When I told a friend I was writing a post about bird banding he immediately conjured up his musical past and famous bird bands: the Eagles, the Dixie Chicks, and Sheryl Crow. And don’t forget to mention Jay and the Americans, he quipped. That’s how his clever mind works, but this is about bird banding, not bands. Maybe bird bands will be a topic for a later day.
I was only too happy to accept an invitation from Gene & Mary, the hosts of the erstwhile nuthatch family, to accompany them to the Chester River Field Research Station (CRFRS), last month to observe a bird banding operation during spring migration. I had previously witnessed raptors captured in baited nets and banded at Cape May, New Jersey, but had never seen songbird banding up close. http://www.washcoll.edu/centers/ces/crfrs
CRFRS is in the River and Field Campus of Washington College, an extensive 4700 acres of mixed habitat along 2.5 miles of the Chester River, a tributary of the Chesapeake Bay. The site includes riverine, freshwater ponds, marsh, grasssland and wooded habitats, all just a 10 mile drive from the main college campus in Chestertown, Maryland.
A long dirt road through the woods leads to a small clearing and humble white shed with a “James Gruber Birding Laboratory” sign posted proudly over the door. Mr. Gruber himself and field ecologist Maren Gimpel greeted us warmly and gave an introductory explanation of the operation. One immediately grasped that these were dedicated and knowledgeable ornithologists and teachers leading a small team of enthusiastic students and volunteers. All were more than willing to answer our many questions about their work.
The interior of the “lab” itself was a crowded but efficient workplace. The workbench by the windows was where the banding took place, with clipboards, calipers, scales, and other tools-of-the-trade apparent. Along the rafters hung the small white sacs containing the captured birds from the last run, waiting to be banded, measured, and released. There was a large bookcase containing records, textbooks, and bird guides (their favorite seemed to be Sibley’s). On the wall hung large maps of the U.S. and Western Hemisphere with colored pushpins marking the sights of origin of captured and previously banded birds. A white board listed the spring arrivals for 2018.
The banding operation for the day started long before we arrived. The fine mesh mist nets were hung along strategic pathways in various habitats at dawn and monitored at least every hour to retrieve captured birds. The directors asked us not to photograph birds in the net for fear some might think the process cruel. I can assure you that these people used the utmost of gentle care untangling the birds and released them ASAP back into the wild, none the worse for wear.
Our knowledge of bird migration has been refined over the centuries. Completely unaware of migration, Aristotle thought Redstarts turned into Robins, and Garden Warblers into Blackcaps each winter. For years people thought Swallows hibernated and in the 16th century fishermen reportedly caught the torpid swallows in their nets. In the 17th century Englishman Charles Morton decided birds must indeed migrate, but he claimed their destination was the moon!
Banding has enlightened us to the specifics of migration. Audubon tied silver thread to the leg of an Eastern Phoebe to see if the same bird returned to his farm each year. Hans Mortensen first used aluminum leg rings on Starlings in 1899, and Leon Cole founded the American Bird Banding Association in 1909. In 2017 CRFRS banded 14,757 birds of 128 different species. Even though the recovery rate of banded songbirds is very low, (less than 1%), much can be learned about migration, shifting populations, and the health of the various species from this data.
“Recovery” may take many forms. It may be the netting of a hapless bird previously banded the day before, or a migrant returning to its breeding ground or just passing through. It may be a bird banded elsewhere, hundreds or even thousands of miles away. Some recoveries are by astute birders able to read the band numbers with a scope or telephoto lens, but often the recoveries are of dead birds, perhaps found as road kill, victims of window strikes, or even just old age. A notable recovery of 2017 was an Osprey found dead in Venezuela, previously banded at CRFRS in June, 2003.
I found that walking the mist nets with the guides to be exciting, much like a child with “visions of sugar plums” on Christmas Eve. You could see a netted bird from a distance and approached anxious to see it up close and try to identify it while the guide untangled and bagged the quarry. An Indigo Bunting, Ruby-throated Hummingbird, Magnolia Warbler, and Wood Thrush at two feet are truly a marvel. Even the common Gray Catbird has its own subtle beauty at that proximity.
Back at the shack the birds are fitted with the appropriate sized leg band, weighed, measured, and sexed if possible. Breeding males often have a prominent protuberance at the vent, visible when feathers are brushed aside. Age determination, (juvenile, first year, or adult) can often be determined by plumage. Fat deposits on the breast are signs of a healthy well-fed bird. All of this is painstakingly recorded. A highlight for us observers is when the guides finally handed us a bird, light as a feather, to be released back into the wild.
Two things stand out in my mind from the visit to CRFRS. Its one thing to see these birds with binoculars and photography, but entirely different to hold these small gems in your hands or hear the rapid humming of the Hummingbird heartbeat in your ear. The other lasting impression is of the knowledge and palpable enthusiasm that both the leaders and young students have for ornithology, and their obvious delight in sharing their expertise with others. We were grateful beneficiaries of their mastery that day.