I watched while Steve Cox delicately removed a Black-chinned Hummingbird from one of the mist nets at the Rio Grande Nature Center. “These nets were not designed to catch hummingbirds,” he explained. Because the volunteers from Rio Grande Bird Research are not licensed to band hummingbirds, it would be released.
“Open your hand,” Steve instructed. He then placed the shaken hummer in my hand. It was so light I could hardly feel it. It was on its back and didn’t move. Steve gently began turning it over until it was on its stomach. “Gently raise your hand,” he suggested, at which point the tiny bird flew to its freedom.
As we walked back to the banding station, Steve shared information about the bird research conducted through the banding. Rio Grande Bird Research, Inc. is an all volunteer effort that began in 1979, before the state park was established. Steve, a field biologist, is the volunteer director. Through the data they collect, they are able to track trends, which they use to educate land management organizations in the Rio Grande Valley. They serve an educational function for both high school and college students, as well as members of the public that participate on the weekend bird walks at the Nature Center.
It was 8:30 and the volunteers had been at the park since just before dawn, to assure that the nets were in place before migrating birds made their descent into the bosque to refuel and rest. The nets are checked every 20 minutes to make sure birds are not stranded too long.
At the banding station, one of the volunteers was banding and collecting data on a Yellow Warbler. Gale, another one of the volunteers, recorded the data, starting with which net it had flown into and the time it was retrieved. Holding the warbler between two fingers, the bander measured the length of its wing, checked for parasites and blew on its breast to determine the amount of fat visible through its thin skin, relaying each piece of information to Gale. Taking the bird, Steve fanned the feathers in one of the wings and showed us how to see the growth bars that determine whether it is, like this warbler, a hatch year bird. It was then placed upside down in a film cartridge to obtain its weight. This one was 10 grams, or a little over half an ounce! She finished by placing the band around the warblers leg. Each band has a unique ID number issued by the U.S. Fish and Wildlife, which also issues licenses to banding organizations.
A group of young research assistants came in carrying a net bag with a Northern Flicker and the process began all over again. “See the red streak on its check. It is a male,” Michael, a high school student and one of the regular banders, explained to Jaxon, an 8th grader who was watching the banding for the first time. Steve had the students check a detailed bird identification guide, which Michael called their banding bible. From the drawing of feather patterns of flickers, they were able to determine that the flicker was a juvenile. It needed a larger container to be weighed and Michael dug a potato chip can out of the equipment bag.
When I left, the warbler and flicker were hanging in net bags, ready to provide an educational opportunity for the five birders participating in the morning bird walk. They too would have the opportunity to observe a bird up close and have the thrill of releasing it back into trees.