Bird Banding: Helping Research and Educating Ourselves
By Andy McCormick
While attending the Western Field Ornithology conference in August, I decided to try something new and skipped the field trip one morning to participate in a bird banding workshop. It was my first experience with bird banding, and it was a treat to see birds close-up and hold a live bird in my hand! We also learned a lot about feathers and what they tell us about a bird’s age.
We arrived at 6 a.m. at the Rio Grande Nature Center State Park banding station in Albuquerque, NM and a crew of six volunteers had already set up the mist nets and were beginning to examine birds. We were escorted by Steve Cox, who has served as the station manager and oversees the enthusiastic group of volunteers who capture the birds, and then inspect, measure, and band them. They catalogue all the birds they capture and on the day we visited, they captured and measured over 60 different birds. The station has been operating for 40 years and has amassed data on birds migrating through the Middle Rio Grande River Bosque.
The term bosque is derived from the Spanish for woodlands and refers to riparian forest land along rivers, streams, and ponds in the southwestern United States. The Rio Grande Nature Center State Park is situated at the northern end of the Middle Rio Grande River Bosque, which extends from Santa Fe, NM to El Paso, TX, and forms the largest bosque in the country. The most famous area along this stretch of river is the Bosque del Apache National Wildlife Refuge.
The banding station at the nature center operates on Saturdays and Sundays and uses mist nets to capture birds. Mist nets are made of fine soft polyester or nylon strings spaced from 30 to 38 millimeters apart. Finer mist nets are available for hummingbirds. Larger mesh is used for larger birds. The nature center station sets out 20 mist nets at dawn and captures birds until about noon. The full nets are usually 2.6 meters high (8.5 feet) and from 6 to 18 meters long (19.6 to 59 feet). The nets are attached to poles by a series of trammel lines each supporting a shelf of baggy netting. Each net has four shelves which hang from the trammels so that when a bird flies into the net, the netting gives way from the impact and catches the bird in a soft landing. The bird then falls from its own weight into a pocket formed by the shelf it is in, and the one below.
Banding station team volunteers monitor the nets every 25 minutes so that a bird will not have to stay tied up in the net for very long. This is especially important at the Albuquerque site when August temperatures can hit 900F by noon. The birds are detached from the net by carefully unhooking their feet and head. Once free of the net, the bird is put into a soft porous pouch to be carried to the banding station for measurement.
Each bird is logged noting its identification to species or subspecies, sex, age, and then weighed. Bird banders learn how to safely hold the bird around its neck between the index and middle fingers and cupped in the palm of the hand. The bird can easily be turned over for inspection of its fat reserves when the bander softly blows the feathers apart on the belly. The quality of the fat reserves is also logged. Finally, a metal band etched with serial and telephone numbers is attached to the bird’s leg, so that the station can be notified if anyone finds the bird or if it is recaptured in the future.
Bird banding is important for continuing research on bird nesting and migration patterns, and for educating birders about aging birds from the condition and molting stage of their feathers. We saw many hatch-year birds (those newly hatched this year) with new feathers identified by the crisp edges and pointed tips. Older feathers on adult birds will look worn and the tips can be frayed or broken. Using the quality of a bird’s feathers to determine a bird’s age can be an excellent aid in identifying birds in the field.
During our morning at the station we saw a very nice variety of birds banded. A sample of the birds captured includes MacGillivray’s, Wilson’s, and, Prothonotary Warblers, Gray Flycatcher, Bewick’s Wren, and Black-chinned and Calliope Hummingbirds. We were all given a chance to hold a bird for a few seconds and instructed on how to safely allow it to fly off our hand and on its way. The visit was a fine alternative to the field trip and I’m sure what I learned will help me be a better birder.