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Loggerhead Shrike (Lanius ludovicianus), listed as Endangered in Wisconsin, prefers open country with scattered trees and shrubs (usually hawthorne and red cedar), and edge habitat such as open areas in forests. The required avoidance period is April 20 - August 1.
The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for Loggerhead Shrike (Lanius ludovicianus). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where occurrences of this species meet NHI data standards and is not meant as a comprehensive map of all observations.
Note: Species recently added to the NHI Working List may temporarily have blank occurrence maps.
Summary Information | |
---|---|
State Status | END |
Federal Status in Wisconsin | SOC |
State Rank | S1B |
Global Rank | G4 |
Tracked by NHI | Y |
WWAP | SGCN |
Identification: The Loggerhead Shrike is a songbird known for its habit of impaling prey on thorns or barbed wire. It is has a gray back, black wings, light colored breast and a slim, black 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.
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".
Similar Species: 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.
Habitat: They inhabit open, grassy country with scattered shrubs or small trees. 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.
State Distribution: Summer range is generally south of a line extending from St. Croix County through Taylor County onto southern Marinette County and throughout Door County; sometimes occur in northern counties. An occasional bird may be seen during the winter in south and central Wisonsin. Northern Shrikes are more common in the winter, however, and are easy to confuse with loggerheads.
Global 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.
Rationale for Species Listing and Threats: 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. Habitat has not been significantly altered other than the removal of farm fence rows, which has destroyed habitat where shrikes nest, also contributing to their decline. 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.
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.
Phenology: Loggerheads arrive in Wisconsin in late March or early April, and leave in September and October.
Diet: Grasshoppers, beetles, crickets 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. Diet may also include snakes, lizards and frogs.
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.
Life and Natural History: 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 3-15' above the ground in a shrub or the crotch of a tree branch, hidden well below the crown of the vegetation. The bulky nest is made of thick twigs and is lined with fine roots, grasses, fibers, mud, feathers, and fur.
The female Loggerhead lays an average of 6 light-yellow, dark-speckled eggs between April and July. Incubation begins once the second-to-last egg is laid 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.
Management Guidelines: Little research has been done on the status and biology of Loggerhead Shrikes in Wisconsin. The Wisconsin recovery plan (1988) 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.
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The table below lists the natural communities that are associated with Loggerhead Shrike. Only natural communities for which Loggerhead Shrike is "high" (score=3) or "moderate" (score=2) associated are shown. See the key to association scores for complete definitions. Please see the Wildlife Action Plan to learn how this information was developed.
Natural community | Score |
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Surrogate Grasslands | 3 |
Dry Prairie | 2 |
Dry-mesic Prairie | 2 |
Oak Barrens | 2 |
Sand Prairie | 2 |
The table below lists the ecological landscape association scores for Loggerhead Shrike. The scores correspond to the map (3=High, 2=Moderate, 1=Low, 0=None). For more information, please see the Wildlife Action Plan.
Ecological priorities are the combinations of natural communities and ecological landscapes that provide Wisconsin's best opportunities to conserve important habitats for a given Species of Greatest Conservation Need. The 10 highest scoring combinations are considered ecological priorities and are listed below. More than 10 combinations are listed if multiple combinations tied for 10th place. For more information, please see the Wildlife Action Plan.
* Ecological priority score is a relative measure that is not meant for comparison between species. This score does not consider socio-economical factors that may dictate protection and/or management priorities differently than those determined solely by ecological analysis. Further, a low ecological priority score does not imply that management or preservation should not occur on a site if there are important reasons for doing so locally.
Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the WWAP because lack of information can threaten our ability to successfully preserve and care for natural resources.