Loggerhead Shrike
(Lanius ludovicianus)

Overview

Summary

© Tony Battiste
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In Canada, the Loggerhead Shrike is mainly a species of the shrubby prairie grasslands (L. i. excubitorides), but also occurs in very small numbers in south-central and eastern Ontario's alvar ecosystems (L. i. migrans; taxonomy is under review). Breeding Bird Surveys and other survey programs indicate that the Loggerhead Shrike has experienced a marked decrease in the national population since the early 1970s. The two subspecies were listed under the Species at Risk Act in 2005 (excubitorides) and 2003 (migrans). The Loggerhead Shrike has been the focus of conservation actions, including a recovery program and a captive breeding and release program (Environment Canada 2010c, Environment Canada 2014a). This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.

Designations

Population status

Population estimate

Distribution maps

• COSEWIC: Distribution of the Loggerhead Shrike
• North American Breeding Bird Survey (BBS): Relative Abundance and Breeding Distribution (1970-2016)
• Atlas of the Breeding Birds of Ontario (2001-2005): Breeding evidence
• Manitoba Breeding Bird Atlas (2010-2014): Breeding Evidence

Migration strategy, occurrence

Responsibility for conservation

General nesting period in Canada

Conservation and management

The Loggerhead Shrike has faced significant habitat loss and degradation across the wintering and breeding grounds (COSEWIC 2014). These habitat changes have been correlated with range-wide population declines. However, range-wide habitat loss is likely not the only cause of the population declines; suitable habitat remains unoccupied in areas of the United States and Eastern Canada, suggesting other potential factors at play (COSEWIC 2014). Other possible threats include: pesticides, road-associated mortality, adverse weather and interspecific competition (COSEWIC 2014). In Ontario, range retraction may be the result of natural succession allowing the vegetation to develop beyond the shrubby grassland stage preferred by Loggerhead Shrikes (Chabot 2007). For information on the legal status of the subspecies under the Species at Risk Act (SARA) and to view the Recovery Strategy, see the SARA Registry.

Bird conservation region strategies

Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:

• conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
• stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
• management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
• other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

References

• Chabot, A.A. 2007. Loggerhead Shrike. pp. 360-361 in: Atlas of the Breeding Birds of Ontario, 2001-2005. Cadman, M.D., D.A. Sutherland, G.G. Beck, D. Lepage and A.R. Couturier, Eds. Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature, Toronto, Ontario.
• COSEWIC. 2014. COSEWIC Assessment and Status Report on the Loggerhead Shrike Eastern Subspecies Lanius ludovicianus ssp. and the Prairie Subspecies Lanius ludovicianus excubitorides in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xiii + 51 pp. COSEWIC. 2014. COSEWIC Assessment and Status Report on the Loggerhead Shrike Eastern Subspecies Lanius ludovicianus ssp. and the Prairie Subspecies Lanius ludovicianus excubitorides in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xiii + 51 pp. (Link)
• Environment Canada. 2010c. Recovery Strategy for the Loggerhead Shrike, migrans subspecies (Lanius ludovicianus migrans), in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. viii + 35 pp. Environment Canada. 2010c. Recovery Strategy for the Loggerhead Shrike, migrans subspecies (Lanius ludovicianus migrans), in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. viii + 35 pp. (Link)
• Environment Canada. 2014a. Recovery Strategy for the Loggerhead Shrike, excubitorides subspecies (Lanius ludovicianus excubitorides), in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. iv + 23 pp. Environment Canada. 2014a. Recovery Strategy for the Loggerhead Shrike, excubitorides subspecies (Lanius ludovicianus excubitorides), in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. iv + 23 pp. (Link)
• Environment Canada. 2015a. Recovery Strategy for the Loggerhead Shrike Prairie subspecies (Lanius ludovicianus excubitorides) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa iv + 23pp. Environment Canada. 2015a. Recovery Strategy for the Loggerhead Shrike Prairie subspecies (Lanius ludovicianus excubitorides) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa iv + 23pp. (Link)
• Environment Canada. 2015b. Recovery Strategy for the Loggerhead Shrike, migrans subspecies (Lanius ludovicianus migrans), in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. vii + 35 pp. Environment Canada. 2015b. Recovery Strategy for the Loggerhead Shrike, migrans subspecies (Lanius ludovicianus migrans), in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. vii + 35 pp. (Link)
• Second Atlas of the Breeding Birds of Southern Quebec. 2017. Regroupement QuébecOiseaux, Environment and Climate Change Canada's Canadian Wildlife Service, and Bird Studies Canada. Québec, QC. Data obtained from the website on 27 February, 2017. Second Atlas of the Breeding Birds of Southern Quebec. 2017. Regroupement QuébecOiseaux, Environment and Climate Change Canada's Canadian Wildlife Service, and Bird Studies Canada. Québec, QC. Data obtained from the website on 27 February, 2017. (Link)