Hummers in the Hand
By Matt Norris
Hummingbirds are the most marvelous and magnificent of creatures. People have always loved to watch them, but very little was actually known about them. Beginning in the second half of the twentieth century, attempts were made to discover more about hummingbirds. Researchers realized that they would need to catch the birds to better examine them. As a result, they developed special handling techniques and established hummingbirds banding and monitoring stations.
Throughout the era of hummingbird banding, the techniques and methodology of banding hummingbirds have helped discover important information. The ongoing banding stations provide data for research on age, sex, range, foraging habits, population density, productivity, survivorship, and habitat use. This important information is used in the conservation and protection of breeding and wintering grounds and migratory habitats.
Hummingbird banding stations are operational year round. It is important to do so, so that researchers can see the population and diversity of hummingbird species. A year, as far as hummingbirds see it, is made up of four parts; spring migration, breeding season, fall migration and wintering season. Trained personnel are essential to the operation of banding stations. There are three groups instrumental to the successful operation of a banding station – the trappers, the banders and the recorders. The three groups work together like an assembly line, working quickly, in order, and very efficiently.
The trappers start the process. They wait and capture the birds. Capture techniques vary from group to group. The group I was part of used what’s called a Hall Trap. A Hall Trap is a fine mesh covered drop trap. A hummingbird feeder is located at the center. When a hummer lands on the feeder, the trapper tosses the line he or she is holding and the screen mesh falls, trapping the bird. The trapper reaches into the trap, gently puts the bird in a mesh bag, and then brings the hummingbird over to me, the bander.
While the bird is still in the bag, the first thing I do when handling hummingbirds is to check and see if it already has a band on its leg. At this point, the bird’s feet are clinging to the bag. When taken out of the bag, the bird retracts it feet close to its body. For this reason, it’s less stressful for it and less likely to do any harm to check the band before taking it out of the bag. If the hummer already has a band on its leg, it is called a recapture. When a recapture occurs, I give the band number to the recorder, who then writes it down on the data sheet. Then, I continue collecting data as I would with any other hummingbird. Data collected varies from species to species. If a recaptured bird does get way before I finish the data collection, I would know where the bird was from and where it had been because I already had the band number recorded.
Unbanded birds are just as important. They tell us about the species population, as well as its range. To band a bird correctly takes a lot of concentration. Banding pliers are used to see that the band is evenly applied and firmly closed all the way around. If it is not applied properly, the band could fall off, or worse, hurt the bird. The band could snag on something or scratch the bird’s leg. After I finish banding the bird, I take it out of the bag.
Proper handling is the key to banding safety. Since hummingbirds are so fragile, they stress more easily than other bird species. I must be gentle, but be able to study the bird. Certain holds must be used to have the ability to research and maneuver the bird, while causing no damage. Special instruments are used to get the most accurate measurements and statistics. Since hummers are so small, my instruments are small as well.
The ruler I use measures in millimeters. It measures the hummingbird’s wings and tail. I find the length of the wing and discern the shape of the feathers. To check the bird’s reservoir of stored fat, I blow through a straw to separate particular feathers on its throat and belly to avoid causing any damage. The fat is stored at the neck and is pretty easy to spot. The bill is measured in millimeters with a calibrator. The dial it has allows me to measure accurately. To check if the bird is young or not, I check for grooves on the bill and buff-like color on the back feathers. Using a high-powered magnifying head set, I can see the groove and buff more easily. The grooves on the bill are tiny notches that run down a certain amount of the bill’s length. The fewer the grooves a hummer has, the older it is. The same concept goes for the buff in the back feathers. The amounts of gray shown on the tips of the feathers tell me about the bird’s age: the grayer, the older the bird; the more buff, the younger the bird.
The last thing to check is the hummingbird’s weight. Weight is the result of many factors. The hummer’s fat amount, molt, feather wear, and stress level all contribute.
The scale I use to weigh the bird measures in grams. To weigh a hummingbird, I place it in a piece of fabric, closed by a small clip. After the weighing is over, I hold the bird up to the feeder. The hummer refuels by replenishing its supply of nectar, which was decreased by the banding process.
A good sign to see is pollen on the bird’s beak and crown. Since not all flowers bloom at the same time or have the same color pollen, the recording of the fact that pollen was found on the bird, coupled with the location of the banding station and the time of year, help determine which flowers hummingbirds use for food. We can then determine the flight corridors of certain species by the blossoming flower trail that they follow during migration.
It’s amazing to see the mysteries and complexities of such a small bird. Although hummingbird banding continues to reveal much about the lives of hummers, there is still much to discover and understand. If you are interested in learning more about, or actually observing banding in action, email me at email@example.com.