Now that I’ve talked a little bit about why bird banding is an important tool for learning things about birds that would be impossible investigate any other way, you might be wondering exactly what does take place when scientists head out to catch birds? The best way to learn, of course, is to see for yourself at a bird banding demonstration (If you’re in DC, the National Zoo will soon have a permanent bird banding demo at their exhibit on bird migration! Or, if you’re in Vermont, the North Branch Nature Center always welcomes curious bird-lovers to their bird banding sessions!). If there isn’t a bird banding demo near you–or if you think you’d rather learn from the convenience of your computer–here’s a quick photo tour of what bird banding is all about!
Step 1: Wake up before dawn…Ok, bird banding doesn’t always need to begin at dawn and, even if it does, it can continue all day! Typically, though, birds are most active early in the morning (unless you’re aiming for owls or other nocturnal species!), so mid-day banding can be a bit slower than early-morning banding. Also, birds have extremely high metabolisms and can overheat, so early banding takes advantage of the cool mornings. Plus, sun rises are so beautiful! Getting out of bed might be tough, but once you do, it’s a great time of day to be out and about 🙂
Step 2: Put up nets. They’re called “mist nets” because they are hard to see. The lines are taut horizontally, between the poles, and vertically, along the poles, but in between the taut lines, the mesh is loose and forms “pockets.” In the marsh, we used nets with two pockets, but taller nets with four pockets are common.
Step 3: Wait for birds! The nets act kind of like spider webs; unsuspecting birds don’t notice the nets, fly or walk into them, and get stuck in the pockets. The nets come in different mesh sizes, each best for a different size of bird. If the mesh is too large, a small bird could simply fly through, but if the mesh is too small, a large bird could bounce out without getting stuck.
Step 4: Check the nets every 15-30 minutes and look very thoroughly for any birds that got caught. Then, carefully extract the birds from the nets and bring them back to the banding station.
Step 5: Identify the species. Unidentified birds should never be banded (the information is useless if the species is unknown), so accurately identifying the species is the important first step!
Step 6: Carefully band the bird! Banding should always take place before any other measurements. That way, if the bird escapes, it can be identified if it is caught again. The pliers are specially made for bird bands; the little bar going off to the side opens the bands, and the tip of the pliers has two round openings that the bands can fit inside. That way, even when the pliers are completely closed, they never close more tightly than the diameter of the band, so it’s impossible to squish the bird’s leg.
Step 7: Identify the sex. In some species, males and females look different (e.g. male Cardinals are bright red and female Cardinals are a pale brownish red), so it’s easy to tell if an individual is male or female. In other species (such as the sparrows I worked with!), males and females are look exactly the same. During the breeding season, however, it’s often possible to tell males from females based on breeding characteristics: males have an enlarged cloaca for sperm storage (most bird species don’t have a penis; the cloaca serves a similar function) and females have a brood patch for incubating eggs. If you carefully hold a bird with its head and legs secure and blow air at its underside to move the feathers aside, it’s easy to tell if the bird has an enlarged cloaca or a brood patch!
Step 8: Take any measurements, samples, photos, etc.
Step 9: release the bird back into the wild!
Step 10: Proof the data sheets to make sure there are no weird mistakes (mistakes are much harder to figure out months later when the whole field season has become a big blur…). Enter the data (also much better to do immediately than to wait for a giant backlog…). Get ready to go out and do it all again!