While the intention was to summarize the Lesser Slave Lake Bird Observatory’s 2024 Monitoring Avian Productivity and Survivorship (MAPS) program, high winds followed by rain caused several delays and we could not complete our MAPS efforts.
Yet, in what we have finished of our last period of MAPS was a first for our station: banding a Broad-winged Hawk who became the 109 species we have ever banded! While a few do breed locally, Broad-winged Hawks are not that common around any of our stations and even during migration we will only see a handful flying alone overhead. Traveling further south they begin grouping up with other hawks and by the time the flock hits Texas, thousands may be seen together kettling below the clouds. Go even further south and hawks become so concentrated that some places in Central America describe their migrations as a “river of raptors”.
Our Broad-winged Hawk is on its way south for the second time in its life and it was incredibly lucky we caught it at all. While waiting for our next net check at our site near the Boreal Centre for Bird Conservation, our field assistant Julia saw something big fly toward our nets. So she checked those nets first on the off chance that a net was holding whatever the feathered creature was. Sure enough, in the first net she came to was the hawk! Still being trained how to handle these larger birds herself, she held the net shut to keep the hawk caught until Robyn arrived.
Why did Julia need to actively hold the net closed? To picture a mist-net, first run five thin strings between two poles that are 12 m (40 ft) apart and 2.6 m (8.5 ft) tall. Between these strings fix a fine mesh with enough excess to form a bag, or what we call the net’s pocket. Different mesh sizes are used to catch different bird sizes. The mesh of our MAPS nets is much too small to capture hawks well, but sometimes big birds end up enveloped in the pocket not realizing that they can easily get out.
Thanks to quick reflexes and luck, we have captured many large birds in these nets intended to capture songbirds, including 834 Sharp-shinned Hawks, twelve Pileated Woodpeckers, five Cooper’s Hawks, and even one Barred Owl. The largest bird we have captured was before my time. On August 21, 2006, among the seven birds that were captured that day was a female Northern Goshawk – the first and only time we banded one, although two others escaped our nets in 2016.
Need to see a net in person to understand what they look like and how large birds usually escape them? Come to one of our drop-in tours most Wednesdays and Saturdays until September where you can touch and even extract a fake songbird from our demonstration net.
By Robyn Perkins, LSLBO Bander-in-Charge