'They just showed up'

Once described by explorers as the ‘most abundant bird species in coastal southern California,’ tricolored blackbird populations are in sharp decline due to habitat loss.  This year, however, they found nesting spots on five national wildlife refuges throughout northern California and the central valley. "They came later than normal this breeding season, but it’s pretty exciting because they haven’t nested here in four years," said Geoffrey Grisdale, wildlife biologist at Kern National Wildlife Refuge in Delano, California.Credit: Geoffrey Grisdale/USFWS

Thousands of tricolored blackbirds nest on California wildlife refuges

By Byrhonda Lyons
September 22, 2017

This summer while many Californians were celebrating the end of the years-long drought, tricolored blackbirds were finding nesting spots on five national wildlife refuges throughout northern California and the central valley.

Scientists and citizens across the country use leg bands to identify birds. The U.S. Geological Survey hosts a website for the public to report banded birds they encounter. Credit: Geoffrey Grigsdale/USFWS

"They just showed up," said Geoffrey Grisdale, wildlife biologist at Kern National Wildlife Refuge in Delano, California. "They came later than normal this breeding season, but it’s pretty exciting because they haven’t nested here in four years."

Once described by explorers as 'the most abundant bird species in coastal southern California,’ tricolored blackbird populations are now in sharp decline due to habitat loss. Over the past 70 years, their population has decreased by 80 percent. The species is under review for protection under the Endangered Species Act (ESA).

Kern and other National Wildlife Refuges in California are working against the clock to increase nesting habitat and up tricolored blackbird populations now.

"If we wait until they are gone, then it’s too late," Grisdale said. "We’re doing the hard work now to make sure they don’t get to that point."

Tricolored blackbirds are medium-sized birds with white and red epaulettes on their wings. Adult males are glossy black, often with an iridescent blue-green sheen in bright sunlight. Adult females are dark brown with dark gray and brown streaks. They are not migratory, but they move around within lower elevation sites, and live and nest in California.

Biologists from Kern National Wildlife Refuge paddle to one of the tricolored blackbird colonies on Kern National Wildlife Refuge. This sprng and summer, tricolored blackbirds established nesting colonies on Merced, Colusa, Delevan, Bitter Creek and Kern National Wildlife Refuges. Credit: Geoffrey Grigsdale /USFWS

"The tricolored blackbird is important because it’s our bird," said Bob Meese, Ph.D., staff researcher at the University of California at Davis. "If Californians don’t care about [the bird], no one else is going to come and bail us out."

Getting Everyone Involved

It was nearly 13 years ago when Meese was asked to help with research on tricolored blackbirds.

Tools of the job: Leg bands, pliers, scales and other items are laid across the banding table. Credit: Geoffrey Grigsdale/USFWS

"When I started working with tricolored blackbirds, I wanted to improve our methods to detect colonies and sought to find them in places that had not been found before," he said. "My focus was on detecting tricolored blackbird colonies and improving data management."

Every three years since the late 1980s, there’s a statewide tricolored blackbird survey. This year nearly 200 people—an all-time high—went out and counted tricolored blackbirds in California. Volunteers documented where and when they saw tricolored blackbirds, providing an estimate of the number of birds throughout California and added their findings to a statewide online database called the Tricolored Blackbird Portal.

Having an online database is a huge improvement from where things were just 10 years ago. "Before the portal, people put their notes in field notebooks," Meese said.

Funded by the U.S. Fish and Wildlife Service, the portal has been active since 2007. It’s used by hundreds of scientists and concerned citizens who enter records of their observations, adding to scientists’ knowledge of the birds.

Migratory bird biologist Tracy Borneman (left) bands a tricolored blackbird as Greg Yarris, science coordinator for the Central Valley Joint Venture, observes.  Credit: Pam Bierce/USFWS

"The statewide survey depends upon the efforts of local experts," Meese said. "To illustrate, there was a dramatic increase in information in San Benito County this year, which I call the 'Debi Sheawater effect.'

"She’s an extremely good birder who was the volunteer coordinator in San Benito County," he said. "She’s a bird expert, and this year she counted 15,000 birds and added five additional blackbird locations that we didn’t know existed. All of that information is now in the portal and it’s helped plug a gap in our knowledge of the species."

Biologists Jennifer Brown and Greg Yarris attach a leg band to a blackbird. Every three years since the late 1980s, there’s a statewide tricolored blackbird survey. This year nearly 200 people—an all-time high—participated in the tricolored blackbird surevey in California. Credit: Pam Bierce/USFWS

In addition, the portal helps scientists track birds that are on the move throughout California. How do they keep track of the birds? They use tiny, metal bands known as bird bands.

Banding

By the time the sun rose, the Service’s biologists had already added bands to a dozen birds. But they had a long way to go before it got too hot and they had to shut down for the day. With a medium-sized, wire mesh walk-in trap and a bowl of cracked corn, Service bird biologist Jennifer Brown walked through the tall, scratchy grass to set the trap. She set the wire trap on the ground and headed back towards her lawn chair and binoculars.

Every few minutes, she grabbed her binoculars, counting the number of birds that were flying near the trap. After more than a few glances, she headed back towards the trap. The corn: gone. The trap: filled with small tricolored blackbirds that would soon be banded and released.

Scientists and citizens across the country use the bands to identify birds that may be a long way from home. In fact, the U.S. Geological Survey (USGS) has a website for the public to report banded birds they encounter.

As for tricolored blackbirds in California, "Since 2007, we’ve banded over 81,000 tricolored blackbirds," said Meese. "And many of these have been banded with Service staff and on refuges."

