Just a quick and dirty post before the cold, wintry mix rolls in early tomorrow morning (At least one inch of snow expected!). We’ve got a houseful of dedicated Big Bald volunteers and plenty of firewood, alcohol and food to keep us sane while the wintry weather takes its toll. I figure its a good time to post a few memories of early September, when the weather and selection of birds was a little more desirable.
I suppose it would be a good idea to explain the whole mist-netting process that we follow here at Big Bald Banding Station (BBBS) for those of you who don’t know.
In the previous post, I mentioned that we operate 18 mistnets, placed along the Appalachian Trail in various orientations and arrangements. Normally, we open these nets at sunrise and keep them open until 1 or 2 PM, so that we get in a minimum six hour sample.
Why do we start at sunrise? Passerines, or songbirds, migrate at night – primarily to avoid being predated by raptors (birds of prey) which migrate during the day. Once the sun comes up, the songbirds descend from the sky, sometimes in huge mixed flocks, to forage and build up fat reserves so they can continue their southward journey. For many of these songbirds, it’s a journey of thousands of miles from their breeding grounds in Canada or the Northeastern US, all the way down to the Southeastern US, Gulf Coast, Caribbean nations or even as far as Central and South America. It’s a spectacularly amazing journey, but to be honest there is a high rate of mortality among migrating birds. Hence our precautionary protocols which serve to minimize harm to these birds we capture.
We check the mistnets at least every 30 minutes; if its really windy, or cold, or hot we may check the nets more often so that if a bird is in one of the nets it isn’t getting blown around, frozen or roasted to death. It is the responsibility of the “net leader” to keep track of net check times and to assess conditions to determine if certain nets need to be closed. Each time the nets are checked, the “pickers” (they pick birds out of the nets) carry a stick (to lower or raise the net as needed) and a bucket with paper bags and marker. When a bird is extracted from a net, it’s placed inside a paper bag (to calm it down) with the species, net #, and time extracted written on the bag. This prevents a bird from idling in a bucket for too long at the banding table.
At the banding table, the birds are removed from the bag and a variety of different characteristics are examined. Wing chord (or length) can determine sex of the individual if the species doesn’t exhibit sexual dimorphism (meaning male and female look different). We also check for molt, which helps with aging, fat, which helps us assess the bird’s health (if its been eating well or not), and we also examine the skull – the more developed the skull, the older the bird. Any other helpful information that we need to know we usually can find in “The Bander’s Bible,” the black book visible in the photo above.
After all characteristics have been looked at, the bird is weighed then released. Most birds are completely processed in less than 5 minutes.
Occasionally, we will capture Sharp-shinned hawks in the Passerine mistnets. These small hawks are incredibly adept at hunting songbirds, so it is no surprise that they will sometimes get caught while chasing flocks of warblers through the woods. If you’ve ever fed birds in your yard then you may have seen these bite-sized super predators terrorizing the birds at your feeder.
Well, that’s all for now. Be sure to check the “Adventures Past” page for pics and info about the amazing, awe-inspiring birding trips we’ve taken in the recent past.
More to come!