feet above the ground, hidden well below the crown of the shrub or tree.

Management Considerations: The population of loggerhead shrikes in Wisconsin has been declining since the late 1960's. The reason for this decline is not clear. There has been no significant change in this bird's preferred habitat or food supply, with the exception of the removal of farm fencerows, which reduced potential nesting habitat. A potential threat is pesticide contamination. Another concern is that the decline may be due to limiting factors in the wintering ranges, extending from southern Illinois as far south as central America.