But banding birds is just one part of what refuges are doing to increase the birds’ population.

Colonies on Refuges

Tricolored blackbirds established nesting colonies on Merced, Colusa, Delevan, Bitter Creek and Kern National Wildlife Refuges this spring and summer. While nesting colonies on the refuge are not anything new, it is a testament to how important building habitat is to conserving tricolored blackbird populations in California.

A simple "walk in" trap baited with cracked corn.  "Since 2007, we’ve banded over 81,000 tricolored blackbirds," said Bob Meese, staff researcher at UC Davis. Many of these have been banded by Service staff on national wildlife refuges. Credit: Geoffrey Grisdale/USFWS

"Delevan had one of the largest tricolored blackbird colonies in the state this year," said Michael D'Errico, supervisory biologist at the Sacramento National Wildlife Refuge Complex. Delevan had 20,000 blackbirds on the refuge this year. There were 15,000 at Colusa.

Tricolored blackbirds usually start showing up to the refuges in the late spring, early summer. To make sure they have nesting habitat, refuge staff begin planning for the birds months—sometimes years—in advance.

"At Delevan, we did habitat enhancement last year," said Craig Isola, deputy project leader at Sacramento National Wildlife Refuge Complex. The wetland enhancement included burning and disking old decadent stands of cattails and excavating interconnecting channels and potholes to provide open water.

Service biologist Sabrina West retrieving a bird that would soon be banded. Credit: Byrhonda Lyons/USFWS

"We burned cattails, did some disking excavation, and because of all of the rain this year, we had more open water and fresh new cattail growth," D’Errico said. "The habitat conditions were just right for them [tricolored blackbirds] to decide to settle down and make a go of it."

"We’re not just putting up a refuge sign," Isola said. "We are managing the refuge for all kinds of wildlife—including tricolored blackbirds."

However, it’s not just happening at the Sacramento Complex. At Merced National Wildlife Refuge, the sentiment is the same, although bird numbers were down this year compared to other years.

"Tricolored numbers on our refuge are habitat-driven," said Kyle Whiteaker, equipment operator at Merced National Wildlife Refuge. "This year, the areas where they used to nest were completely underwater last year, so that may be a factor in the lower-than-average number of birds on the refuge."

Although there was a decline in tricolored blackbirds nesting on Merced National Wildlife Refuge, the birds were still in the neighborhood finding habitat in private silage fields—which can be a problem for the birds and for the landowners.

Working Together

When tricolored blackbirds nest on farms, they head straight for dairy farmers’ silage fields. Silage is primarily grains that are used to feed animals. Birds like to nest in the silage fields and farmers cut silage to feed their cattle.

State partner, Carie Battistone, raptor coordnator for the California Department of Fish and Wildlife, holds a recently banded tricolored blackbird. Credit: Pam Bierce/USFWS

"The weeks overlap," said Jesse Bahm, area biologist for the Natural Resources Conservation Service (NRCS). "The time to get the best yield for silage is at the same time tricolored blackbirds have young in the nest that are still growing their feathers and unable to fly."

In an ideal world, the birds would nest on the federally protected wetlands, instead of private lands. However, it’s impossible to order the birds off of private lands. The Service and other government agencies are addressing this by creating more protected wetlands, hoping to lure the birds to better habitat.

NRCS is establishing wetland habitat for tricolors on more than 400 acres of wetlands through conservation easements. NRCS also provides cost-share to landowners who wait until after the tricolored blackbirds have left to cut their silage.

In addition, the Service, NRCS, Western United Dairymen, California Audubon, California Department of Fish and Game and other partners have formed a working group to develop strategies and working plans to conserve tricolored blackbird habitat.

Tricolored blackbird chicks from a colony at Kern National Wildlife Refuge. Credit: Geoffey Grigsdale/USFWS

"We’re trying to do anything we can to help tricolored blackbirds," said Matt Hamman, California state coordinator for the Service’s Partners for Fish and Wildlife Program (Partners). The partners program works with private landowners to implement conservation practices on private lands. "We often step in with other organizations to shore up some of the costs of creating wetlands in the Valley."

"I work one-on-one with producers, and I like to educate them about tricolored blackbirds and build that trust," Bahm said. "If you just worry about regulations, people are apprehensive. I focus on the benefits to the birds and to the landowners."

Since the NRCS program began four years ago, farmers have helped save more than 200,000 birds. According to this year’s survey, there were 177,000 tricolored blackbirds in California in 2017. In 2014, the count was 145,000. And in 2011, scientists counted 259,000 birds.

The tricolored blackbird population may continue to fluctuate, but the working group and concerned citizens are still coming together to find ways to keep tricolored blackbirds around for generations to come.

"If we want to succeed, it’s going to take everyone," Meese said. "It’s our bird. It’s California’s blackbird. And no one is going to come in and do the work for us."

Tricolored blackbirds awaiting their bands in Folsom, California. This year, the Service banded about 700 birds in Folsom. They've been coming to the same site for about 30 years. "The tricolored blackbird is important because it’s our bird," said Bob Meese, Ph.D., staff researcher at the University of California at Davis. "If Californians don’t care about [the bird], no one else is going to come and bail us out." Credit: Pam Bierce/USFWS

 

Byrhonda Lyons is a public affairs specialist and the regional social media coordinator for the Pacific Southwest Region, located in Sacramento, California. She writes, "tweets" and posts daily about the activities of the U.S. Fish and Wildlife Service in California, Nevada and the Klamath Basin.