Loggerhead Shrike migrans subspecies
Scientific Name: Lanius ludovicianus migrans
Other/Previous Names: Eastern Loggerhead Shrike,Loggerhead Shrike (Eastern population)
Taxonomy Group: Birds
COSEWIC Range: Manitoba, Ontario, Quebec
COSEWIC Assessment Date and Status Change: May 2014
COSEWIC Status: Non-active
COSEWIC Status Criteria:
COSEWIC Reason for Designation:
COSEWIC History of Status Designation: The species was considered a single unit and designated Threatened in April 1986. Split according to subspecies in April 1991. The migrans subspecies was designated Endangered in April 1991. Status re-examined and confirmed in November 2000. De-activated in May 2014 in recognition of new genetic information indicating that some of the individuals in southeastern Manitoba should not have been included in the migrans subspecies.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2003-06-05
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
|Loggerhead Shrike Eastern subspecies||Endangered||No Status|
Image of Loggerhead Shrike migrans subspecies
The Loggerhead Shrike migrans subspecies is commonly called “Eastern Loggerhead Shrike”.
The Loggerhead Shrike, a songbird measuring approximately 21 cm in length, is slightly smaller than a robin. This bird’s most striking feature is its broad black facial mask, which covers its eyes entirely. The mask extends above the eyes, where it is crowned by a narrow white strip and forms a thin line just above the base of the bill. Males and females are similar in appearance. With their contrasting black, white and grey plumage, adults are particularly conspicuous in flight. The top of the head, the back and the hind quarters are dark grey, while the lower body is whitish with barely visible stripes. The wings and long tail are mostly black and a clearly visible white line separates the back from the wings. Juveniles have a brownish plumage with greyish striping on the chest and belly. Like birds of prey such as falcons or hawks, Loggerhead Shrikes have a hooked bill, which is black in colour. The Loggerhead Shrike is an ambush predator that perches in treetops and on wires. This species is known for its habit of impaling its prey on thorns or barbed wire. The call is a combination of melodious and harsh notes. This bird is easily confused with the Northern Shrike, a highly similar related species. The Northern Shrike is slightly bigger (approximate length of 25 cm) and the base of its bill, which is longer and more curved, is slightly lighter. In addition, its facial mask does not extend above the eyes or to the top of the bill, and the striping on its chest is more conspicuous.
Distribution and Population
The range of the migrans subspecies once extended from southeastern Manitoba and northwestern Ontario to New Brunswick, and southward to northeastern Texas, the western part of North Carolina and Maryland in the United States. In the 1990s, the shrike populations in northwestern United States and Canada underwent a continuing decline. Distribution of the species in the south is unchanged, but this bird has virtually disappeared from most of the central and northern regions of its former range. The Canadian population is basically isolated from the larger populations found in the south-central United States. This is a migrating species that leaves northern habitats and heads south towards the eastern United States. In Canada, the migrans subspecies is represented by only a few pairs in southeastern Manitoba and southern Ontario. This species was recorded as having last nested in the Maritimes in 1972, and the last recorded nest in Quebec dates back to 1995. According to the data, there are approximately 20 breeding pairs in Ontario, and 5 breeding pairs in Manitoba. In response to the drop in the Canadian population during the last decades, it was decided to launch a captive breeding program. Consequently, current populations could potentially be increased by the release of birds bred in captivity.
The Loggerhead Shrike migrans subspecies inhabits open ranges with occasional trees and shrubs that provide nesting sites and perches from which to hunt. This species uses grazing areas where the grass is short. The fact that animals graze on the grass prevents the growth of too many trees and shrubs in these areas, which creates good feeding sites for the Loggerhead Shrike migrans subspecies. The presence of more grazing sites is typically associated with a greater abundance of Loggerhead Shrikes. The size of the habitat area is also important, because larger spaces allow the birds to avoid nesting too close to fences. This leads to greater breeding success, which may be due to the fact that predators use the fences. Very little is known about these birds’ wintering habitat.
The Loggerhead Shrike migrans subspecies returns to Canadian breeding areas in late March or early April. Although site fidelity is low, males usually return to the same territory year after year. These birds begin to reproduce in their first spring. Once the males have established their territory, they sing to attract a mate. Although the partners gather nesting materials together, the female builds the nest on her own in an isolated tree or bush, or along a fence or hedge. The nest is usually built deep inside the branches, usually in a hawthorn, and is typically found at a height of 2 to 3 m. Eggs are generally laid in May, although they can also be found as early as April and as late as early August. One egg is laid per day and an average clutch contains 4 to 6 eggs. Incubation takes approximately 16 days and is done by the female. During the laying and incubation period, she is fed extensively by the male. The nestlings are fed by both parents and the mother broods them for the first 4 or 5 days. They remain in the nest for 16 to 20 days. Adults defend their young aggressively and feed them until they learn to hunt on their own. The Loggerhead Shrike feeds primarily on large insects and occasionally on small birds, frogs and rodents. They are the only passerines that feed on small vertebrates. These birds capture their prey by swooping quickly down from an exposed perch that allows them to scan the ground. They use their sharply hooked bills to kill their prey, which they often impale on thorns or other pointed objects. This behaviour clearly illustrates this bird’s ability to find food and to attract the attention of a mate. Loggerhead Shrikes have a high breeding success rate. Ontario birds rarely attempt a second brood unless the first one fails, which is probably due to the short breeding season. Migration begins in September and the birds likely travel and winter alone.
