Due to problems experienced with predation of nests and birds being harmed by their bands, banding of young birds at the nest had to be halted. Let us insist that it never be reinstated.
It is clear to me now that such a program should never be attempted on critically low populations of this species again. Bands can kill shrikes by catching on the thorns that are so intimately a part of a shrike's daily life. There are clear, confirmed and documented cases of shrikes being trapped by their bands on thorns of shrubs in the wild in Ontario and in captivity.
Also, each time fieldworkers approach a wild nest, there is a risk of attracting predators. There is strong evidence from Ontario that predators such as crows and jays learned by watching fieldworkers to find shrike nests and that this is what has increased nest losses during the years nestlings were banded. This can be seen in the nest survival data. Before the banding program nest survival was about 80%. A very high number for a songbird species. After a few years of banding nest survival dropped to about 40%. Now that banding of young in nests is not done, nest survival is back to about 80%.
For years, despite warnings from fieldworkers, program managers refused to accept that nest visits and banding were having a serious impact. Banding efforts continued and even became more aggressive and invasive until the survival data was so clear, the managers had to agree that there might be a problem. Unfortunately, this delay cost the lives of many young individuals of this endangered species.
Continued banding of wild eastern loggerhead shrikes is therefore contrary to their conservation. I hope that recovery program managers have learned this by now and heed warnings from their most experienced fieldworkers in the future.
Captive bred birds are still being banded and released in Quebec, Bruce County and in Carden. This part of the study seems acceptable to me at the present time. Please remember to report sightings. Despite the suspension of the nestling banding program, it is still important to look for and report banded shrikes. This information can still help us understand many things about wild-banded birds and released, captive-banded birds.
Background:
The Eastern Loggerhead Shrike, Lanius ludovicianus migrans, was listed as
endangered in Eastern Canada in 1991. In Ontario, where the majority of the
remaining population breeds, serious studies began in 1991. These studies and
recovery efforts are ongoing and now include a captive breeding and release
program. The Ontario population survey, which is done each year, found only 55
pairs breeding in 1992. From there the survey numbers dropped to 18 pairs in
1997, eventually recovering to 39 pairs 2002 and then crashing to about 15 pairs in 2007.
In eastern Manitoba in 2002, only seven pairs were found.
Volunteers have contributed much important information on breeding
shrikes over the years.
We now have a
good picture of the shrike's breeding range
as a result. There are
still many very important questions that, if answered, could help in
understanding the species' problems and lead to successful recovery
actions. For example, is Ontario the source of its own shrikes
or a sink fed by
immigration from other parts of the continent? How accurate are the population surveys? What are the levels of
survivorship and recruitment of young birds, and of longevity and nest site
faithfulness of adults? What are the rates of immigration and emigration between
the core breeding areas (Napanee, Smiths Falls, Cardin, Grey-Bruce, eastern Manitoba)?
Where do Eastern Loggerhead Shrikes go during the winter and what dangers are they exposed to on their wintering grounds?
The colour banding study
To answer questions like these, the Eastern Loggerhead Shrike Recovery Team, Bird Studies Canada and Manitoba Conservation began a colour banding study. The banding started in 1998 with Manitoba Conservation followed by Bird Studies Canada a year later. Each bird has one to four bands of different colours that identify it as an individual. One of the most interesting results is the discovery that birds born and banded in one core area in Ontario can move to another and breed there. This means that there is gene flow between populations. The discovery will influence how the populations will be managed in the future.
How you can help
The more information we can gather on shrike movements, the better we
will understand the situation. It is difficult for surveyors to find and
keep track of all shrikes
on their breeding grounds, let alone during dispersal and migration.
Once again volunteers are needed to
help with shrike research. Here is how you can help:
Anytime you spot a Loggerhead Shrike anywhere in North America, get out your spotting scope and have a close and careful look at its legs. If you see bands, carefully note the vertical order of the colour combinations for each leg. You may see, for example, red above light blue on the right leg and silver on the left. Record the date, where you saw the shrike and what it was doing. Waiting for the bird to show you the full length of both legs may take some patience. Please report all sightings of banded shrikes anywhere. Also, report all unbanded shrikes in Canada and in the northern US. Even dead shrikes are of interest. Report toll-free to Bird Studies Canada by calling 1-888-448-BIRD (2473).
Please note that differentiating loggerhead and northern shrikes in the field can be difficult. The Ontario Field Ornithologists web site has excellent information on Shrike Identification.
To help you determine what you see, here are some of the colours in use:
For more information on recovery efforts for the Eastern Loggerhead Shrike, visit the new Eastern Loggerhead Shrike Recovery web site.
Thanks for helping in the Loggerhead Shrike recovery process!
Created by Chris Grooms: A biologist with 12 years experience in the field with shrikes.
Please Note: This web site is my personal creation and has nothing to do with my past or present employers.
Photos copyrighted by Francois Blouin, David Okines and Chris Grooms
Web design by Susie Rance, web maintenance by Chris Grooms
To comment on the contents of this page, contact Chris Grooms.