Just the other day I was marveling at the quality of this summer; not just the sun and heat, but the lack of wind. I blame myself for saying it out loud, but the Lesser Slave Lake area seems to have remembered that it likes being windy. The arrival of wind has certainly put a damper on migration and our banding totals over the past week. I know I have said it many times to many people that birds aren’t very active on windy days, but I also know that people are sometimes confused by that. Why birds don’t migrate when there is a headwind makes sense, but I often get asked why birds don’t take advantage of tailwinds to help them migrate faster. To a certain extent they will, but it doesn’t take much for the wind to go from helpful to dangerous. Most migratory songbirds have a cruising speed of about 30 km/hour. Our wind speeds are often 30 gusting to 50. To put it into perspective, it is like you driving down the highway with a tailwind of 100 gusting to 170. Also take into account that birds are extremely light in comparison to their surface area – so it’s like driving a tiny little car with a billboard on its roof through extreme winds. So what do birds do in the wind? Some will definitely continue to migrate, but they will do so slower and deeper in the forest, moving through the treetops in between gusts of wind. Most, however, will use poor weather as an opportunity to rest and feed so that they are ready to give it their all once the weather becomes favourable again. If the wind becomes extremely strong they often simply hunker down near the trunks on branches lower in the trees. This leads into an interesting and related topic. How do birds stay perched in such strong winds? A visitor asked the other day how birds stay so firmly attached to their perches and how they are able to sleep without falling. Birds have very specially designed legs and feet that make keeping their grip an involuntary reflex. They have long thin tendons that run along the backs of their legs attaching the muscles high in their legs all the way down to their toes. When a bird bends its legs the tendons are pulled tight over the outside/backside of their ankle joint and the toes lock onto the perch (the main joint you can see on a bird’s leg is its ankle and the main part of its ‘leg’ is actually congruent with our foot). The toes will stay locked until the bird straightens its leg and relieves the tension on the tendon. Falling asleep actually helps a bird to further tighten its grip because as it relaxes its weight settles onto its legs and causes them to bend even more which adds even more tension to the tendons.
Weekly Banding Reports
- September 28 – October 3, 2023
- September 21 – 27, 2023
- September 14 – 20, 2023
- September 7 – 13, 2023
- August 31 – September 6, 2023
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2 weeks ago
The early migrants are arriving in Slave Lake with sightings of Juncos, American tree sparrows, and our first robin this week. So that means our own Robyn will be starting up the Spring Migration Monitoring program at the station soon. If you would like to support our amazing team and bird conservation programs, you can send a donation to our Team Tanager in the Great Canadian Birdathon! www.canadahelps.org/en/charities/Birds_Canada/p2p/birdathon24/team/lesser-slave-lake-bird-observa...
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4 weeks ago
Are you looking for a unique fieldtrip for your students this spring? Check out our hands-on programs for students from Grade 1 to post secondary. Just a reminder that we are only able to offer these programs during the spring migration season from mid May to June 10th. So call soon as dates are booking up fast. Interested in knowing more about what a bird observatory tour is like? Check out our LSLBO Video tour: www.youtube.com/watch?v=7qOPibmMQaU
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2 months ago
Friday (Feb 16) is the LAST DAY to apply for our MIGRATION FIELD ASSISTANT position at the LSLBO!If you have good birding skills and want to gain more hands-on field experience in the world of avian migration monitoring, visit our job board for more information on this rewarding position: www.lslbo.org/job-opportunities/migration-field-assistant/
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