With high winds and yellow leaves beginning to cover the ground, things have been quite quiet during Fall Migration Monitoring at the LSLBO this past week. The same cannot be said about our nightly owl banding program. On September 24th we banded a record-breaking 30 Northern Saw-whet Owls.
Each year, there are over 125 different stations from as far south as Alabama to as far north as Alaska which band Northern Saw-whet Owls to gain insight into their population dynamics and migratory patterns. Along with the LSLBO, these stations collaborate through Project Owlnet, which was first established in 1995.
Owls are incredibly skilled predators which sport a variety of interesting and unique adaptations which have captivated humans for centuries. One of the most well-known of these adaptations is the owl’s ability to rotate their heads with what appears to be no limitation. Although owls bring new meaning to the phrase “head on a swivel,” it is a common misconception that they can rotate their heads 360 degrees. In reality, owls are only capable of rotating their heads 270 degrees. How they can achieve such a feat is all thanks to their physiology.
When you look at an owl, it would appear as though they have short and stubby necks, if you look at the skeleton of an owl, you realize that their necks are quite long in proportion to the rest of their bodies. The human neck consists of 7 cervical vertebrae, whereas the neck of an owl contains twice as many vertebrae. This difference in structure allows for the neck of an owl to be much more flexible and maneuverable than our own necks.
If a human attempted to move their head with the same speed and range of an owl, the delicate arteries in our necks would likely stretch or tear, potentially creating a blood clot. Should a blood clot stop blood flow to the brain, it would cause an embolism or a stroke, which could be fatal. So why does this not happen to owls?
For starters, an owl’s carotid and vertebral arteries are highly connected by countless tiny vessels called anastomoses. If an artery becomes blocked, these vessels allow for the blood to be rerouted, allowing for the uninterrupted flow of oxygenated blood to the owl’s eyes and brain. An owl’s skull is also equipped with two reservoirs at the base of the skull which allow oxygenated blood to pool. A supply which an owl can tap into should blood flow be interrupted by the rotation of their heads.
For those interested in checking out our Family Owl Nights on October 3rd and 4th, all spots have been reserved so contact the Boreal Centre for Bird Conservation to join our waiting list should a spot become available at (780) 849-8240.
By Luke Strikwerda, LSLBO Boreal Interpreter
