Loggerhead Shrike

(Lanius ludovicianus)

Status: Endangered (Federal 2003 & Provincial 2008)

Table of Contents:

Species Identification
Diet
Habitat and Range
Biology and Behaviour
Similar Species
Threats/Reasons for Being Endangered
Conservation and Recovery Strategies
How You Can Help

Species Identification:

The Loggerhead Shrike is a medium-sized songbird, about 20 cm long and weighs 48 grams. They have a distinct black band across their eyes and a line of black wing and tail feathers. The head and back are mostly grey, and under the feathers are white. The bill is black and sharply angled, similar to a raptor. The female’s bill tends to be lighter in colour, especially the lower half during breeding season. The male vocalizes more often than the female, giving short, repeated trills. Shrikes give a harsh alarm call when they feel threatened.

There are 12 subspecies of the Loggerhead Shrike, but only two of them are found in Canada- the Prairie Loggerhead Shrike and the Eastern Loggerhead Shrike. They also tend to nest in loose colonies, so their distribution is patchy. The Loggerhead Shrike’s plumage colouration, tail length, and bill length all vary regionally.

Diet:

The Loggerhead Shrike earns the nickname “butcher bird” due to its hunting method of impaling prey on thorny bushes, twigs, or barbed wire. This adaptation allows them to tear at larger prey with their beak without having strong talons like raptors. The Loggerhead Shrike is an opportunistic hunter, primarily eating large insects during breeding season. Between 30-75 % of its diet is made up of grasshoppers. They also eat small vertebrates like frogs, voles, small snakes and small birds.

Shrikes wait on lookout perches and scan the area for prey. When they spot a potential meal, they swoop down to catch it and bring it to an impaling site. The impaled prey also makes a good food cache for later, also serves to mark territory, and helps to show off to potential mates.

https://www.sararegisMap Source; try.gc.ca/virtual_sara/files/cosewic/sr_loggerhead_shrike_e.pdf

Habitat and Range:

The Loggerhead Shrike is native to North America. In the southern United States and most of Mexico, populations reside year-round. Populations in Canada and the northern United States will migrate south for the winter. The eastern subspecies is found only in south-central Ontario and a couple locations in southwestern Quebec. In Ontario, the three core breeding areas are within The Land Between around Carden, Napanee, and Smiths Falls.

Loggerhead Shrikes are found in grasslands and shrublands. Their preferred habitat includes small trees and shrubs for nesting, with elevated perches for hunting and keeping a lookout, thorny shrubs or barbed wire fence, and open areas for foraging. Perches are used to sing and attract mates, and to defend their territory. A range of habitat types might have these features including alvars, shrub-steppe, old fields, and pastures (natural or cultivated). In Ontario they are often associated with alvars or fields that have Hawthorn and Red Cedar. In 2009 studies found that their territory size ranged from 2.7 to 47 hectares in Carden, and 2.9 to 11.7 hectares in Napanee. Before European settlement, Loggerhead Shrikes nested in native grasslands, but today most of these grasslands are gone, and shrikes have shifted to nesting in agricultural fields and rock barrens. Only 1% of native tallgrass prairie habitat remains in Ontario.

Biology and Behaviour:

Canadian populations arrive at their breeding grounds starting in late April and head south by September. The males arrive first to establish territory, and the female will choose a mate based on the quality of the territory. Both sexes help to build an open cup nest in the crook of a small tree or shrub (Hawthorn is preferred), using twigs, and then they will line it with fur. An average of 5-6 eggs are laid and incubated for 15-17 days. Hatchlings remain in the nest for another two to three weeks. Both parents continue to feed fledglings for about a month. Usually there is just one clutch, but if their original nest fails, they may rebuild if it is still early in the season.

Predators include magpies, crows, feral cats, foxes, raccoons, and some snakes. Risk of predation is especially high along roadways where the shrikes may be nesting within hedgerows. Single, isolated trees are preferred nesting sites, but hedgerows are being used more often, as preferred sites are hard to find.

Image taken from Ontario Field Ornithologists: http://www.ofo.ca/site/page/view/articles.shrikeid

Similar Species:

While the Northern Shrike breeds further north, it may be seen in south and central Ontario during the winter. They look fairly similar to the Loggerhead Shrike, but they have fine barring on their sides and breast, light brown upper body, and the black mask does not extend above the eyes. The Northern Mockingbird also looks similar, but has no mask on the face, and they are slimmer overall.

