Purpose
We work to prevent the eastern loggerhead shrike from disappearing by building the wild population in Ontario, and studying the species to learn more about the threats they face.
Eastern loggerhead shrikes are one of Canada’s most endangered songbirds. In the past, they could be found from Manitoba to New Brunswick. Now, however, there are fewer than 25 breeding pairs, restricted to two small isolated pockets in Ontario: the plains of Carden and Napanee.
After a precipitous drop in the wild eastern loggerhead shrike population in the 1990s, Environment Canada invited Wildlife Preservation Canada to lead the multi-partner recovery effort in 2003. Since then, the wild population size has fluctuated. Studies have shown that although the recovery effort has prevented the species from disappearing from Canada, more work is required to identify and address the causes of the species’ decline.
We work to prevent the eastern loggerhead shrike from disappearing by building the wild population in Ontario, and studying the species to learn more about the threats they face.
In 2023 we plan to have:
The cornerstone of our shrike program is breeding birds and releasing their young to boost the wild population. Within just a few years of launching our field breeding program, we saw one of the released birds successfully migrate and return to breed with a wild shrike. This achievement was a first for a migratory songbird conservation breeding effort and brought international acclaim to the program. Since then, we’ve seen many birds returning to Ontario, often breeding and contributing more young birds to the wild population.
We house these shrikes in large enclosures situated out in the field. This exposes the young to natural habitat, including predators and prey, and allows them to develop a full range of survival skills. As part of our soft-release technique, we continue to provide some food after the young are released. Wildlife Preservation Canada coordinates the conservation breeding and release program, which includes several partners that provide breeding and overwintering facilities. Currently we release young in the Napanee and Carden plains, to supplement existing wild populations in these two core areas.
We track the number of shrikes in the wild through habitat surveys, nest monitoring and colour-banding, giving us insights into return rates, population size, movements between core areas and the success of the breeding and release program. We couldn’t do this without the help of our Adopt-A-Site survey volunteers. If you’d like to become involved, contact us.
You can checkout our most recent results from the 2023 survey here.
The shortgrass habitat that shrikes need is found mainly on private land. For many years, we have worked with landowners to protect and enhance shrike habitat on their property, ensuring that shrikes have suitable nesting sites and hunting grounds.
Our research has identified the habitat features that shrikes need: from the nest tree, territory and habitat patch to landscape-level requirements. In addition, we are investigating nest predation to identify which species are the biggest threat and how habitat plays a role. The results from our ongoing research are used to improve our practices and stewardship guidelines for shrike, and we share this knowledge widely.
Although little is known about shrike migration and wintering behaviour, it appears that the biggest causes behind the decline of this species are occurring outside Canada.
That’s why we are working with U.S. conservation partners and applying the latest tracking technologies to learn where eastern loggerhead shrikes spend the winter and what routes they take to get there. With this information in hand, we can then work with our U.S. partners to identify and confront threats during migration and overwintering to reverse declines.
2024 Conservation Strategy for the Eastern Loggerhead Shrike and SCP Workshop Report now available.
Results
The shrike recovery program has seen a number of successes to date. We are learning more about the threats to the wild population, and thousands of acres of habitat have been restored or improved.
Since 2003, the conservation breeding program has released over 1,300 young birds in Ontario!
Not only are many of these birds returning the following spring, some are returning year after year. In 2012, for example, a six-year-old female released in 2006 returned to pair with a wild male — solid evidence that the field breeding and release techniques are working.
Up to 36% of shrikes spotted in the wild have been birds released from our conservation breeding program in previous years. The majority of these birds pair successfully with wild mates and contribute a significant number of young to the wild population.
Meanwhile, we continue to gather clues about where our Ontario birds go during the winter, and how they get there. So far, we have evidence that a portion of Ontario eastern loggerhead shrikes winter in both the north- and south-eastern United States, and there is a clear link with the Virginias, with birds banded in Ontario seen in Virginia, and vice versa. Tracking data has so far revealed two potential migratory strategies in Ontario, with some birds heading southwest to pass in to the U.S. around Windsor, and others appearing to head more directly south to hop across Lake Ontario. Lately we’ve also tracked birds migrating through Pennsylvania during both their spring and fall migrations, and with each year of tracking data collected the picture of shrike movements to and from Ontario is coming into clearer focus.