The causes of the decline are unclear. Grazing areas, which are shrike habitat, decreased significantly in Quebec and Ontario during the last decades, and the remaining areas are extremely fragmented. However, recent surveys done in Ontario and Québec suggest that available habitat could support more breeding pairs than the currently observed numbers. Since the wintering locations of Canadian Loggerhead Shrikes migrans subspecies are unknown, a clearer explanation for the causes of the decline has not been identified. It seems, however, that habitat loss, an increased number of roads and heavier traffic on the roads in wintering quarters may have contributed to the declines. In addition, non-migratory shrikes that inhabit the south of the province year-round are territorial and may be keeping the migratory shrikes out of the best habitats. Finally, pesticides may also be a limiting factor, although the remaining birds seem to produce healthy broods.
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Loggerhead Shrike, migrans subspecies (Lanius ludovicianus migrans), in Canada
Status First posting on SAR registry
Eastern Loggerhead Shrike Recovery Team
Ken Tuininga - Chair/Contact - Environment Canada
Phone: 416-739-5895 Fax: 416-739-4560 Send Email
Recovery Progress and Activities
Summary of Progress to Date A Loggerhead Shrike Recovery Team was formed in 1992 and produced a recovery plan in 1994. In 1996, the group divided into a western team for the threatened excubitorides subspecies and an eastern team for the endangered migrans subspecies. The eastern team completed a recovery strategy in 2001. The Eastern Loggerhead Shrike Recovery Program has a toll-free number 1-866-833-8888 and a website (www.shrike.ca). Public interest in the Loggerhead Shrike and support for private land stewardship has grown, largely as a result of outreach activities and partnership with the Canadian Cattlemen?s Association and Wildlife Preservation Trust Canada. Summary of Research/Monitoring Activities Intensive studies and annual surveys of the eastern subspecies of Loggerhead Shrike began in 2000. Research projects have greatly clarified the shrike?s habitat requirements, and have identified stewardship activities that substantially increase habitat suitability. Knowledge of the shrike?s breeding range and habitat requirements has also helped to identify priority areas for outreach to landowners and, potentially, future population augmentation. Research is being conducted to help identify the reasons for the continued decline of this species. Although it is clear that habitat loss and degradation is a key threat, the rate of population decline appears to exceed the rate of habitat loss, suggesting that other threats are also involved. A bird banding program, genetic research and population monitoring are all helping researchers investigate potential threats on breeding grounds in Canada as well as on migration routes and in the wintering range. In 1997, when only 18 pairs could be found in Ontario, Environment Canada established a captive population to ensure that the unique genetic material of the Canadian birds would be preserved. While a full-scale propagation and release program will not be initiated until the causes of the decline are resolved, research is being conducted to develop effective techniques for such a program. A study of the toxicology of road dust suppressant in Ontario found that it reduced songbird and fish viability and had a particularly pronounced impact on shrikes because they hunted insects attracted to the moisture on the road. The Ontario Ministry of Environment subsequently banned the use of the chemical as a road dust suppressant. Summary of Recovery Activities Much of Loggerhead Shrike habitat occurs on private property, and habitat management is essential for the shrike?s recovery. Therefore, the cooperation and participation of landowners and land managers has been invaluable in recovery activities. Voluntary landowner stewardship activities vary according to site requirements and may include clearing overgrown areas, thinning shrubs, transplanting nest/perch shrubs or trees, and building fences or other hunting perches. Habitat improvement projects began in 2001 and approximately 12,000 acres of shrike habitat on private lands in Quebec, Ontario and Manitoba has been restored, enhanced or protected, the work conducted in large part by volunteers. URLswww.shrike.ca
Hinterland Who's Who: Loggerhead Shrike: http://www.hww.ca/hww2.asp?pid=1&cid=7&id=52
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
41 record(s) found.
- Reports on the Progress of Recovery Document Implementation (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Action Plans (1 record(s) found.)
- Permits and Related Agreements (38 record(s) found.)
Reports on the Progress of Recovery Document Implementation
Permits and Related Agreements
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