Threats/ Reasons for being at Risk:

1. Loss and degradation of breeding, migration, and wintering habitat: Historically, the Loggerhead Shrike’s original grassland habitat throughout North America was largely converted to farms or residential areas. Today, shifting farming practices and farm abandonment is allowing for succession and affecting the amount of nesting habitat available to them. Conversion of agricultural land from pasture to crops is also problematic in their wintering habitat south.

2. Pesticides: As a top predator, the Loggerhead Shrike is vulnerable to bioaccumulation. Traces of potent insecticides that were banned in the 1970s and 1980s are still present in all levels of our ecosystems. For instance, DDE was found in Loggerhead Shrike eggs in Ontario in 2010. Chemicals also impact the shrike’s food supply, especially insecticides that target grasshoppers.

3. Predation leads to reduced nesting success: Loggerhead Shrikes often nest in hedgerows along roads and mammal travel corridors, making them vulnerable to predators. In areas where predation is high, nest success may be as low as 35%. Predators like corvids, raccoons, and cats have all adapted to urbanization and are able to thrive.

4. Road mortality: Shrikes tend to fly low along roadways, and their use of hedgerows and fences along roads makes them more vulnerable to vehicles. Drivers should keep an eye out for low-flying birds as they travel.

Conservation and recovery strategies:

Many partners have come together to help Eastern Loggerhead Shrikes in Ontario. There has been increased monitoring and a captive breeding and release program. There has also been an effort to restore and expand suitable habitat and raise public awareness about this species and their requirements

How can you help?

If you see a Loggerhead Shrike, contact Wildlife Preservation Canada. Email admin@wildlifepreservation.ca or call 1-800-956-6608.
Creating and preserving habitat for this species is especially important. Landowners aim to keep at least 15% grassland cover and follow best management practices, such as creating smooth-edged patches.
If you have Loggerhead Shrikes on your property, make sure you stay away from their nests from April to August. They are sensitive to disturbances as far as 400 m from their nest site. The species is protected under provincial and federal law, so do not alter habitat or (e.g. removing trees) in this area.
If nesting Loggerhead Shrikes are confirmed by experts, landowners will be eligible for the Conservation Land Tax Incentive Program. You may also receive funds for installing fencing, or other activities that help maintain pastures.
If you don’t have Loggerhead Shrikes on your property, you can create habitat for them by following steps in this guide. Well-spaced Hawthorn and Red Cedar can be particularly good habitats.

Quick Facts:

The Eastern Loggerhead Shrikes within Ontario are the only migrating populations. More research is being undertaken to learn about their migratory routes
The Loggerhead Shrike Working Group is an international team of researchers created in 2013 to address the needs of shrikes across political boundaries. The group has annual meetings, and has been recognized for their collaborative approach to conservation - their effective model could be replicated for other species plans
Loggerhead Shrike caches are called “Larders” or “Pantries”. You can report sightings of impaled animals to the Larder Locker page on iNaturalist

Additional Resources:

Wildlife Preservation Canada Loggerhead Shrike Page: An Ontario Landowner’s Guide
The Nature Conservancy of Canada has a profile page and a podcast episode on the Loggerhead Shrike
Hinterlands Who’s Who profile
The Ontario Field Ornithologists Shrike ID page
The Cornell Lab All About Birds page

Sources:

Bezener, A. 2000. Birds of Ontario. Lone Pine Publishing. Edmonton, AB.

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. (https://www.sararegistry.gc.ca/virtual_sara/files/cosewic/sr_loggerhead_shrike_e.pdf)

Eastern Loggerhead Shrike Recovery. Loggerhead Shrike: an Ontario Landowner’s Guide.

Ontario Ministry of Natural Resources and Forestry. 2016. Recovery Strategy for the

Loggerhead Shrike (Lanius ludovicianus) in Ontario. Ontario Recovery Strategy Series.

Prepared by the Ontario Ministry of Natural Resources and Forestry, Peterborough,

Ontario. v + 9 pp. + Appendix vii + 35 pp. Adoption of Recovery Strategy for the

Loggerhead Shrike, migrans subspecies (Lanius ludovicianus migrans), in Canada

(Environment Canada 2015).