2011-06-05 "Birders swoop in to aid 'threatened' hawks at construction site near Vacaville" by Tony Burchyns from "Vallejo Times-Herald" newspaper
VACAVILLE -- For some, protecting the environment is for the birds. But local hawk experts might take that as a compliment.
Especially those grabbing binoculars and rearranging their schedules to monitor a Swainson's hawk nest near a construction site outside of Vacaville.
The bird species is listed as "threatened" under the California Endangered Species Act.
"Birders are dedicated people," said James Walsh, of Fairfield, who's part of a handful of volunteers from Vallejo to Sacramento to Santa Rosa. "Once you get hooked, it's like a drug."
Their concern deals with Vacaville's construction of new wastewater plant facilities, expansion of existing buildings and demolition of other structures at 6040 Vaca Station Road, in the unincorporated hamlet of Elmira.
Two-year project -
The work is expected to start this month, and wrap up in spring 2013, according to Vacaville's public works department. The project is meant to improve the quality of water discharged into Old Alamo Creek, a tributary of the Sacramento-San Joaquin Delta.
But California Department of Fish and Game records show several documented Swainson's hawk nest sites within a half-mile of the project area.
And on May 23, a city-commissioned biologist pinpointed an active nest within a eucalyptus tree on a farm just 820 feet northeast of the site. A Swainson's hawk was seen flying into the nest, remaining there for five minutes and leaving to forage in the agricultural field east of Lewis Road, project documents show. A hawk was also seen leaving the nest the next day, May 24.
Meanwhile, a second raptor's nest was spotted in a eucalyptus tree adjacent to the site's northwest boundary. However, the nest did not appear to be occupied, the biologist reported.
A third nest, roughly 1,300 feet from the site, was observed on May 24. It was monitored for an hour, but no hawks were seen.
However, the two-day survey concluded there is at least one active nest within 1/4 mile of planned construction activities.
'Appropriate buffers' -
As a result, the city has begun working with Fish and Game to establish "appropriate buffers," develop measures to avoid nest disturbance and launch a monitoring and reporting program before the work begins. Another round of nest surveys will be conducted on June 13 and 14.
"We have been working with Fish and Game since the beginning (of the project) regarding the hawks," said Deborah Faaborg, the city's environmental project manager. "We're confident that the mitigation and monitoring details we prepared are going to work."
In an April letter to Fish and Game, the city suggested that the hawks nesting in the area "have become well adapted" to human activities. It's generally accepted that the birds have become accustomed to living near people's homes in places like Sacramento.
Fish and Game officials and local hawk experts, however, say it cannot be assumed that these birds will tolerate the project's intensive noise levels and visual disturbance created from demolition and construction activities.
Also of concern is that a failed nesting attempt could cause a pair to not return to its nest site in future breeding seasons between March 1 and Sept. 15.
Courtship activities -
During an April 5 visit, a Fish and Game environmental scientist observed a pair of Swainson's hawks circling the large eucalyptus tree, and an adult hawk was seen flying out of this particular nest tree. The hawks' behavior suggested initiation of courtship or nesting activity, the scientist concluded.
Fish and Game has advised the city that if eggs or young birds are killed, shot, trapped or die by nest disturbance as a result of the project, it would be "illegal" under state law unless the city applies for a special permit.
Meanwhile, Walsh and about seven other volunteers are mobilizing to keep an eye on the nest -- and report any signs of distress to Fish and Game officials.
Walsh, 53, manages a Fairfield landscape company and leads people on hawk-watching tours and hikes through Lynch Canyon and the King-Swett Ranches. He's been a nature buff all his life.
"They are a threatened species," Walsh said of his motives. "One of the reasons why is ... the loss of nesting sites and human encroachment onto both their summer and wintering grounds (in South America)."
Eighty percent decline -
Once a relatively common species found throughout California's foothill grasslands, the Swainson's hawk population has declined more than 80 percent in recent decades, biologists say. The predatory birds are now restricted to portions of the Central Valley and Great Basin regions. Due to their significant drop in numbers, the hawks have been state-listed as "threatened" since 1983.
A 1979 Fish and Game survey found just 350 nesting pairs remaining in the state and determined this to be a 90 percent population reduction of the historic Swainson's hawk numbers.
Since 1980, several research efforts have added information on the hawks' ecology and distribution.
