He’d only been parked along the dirt stretch known as Vireo Alley, for a short time when he netted his first black-capped vireo of the day.
The fine mist net stretched between a cluster of short junipers, a short distance away from where Cimprich was perched.
“Usually we take advantage of the fact that these birds are territorial and the males will defend their territory by playing song,” he said.
Knowing where the nests were, Cimprich played a digital recording of a black-capped vireo “scolding” - a sound they make when any predator comes near their nest - and then he waited.
It didn’t talk long - about four minutes - for Cimprich to spot a vireo flutter onto the branches of a short juniper. It had come to investigate the commotion.
He watched as the small bird looked and listened, then he turned up the volume and watched the bird fly toward the scolding and into the mist net.
He quickly untangled the bird and placed it in a small cotton bag until the creature could be banded and released back into the wild.
The bands, which help scientists like Cimprish identify the migration habits of the birds, also help conservation specialists better understand endangered species and migratory birds.
A few minutes later, Cimprich reached into the bag and gently retrieved the vireo.
He clamped a series of colored metal bands on the bird’s legs, slightly above each of the talons, then measured the male vireo’s wingspan with a small ruler before holding him up.
The bird, ever defiant of his captor, “scolded” Cimprich.
“That’s 9 grams of fury,” Cimprich joked as he gently held the bird.
Cimprich smiled and concluded his examination, placing the bird in a small tube to be weighed.
Cimprich was wrong.
This black-capped vireo weighed 8.1 grams, less than the weight of his mechanical pencil.
Cimprich picked up the tube and uncapped the end, allowing the small bird to see the light of day again, and fly back to his mate and fledglings.
History
The Nature Conservancy has been a part of Fort Hood since 1992, but the relationship that exists today began 39 years earlier, in 1970. Then-III Corps commander Lt. Gen. Beverly Powell provided 4,466 acres of land as habitat for endangered species.
And according to Gil Eckrich, outreach coordinator for the Conservancy, Powell made that move before he was legally required - three years before the Endangered Species Act became law in 1973.
Powell might never had made the designation if it were not for the work of noted ornithologist Warren Pulich, who’d traveled to Fort Hood to find endangered species and urged Powell to designate the land to protect the birds.
Twenty years after the Endangered Species Act was made into law, the Army approached the Nature Conservancy about a partnership.
The species that led to the alliance of military and conservation are today listed as endangered - the golden-cheeked warbler in 1990 and the black-capped vireo in 1987.
To date, they are the only two endangered species that call Fort Hood home, and that makes the mission of the conservancy pretty important.
According to Dr. Rich Kostecke, project director for the Nature Conservancy, their mission is to help the Army with the research and management of endangered species. But that role has evolved to include others, such as vegetation conservation, land management, and the collection and preservation of artifacts and archaeological information.
The preservation of endangered species remains the priority of the organization, Kostecke said.
Feeling the burn
Although the Conservancy is tasked with protecting endangered species, there is only so much that can be done, and that is especially true when habitat is threatened by wildfires.
In April, more than 5,000 acres of prime vegetation burned during a training incident.
The fire also destroyed about 800 acres of vireo habitat and more than 300 acres of warbler habitat.
A similar wildfire erupted in February 1996, burning thousands of acres, although it was not as vast as the April wildfire,
While this could be considered catastrophic in some cases, conservationists on Fort Hood said that burning is a vital part of preserving and rebuilding habitat for species like these.
“People always have this image of these fires killing everything,” Eckrich said. “Sometimes, it’s a good thing.”
Kostecke said burning some of those areas helps reduce the possibility of wildfires in other areas.
Some of these habitats can take as long as five years to regenerate to anything close to what it was before, but in the aftermath of the April fire, root re-sprouts from much of the scorched vegetation are beginning to make a comeback.
The enemy
While birds have obvious natural enemies - snakes, cats and other larger animals - it’s hard to imagine birds being enemies to the vireo and warbler.
For almost as long as conservationist have been working to increase the population by monitoring their activities, they have been working to remove the female cowbird from the post.
The female cowbird is notorious, Eckrich said, for laying its eggs in warbler and vireo nests, which chases these smaller birds away.
“These birds are like women in a Killeen bar,” Eckrich said. “She attracts so many suitors.”
The female cowbirds scout their area and move in for the kill, he said.To combat the problem, the conservancy has set up numerous cowbird traps on post to trap these birds.
“The females are euthanized,” Kostecke said.
The males, on the other hand, are banded and released back into the wild.
Some of the traps are 4 feet wide by 8 feet long, but others are larger - 16 feet by 16 feet.
Eckrich, who helped design the traps years before, said he once removed more than 600 female cowbirds from one trap in a single month.
The Golden Cheeked Warbler
Several miles up the road, and a short distance from Vireo Alley, Becky Peak was packing up to leave her research site.
“We didn’t catch any today, but we caught four yesterday,” she said
Her luck at bagging and banding golden cheeked warbler hadn’t been as fruitful since many of the species have since migrated south to Mexico or Central America.
“There is still breeding activity with the golden cheeked, but for the most part many have had a successful nest. So now they are just taking care of their young after they leave the nest, or some are still trying, but they are few and far between,” Peak said. “It’s kind of winding down.”
By the end of June, nearly all the golden cheeked warblers that come to Fort Hood to nest will have since gone south for the winter.
However, Peak has a pretty good idea how the population is doing.
“My guess is that this year won’t be any different than the previous seven,” she said.
That’s because in 2002, the population seemed to plateau and has since remained pretty steady, which is good for an endangered species.
“A plateau is not necessarily a bad thing,” Kostecke said. “The habitat can only support so may birds.”
The Conservancy began monitoring the population of the warbler in 1992 and has seen a steady increase over a 10-year period.
“We have more now than we have previously,” she said. “It’s a cacophony of sound in comparison to other places where we go and do survey work. You can stand at a point for a while and hear nothing, whereas here, that’s an oddity.”
While the golden cheeked birds were harder to find, they were still there.
Peak monitored one small nest high up in a juniper tree where a golden cheeked male landed, grasping breakfast in his tiny beak and fluttering to the edge of his nest.
Peak’s smile broke beneath her binoculars as she peered upward.
“He’s such a good daddy,” she said.
End of the road, or just the start?
Several minutes later, Eckrich and Kostecke loaded up and began the trek back to the Conservancy offices near III Corps Headquarters.
Kostecke talked about the good working relationship between the post and the Conservancy, and how he hopes the relationship continues for many years.
“As long as they keep throwing money at us, we’ll keep researching,” Kostecke said.
Editor’s note: This is the second in an occasional series on The Natural Conservancy and Fort Hood’s ongoing conservation efforts.
