The Mysterious Northern Saw-whet Owl
- Highlands IE
- Oct 28, 2021
- 2 min read
The Northern Saw-whet Owl (Aegolius acadicus) is one of the most common forest owls in. North America. In the United States it is found year round in the Northeast, the West, and Southern Appalachia. Despite it being so common, not much is known about this owl. Its nocturnal behavior and small size make it elusive and hard to study. Only general information about their habitat preference and behavior are known. The Southern Appalachian population is believed to be a disjunct population from the last glacial maximum. During this glacial period ice sheets spread over the North but stopped before reaching Southern Appalachia. Because high elevation habitats in Southern Appalachia resemble those in the Northeast, species, like the Northern Saw-whet Owl, were able to survive in this region. Once the glaciers retreated some owls remained while others returned North, creating separate colonies.
For our internship, my partner and I have been tasked with determining whether or not Northern Saw-whet owls in Southern Appalachia have a strong preference when it comes to habitat type. Very little research on the Southern Appalachia disjunct population has been done, but it is likely that their numbers are dwindling as climate change and development decrease habitat size. It was previously believed that they only resided in the high elevation Spruce Fir forests, but more recent research has shown that they also live in Hardwood habitats at lower elevations. In order to create effective conservation management plans we need to know their habitat flexibility. We teamed up with the Blue Ridge Bird Observatory who have had Northern Saw-whet Owl nest boxes up in the area for a few years. They give us the nest box location and we take habitat surveys at the sites - measuring canopy coverage, basal area, ground type, forest type, etc. Once we are done collecting field data we will run statistical analyses to see if there are any correlations between the nest box occupancy and specific habitat features. If our analysis show significant results then the data can be used to strategically place nest boxes and conserve important habitat types for these owls.
The Blue Ridge Bird Observatory mist nets for Northern Saw-whet Owls every year and adds the banding data to the USGS MAPS Program. We were fortunate enough to join along one evening. We weren't expecting to catch any of these little owls because they're so elusive. However, after playing the audio lure (mating sounds) for an hour we caught one! It was so tiny we were afraid to handle it. Luckily our mentor is an experienced bird bander and showed us all the tips and tricks. We put a sock over its head to keep it calm and took various measurements including weight, hallux and beak length among others. We shined UV light on its feathers to determine age, determined its sex using a probability chart, and banded its leg with lightweight aluminum engraved with a unique ID number. After recording all the necessary data we took the sock off its head and let its eyes readjust to the night. Once it was comfortable it flew off into the sky. We think it was a hatch year, which means we were likely the first humans it ever encountered. What an honor.
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