Impact
We have proven that we can breed shrikes capable of surviving and thriving in the wild. Birds released from our conservation breeding program have successfully migrated south and returned to Ontario at a rate at least as high as their wild-born counterparts. According to population viability analyses conducted in 2009 and 2015, conservation breeding alone is unlikely to restore the wild population to a self-sustaining level. However, the release of young birds has certainly had a stabilizing effect and the situation would be even worse without the breeding effort. The graph below shows the number of birds that have been found in the wild in the two main core areas, Carden and Napanee, since Wildlife Preservation Canada took over program coordination.
Releases began in Carden in 2005 and in Napanee in 2012, and populations in each area nearly doubled in the years following those efforts. Though it’s difficult to attribute those upturns in the population to any one factor, the release of juveniles has certainly had a positive effect on the numbers of birds we’ve seen in the wild, as birds coming from the conservation breeding program have averaged 20-30% of the wild population in recent years.
So far, the conservation breeding program is doing its job: keeping eastern loggerhead shrike present in Canada while we work to discover and address the causes of loss during the migration cycle. Once we address those causes, the conservation breeding will be an essential tool in helping the wild population begin to grow again.
The techniques we have developed can also be applied beyond eastern loggerhead shrikes. An external review of the conservation breeding program in 2008 suggested that it would ultimately provide a model for future recovery programs for other shrikes in North America and — even more broadly — for other migratory songbirds at risk.
Publications
Eastern Loggerhead Shrike Annual Reports
2022 Field Report
2021 Field Report
2020 Field Report
2019 Field Report
2018 Field Report
2017 Field Report
2016 Field Report
2015 Field Report
2014 Field Report
2013 Field Report
2012 Field Report
2011 Field Report
2010 Field Report
2009 Field Report
Home on the Range Newsletter
From the archives
Fall/Winter 2017
Spring/Summer 2017
Fall/Winter 2016
Spring/Summer 2016
Publications
Geldart, E.A., Howes, L-A., Wheeler, H., Mackenzie, S.A. 2023. A review of Impacts of Tracking Devices on Birds. North American Bird Bander. 201 – 212.
Hudecki, J., Wheeler, H., and A. Chabot. 2021. Evidence and Impact of Plastic Use by the Loggerhead Shrike (Lanius ludovicianus). Wilson Journal of Ornithology 132(3): 729-733
Schutten, K., A. Chabot, and H. Wheeler. 2021. West Nile virus seroconversion in Eastern Loggerhead Shrike (Lanius ludovicanus migrans) after vaccination with a killed vaccine. Journal of Zoo and Wildlife Medicine. 52(1): 185–191.
Chabot, A., Steiner, J., Wheeler, H. 2019. The Plight of the Loggerhead Shrike: A One-Plan Approach to Saving an Iconic Grassland Bird in North America. Animal Keeper’s Forum 46, 153-157.
Parmley, E.J., D.L. Pearl, N.A. Vogt, S. Yates, G.D. Campbell, J. Steiner, T.L. Imlay, S. Hollamby, K. Tuininga, and I.K. Barker. 2015. Factors influencing mortality in a captive breeding population of Loggerhead Shrike Eastern subspecies (Lanius ludovicianus ssp.) in Canada. BMC Veterinary Research doi:10.1186/s12917-015-0429-2
Lagios, E.L., K.F. Robbins, J.M. Lapierre, J.C. Steiner, and T.L. Imlay. 2014. Recruitment of juvenile, captive-reared eastern loggerhead shrike Lanius ludovicianus migrans into the wild population in Canada. Oryx 49, 321-328. doi:10.1017/S0030605313000690
Steiner, J., A.A. Chabot, T. Imlay, J.-P.L. Savard, and B.J.M. Stutchbury. Field propagation and release of migratory Eastern Loggerhead Shrike to supplement wild populations in Ontario, Canada. In Soorae, PS (Ed.). 2013. Global Re-introduction Perspectives: 2013. Further case studies from around the globe. Gland Switzerland: IUCN/SSC Re-introduction Specialist Group and Abu Dhabi, UAE: Environment Agency-Abu Dhabi. xiv + 282 pp.
Imlay, T.I., J.F. Crowley, A.M. Argue, J.C. Steiner, D.R. Norris, and B.J.M Stutchbury. 2010. Survival, dispersal and early migration movements of captive-bred juvenile eastern loggerhead shrikes (Lanius ludovicianus migrans). Biol. Conserv.143, 2578-2582.
Nichols, R.K., J. Steiner, L.G. Woolaver, E. Williams, A.A. Chabot, and K. Tuininga. 2010. Conservation initiatives for an endangered migratory passerine: field propagation and release. Oryx 44, 171–177. doi:10.1017/S0030605309990913.
Landowners
Loggerhead Shrike: An Ontario Landowner’s Guide
Project partners
Project supporters