Each spring, as the snows vanish from the high country and warmth returns to Southwest Colorado, color begins to flit across the sky in the form of hummingbirds making their pilgrimage back to local nesting grounds.
Swarming around bright red feeders filled with sweet liquid mimicking nectar, the birds provide hours of viewing pleasure for local residents. Tiny wings thump the air with a remarkable cadence, keeping the brilliant creatures afloat in the breeze as they dart to and fro, seeking their next meal from a garden flower or a conveniently placed feeder.
Yet despite their ubiquitous nature, as common in Colorado as the Columbine flower, researchers still have much to learn about the diminutive creatures and what they need to survive. And as habitats are threatened through development and climate change, researchers have become more eager to understand hummingbirds and their needs.
In an effort to create a more comprehensive picture of hummingbird behavior, the Hummingbird Monitoring Network has partnered with public land management agencies and volunteer groups to create monitoring stations across the country to gather more hummingbird data.
In Montezuma and Dolores counties, volunteers are taking turns adding to the body of knowledge on hummingbirds at monitoring stations at Mesa Verde National Park and the Dunton Guard Station, near Rico.
On June 5, a group of eight volunteers and two Bureau of Land Management employees met at the Dunton Guard Station to open the monitoring season and begin the tedious task of banding the birds that find their habitat in the nearby alpine meadows. This year marks the fifth season of hummingbird banding at Dunton.
We band birds here and do this year after year to see how many are coming back from Mexico each year and how many are surviving, said Darla Welty, a Mancos resident who is the bander for the Dunton project. This allows us to gain a general idea of how healthy they are and how various conditions are affecting the birds.
Hummingbirds are remarkably territorial, returning to the same nesting grounds year after year. This dedication to a certain habitat allows researchers to gather specific information and extrapolate behaviors and trends for larger populations.
Tracking individual birds allows researchers to use specific math calculations to determine how many are coming back each year and what the birds are doing in general, Welty said. The birds have such site fidelity we are able to gather information on specific birds each year.
Monitoring and banding activities at Dunton start at daylight. Two feeders stationed in the meadow sway gently in the morning breeze, the early sunlight glinting off the ruby surfaces and causing the netting fixed above the feeders to glow like halos. The nets are attached to strings that run back into the hands of volunteers stationed in lawn chairs nearly 10 yards from the feeders. When a single bird is at the feeder, the net is released, falling quickly around the feeder and preventing the small feathered creature from making a quick escape.
Armed with mesh bags, volunteers go to the feeder and delicately capture the colorful bird. The hummingbird is then transferred to the mesh bag and carried into the guard station at Dunton, formerly operated by the U.S. Forest Service. Once the bird is inside, Welty goes to work.
Fitted with lighted magnifying goggles, Welty uses calm and measured movements to remove the bird from the bag and begin gathering data.
Speaking softly to the birds, Welty spreads the wings to take measurements and notes various markings and gender.
I know pumpkin, we need to get you out of here, Welty murmurs to a female broad-tail hummingbird, which is clearly less than comfortable with the situation. In a firmer tone, Welty calls out information on the bird to data recorders Kathleen Turnbull and Phil Kemp, both of Dolores. Female broad-tail. Two iridescent feathers. No molting. She is with eggs.
Pollen samples are also taken from each bird. Judith Franklin, from Cortez, swipes the bill of each bird with a waxy substance to gather the pollen than examines the specimen under a microscope, comparing the sample with plant species collections from the area.
We want to get an idea of what they might be feeding on throughout the year, Franklin said.
The most important part of the data collection comes when Welty selects a tiny metal band to fit around the hummingbirds leg. The bands are used simply to track the birds from year to year. Because they are so small, the numbers on the bands can only be read under magnification. As a result, the bands only become significant when the birds are captured, either in the winter grounds in Mexico, or the following year, back in Dunton.
Due to their territorial nature, Welty said the volunteers have only ever captured one bird at Dunton, which was banded in another location. However, it is not unusual to recapture Duntons banded birds every year.
It helps us keep track of them and we are able to see they are coming back to the same place year after year, Welty said.
Once Welty finishes her examination, the bird is wrapped loosely in a piece of netting and placed on a scale. Rarely does a bird tip the scale at heavier than four ounces, most females weigh less than three ounces. Each piece of data is recorded to create a record of population health and behavior.
We get their weight and a general idea of how healthy they are, Welty said. This year we are looking at their feathers. It was a cold year in Mexico and some researchers thought that might affect the birds molt, so we check that.
When all the measurements are taken and Welty is satisfied with the amount of data captured, the birds are given a long drink of sugar water before Turnbull lifts them up to the window and allows them to take flight once again. The traps are then reopened and another bird is brought to Welty for its physical.
The volunteer group monitors hummingbirds at Dunton every other Tuesday through September. A typical season will see between 170 and 200 bird bandings, though far more birds visit the feeders each day.
At the end of the season, the data is turned over to researchers in hopes the Dunton hummers can help clarify some of the questions that still linger about the vibrant birds.
Volunteers at the June 5 banding included Darla Welty, Mancos; Phil Kemp, Dolores; Kathleen Turnbull, Dolores; Judith Franklin, Cortez; Melissa Margetts, Telluride; Barb Headley, Cortez; Mary Alexander, Dolores; Pat Hancock, rural Dolores County. Bureau of Land Management employees Pete Foote and Chris Jones were also at the site.
For more information, or to participate in a monitoring session, contact Welty at 533-7231.