“Oooh, yes I know,” says Jackie Hancock, wildlife biologist, as she approaches a tangled gray bundle of feathers in a barely visible mist net. She deftly and patiently unravels the small but vocal oak titmouse from the thin mesh. The bird’s harsh squawks fade into a sweet, thin “dee dee dee” more typical of its normal calls. Hancock laughs at the contrast as she extricates it and places it into a white cotton bag for its trip to the banding station.
Catching songbirds is a familiar routine to Hancock and the Fort Hunter Liggett wildlife biologists, whose field work of this type is part of the Environmental Division’s broad mission.
"One of the Army's goals is to conserve biodiversity," said Hancock. "One of the benefits for mission readiness is to have a natural landscape. We maintain our natural resources for the Army training requirements, and we work with federal laws such as the Endangered Species Act, and National Environmental Policy Act."
Data collected through bird banding provides vital information on the health of avian populations and their habitats. These data are used to track trends in population numbers and help inform natural resources management decisions.
This station has been run for nearly 20 years in the same location. Both Hancock and biologist Darlene Woodbury had banding experience prior to coming to the installation, and count Kim Guilliam and Andy Lawrence among the expert banding team. Approximately every 10 days from May through August the banding station is busy, beginning at 6 a.m. when the birds are most active. Due to COVID-19 the crew now wears face coverings while at the banding table.
Known as MAPS (Monitoring Avian Productivity and Survivorship), the station is typical of hundreds of bird-banding stations across the country, with strict protocols as to net placements and bird handling, from the “bander’s grip” that keeps the bird in a loose but firm handhold, to the meticulous record-keeping, and to the aluminum bracelet each bird will ideally wear for the rest of its life.
To begin the process, birds are weighed, then a proper-sized numbered USGS band is slipped out of a film canister and readied. Hancock jokes that young folks in the digital age may not recognize those black canisters with gray lids. The silver bands are arrayed in sequential order on a wire and fed through a hole poked in the lid. The Pyle Identification Guide to North American Birds, the bird bander’s “bible,” tells what size band to use, and aids in detailed identification.
“First thing we do is attach a band,” said Hancock. “That way if the bird gets away at least we have the band and we know what number it is.”
That number is recorded with the USGS, which maintains a website for reporting band numbers. (https://www.pwrc.usgs.gov/BBL/bblretrv/)
If the bird is ever found (dead or alive), the band number will tell where and when the bird was banded and can provide information as to its age, migration patterns, and overall health. Sometimes the same birds are recaptured by the FHL team, adding to their database of information on the species. Indeed, the intent is to recapture previously banded birds, which account for about a quarter of birds netted. Recaptures are critical for evaluating survivorship of individuals.
The bird is taken from the bag and the band is carefully closed around the leg using specialized pliers. The next step is to determine the bird’s sex and amount of body fat, so the bander blows on its abdomen to move the feathers out of the way. Lawrence, the newest member of the team, processes a house wren and determines it’s either a female or a juvenile “hatch year” bird based on the absence of feathers (incubating birds remove their feathers to increase heat on the eggs). However, he suspects the latter because it still has some of the yellow edges on the bill. He wets the head feathers to move them away from the skull and looks for ossification of the bone surface. With Hancock’s help, he determines it is a juvenile.
After the wren has its wing measured and other data taken, Hancock shows how the feathers are richly colored and fresh, versus the worn look of an adult bird that’s had its feathers all season. “Yeah, this is a baby bird,” she agrees. “Birds have what we call a cheap set of feathers when they hatch out of the nest because they’re going to molt these out in the fall,” she explained. “So, there’s not a lot of production into these feathers.” She opens her hands and the house wren flies away, none the worse for wear.
Hancock manages the FHL Threatened and Endangered Species program, which includes the arroyo toad, purple amole plant, and San Joaquin kit fox, among others. The biologists are hoping to see the return of the federally endangered least Bell’s vireo to their station.
“One of the best ways to track the health of landscapes, especially riparian corridors, is through bird banding,” said Hancock. “We get a lot of information with our recapture data on how many birds are coming back, how long are they living, and we get an idea of how many hatch year birds are in the area.
And with a record number of birds banded this season, she says enthusiastically, “We’re doing pretty good!” Among the birds banded that morning included bushtits, Nuttall’s woodpeckers, ash-throated flycatchers, house and Bewick’s wrens, oak titmouse, and white-breasted nuthatch.
As with many biological surveys conducted on the installation, they partner with other governmental and scientific organizations to share information. The Institute for Bird Populations requested tail feathers from migratory birds to assist in a genomics study in collaboration with the University of California, Los Angeles. In prior years it was also done to ascertain the prevalence of West Nile virus.
When an ash-throated flycatcher was caught, Hancock removed an inner and outer tail feather and placed them in a small manila envelope, to be sent to the university. Then she releases the bird and leaves to once again to check her nets.
“One of the great things about this job is it’s so diverse,” she says animatedly. “We have programs that work with mammals, reptiles, amphibians and birds, and I get to work with all of them. I like supporting our biological community. I absolutely have a strong passion for the conservation of it. I feel I’m making a difference to help manage for these species that can thrive in this environment alongside the military. It’s amazing how compatible the two can be.”