In a related move, an ad hoc committee of researchers and agency biologists was established in 1989 to advise regulators on land use issues affecting the species.
About 10 years ago, the committee estimated the nesting population to include between 700 and 1,000 breeding pairs, mostly in the Central Valley.
Other studies in the Sacramento Valley, however, suggest that this still may be an underestimate of the statewide population. A 2005-06 count estimated more than 2,000 breeding pairs, Fish and Game Environmental Program Manager Scott Wilson said.
But rapid urbanization and human population growth continue to place the hawk at the center of development controversies.
Walsh added, "I am not going to say all construction should be stopped because it is detrimental to the environment, but there has to be a middle ground in any situation."
'Hawk Watch Team' -
Another volunteer, Santa Rosa resident Larry Broderick, said he's been a raptor enthusiast for more than 20 years, studying them in college and doing various things to support birds of prey in general.
In his spare time, Broderick educates people on threats that directly affect hawks, falcons and eagles, including power lines, wind turbines, poachers, poisonings and habitat loss.
In the last six or seven years, Broderick, 44, a salesman at Donahue Truck Centers, has been taking people out on hawk watching tours and hikes with land trusts and Audubon groups.
Walsh participates in Broderick's West County Hawk Watch team, which includes a handful of other volunteer docents.
"I watch the hawks because they are an environmental barometer at the top of the food chain," Broderick said. "When something affects them, it won't be long until it affects us."
Broderick mentioned the harmful effects of the pesticide DDT on bald eagles and peregrine falcons before humans fully understood the dangers.
"Another reason why I am concerned about this particular pair of 'Swainies' is that the birds in the Yolo Basin have been having issues with finding nesting trees, with lots of nests being taken over by red-tailed hawks and herons," Broderick said. "Also, sudden oak death is doing a number on (their) traditional nesting sites."
Nesting site search -
Thirty years ago, Swainson's hawks had been driven out of their traditional Solano County breeding areas. But with their numbers on the rise, and fewer oaks and other big trees dotting the landscape in Yolo and other Central Valley counties, biologists say the hawks are re-establishing their old stomping grounds.
"So this pair is trying to strike out and find new habitat ... yet we are in jeopardy of driving them off with noise, tractors, dirt, dust and whatever else goes on at that site," Broderick said.
Walsh suggested that the $22.6 million project could be scheduled around the birds' nesting season.
But Vacaville is on a tight deadline.
The plant upgrade is one of four projects needed to meet the requirements of the city's National Pollutant Discharge Elimination System permit. Ordered in 2008, it will include adding facilities needed to meet the government's "denitrification" -- conversion of nitrate to nitrogen gas -- regulatory requirement by May 2013, as well as upgrades to improve plant operations.
Headworks will be modified, aeration basins expanded, a flow equalization basin constructed, an existing biosolids storage lagoon modified and a second standby generator added.
But minimizing harm to the hawks remains of high importance, Faaborg said. So far, the city's even considering holding an environmental education session for the construction team and appointing someone through Fish and Game to watch the nest three days a week during certain project phases.
Fish and Game officials are reviewing the plans, which include many other measures, but their approval is not required, Wilson said.
Meanwhile, members of the public are welcome to keep an eye on things, as long as they stay clear of the construction zone, Faaborg said.
"That's fine with us," she said.
Walsh said the group doesn't want to get in the way, but rather encourage maximum vigilance.
"I think the city is being sincere," he added. "It's in their best interest."
On the web:
For information about Solano County hawk watch tours, email Larry Broderick of West County Hawk Watch at firstname.lastname@example.org. Or, visit solanolandtrust.org and click on "Get Involved" or "Events Calendar."
Swainson's hawk at a glance:
* Scientific name: Buteo swainsoni
* Habitat: Open grasslands, prairies, farmlands and deserts. Winters in eastern Argentina, Paraguay and southern Brazil.
* Diet: California voles, gophers, ground squirrels, rabbits, birds, snakes, lizards, grasshoppers and other insects.
* Reproduction: Females typically lay two to three eggs a year. Breeding pairs mate for life. The oldest bird on record is 24 years old.
* Population: More than 2,000 breeding pairs and growing as of 2006. State-listed as "threatened" since 1983.
* Description: 17-22 inches long with a 4-4 1/2 foot wingspan. Weighs 1 1/2-2 1/2 pounds. Most birds are dark red with white chest and throat patches.