Last week I got a very interesting call. It was the Information Officer, Michelle, from the Boreal Centre calling to tell me that a man was there who wanted help identifying a picture of what he believed to be a bay-breasted warbler hybrid. Naturally I was skeptical but curious. Hybrids are very rare in the bird world. There are a lot of factors working against their existence. For starters, female birds are attracted to a particular mate by its song – a female bird will only respond to the song of her species’ male. Then, once attracted to check out the male, she will evaluate his appearance and decide if he looks like a suitable mate. Even if the female bird responds to the wrong song and fails to recognize the male as the wrong species chances are good that he won’t acknowledge her since she is not what he is instinctually programmed to look for. If the two confused love-birds make it past all that, they face the challenge of actually creating viable eggs. Finally the young hybrids have to grow and survive migration. And this is the only way a hybrid can be made; in birds, male hybrids are fertile, but females are not (mammals are the opposite), so a hybrid cannot breed with another hybrid to perpetuate its kind. I’m not statistician, but those can’t be good odds. Then throw in someone actually seeing this bird… Most hybrid reports are not hybrids at all. There are a few situations that can cause a bird to not look how it is supposed to. In birds that have an alternate moult (i.e. specific breeding plumage); young birds often don’t have as bright or well-defined alternates, and if a bird comes under stress while undergoing its alternate it may only get half-way through it giving the bird a rough, unfinished look. Birds can also be what’s called leucistic, which is when they lack black pigmentation. Leucisism is often mistaken for albinism which is a lack of all colour pigmentation (albinos always have pink eyes as a result of this; any animal that is ‘albino’ without pink eyes is actually leucistic). The opposite of leucistic is melanistic which is having too much black pigmentation. Either of those pigment anomalies can cause a bird to not look right. So imagine my excitement when I arrive at the BCBC and the pictures are not only close and in-focus (aren’t all pictures of rarities supposed to be blurry?), but they are of what appears to be a bay-breasted warbler and blackburnian warbler hybrid. The bay-breasted half of him was easy to see – he sang like a one and had an obvious bay coloured breast but the other parent was harder to figure out. My first impression was that it was a black-and-white warbler based on the heavy white eyebrow and white stripes on a black back. Upon further inspection I believe that the other half of it is actually a blackburnian warbler. Excluding colouration, the facial pattern is an exact match to that of a blackburnian and although it is hard to see in the picture there is also has a small coloured marking on the crown of its head. Many warblers have stripes down the crown of their head or concealed crown patches, but a small coloured spot on the top of the head is distinctive of the blackburnian. The stongest evidence I have to support my theory of its parentage, however, is its wingbars. Only two species of warbler have such wide wingbars that converge together in a white patch: the blackburnian and the magnolia and considering it has no other characteristics similar to a magnolia I am left with the blackburnian. These two species do have similar songs and live in similar habitat so it is not surprising that they have been reported to hybridize before, but this is still a truly rare sighting. The picture was taken by a man named Istvan Orosi, an avid bird photographer; he is planning to make sure it is properly reported so it can be confirmed.
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On November 1st, we banded our last bird of the 2026 field season. Unsurprisingly, since Owl Fall Migration Monitoring is our last monitoring program to wrap up, it was this beautiful Northern Saw-whet Owl! In total we had an above average, but not record-breaking year with 165 Northern Saw-whet Owls and 7 Boreal Owls banded. Stay tuned for our full year in review when we publish our 2026 Annual Report in early January. Missing the birds already? Join us for the 32nd Annual Slave Lake Christmas Bird Count happening on Saturday, Dec. 19th this year! Stay tuned for more information soon. Note: Birds are handled by professionals and released unharmed as permitted by federal and provincial authorities.
On Sept 13, 2026, our owl researcher Robyn Perkins banded a young female Northern Saw-whet Owl at the Boreal Centre for Bird Conservation (band 1124-61706). She was a hatch-year (hatched this spring/summer) and heading out on her first migration. We were excited to learn that she was recaptured just a month later on Oct 15, 2026 at the Rocky Point Bird Observatory in Victoria BC. Despite her young age, she crossed the Rocky Mountains and already travelled over 1300 kilometers during her first fall migration! Even more amazing, this is the second Northern Saw-whet Owl originally banded by the LSLBO (2016) and later recaptured at Rocky Point BO (2018). Thank you to Rocky Point Bird Observatory for sending us such great pictures of this little traveller.
We are thrilled to announce that Birds Canada installed a Motus Wildlife Tracking System (motus.org/) tower last week at the Lesser Slave Lake Bird Observatory. A program of Birds Canada, Motus is an international collaborative research network that uses automated radio telemetry to track the movement and behaviour of small animals, like birds, bats, and even insects. There are almost 2500 Motus stations around the world and that number is growing every day! Motus stations are constantly listening for tiny, lightweight nanotags that have been deployed by researchers on small flying animals. When a tagged animal flies within 10 - 15 km of a tower, its unique signal can be detected and uploaded to the shared database managed by Birds Canada. If it is detected at multiple Motus stations, we can start tracking that individuals’ migratory movements. Situated on a major migratory flyway on Lesser Slave Lake, we are hoping that this Motus station will provide the opportunity to gain a better understanding of the migratory movements and habitat needs of the boreal bird species that we monitor at the LSLBO. For more information on the Motus program, check out motus.org. We would like to thank Birds Canada and Alberta Parks for all of their support for the establishment of the LSLBO Motus station!