Science Spotlight

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  • January 24, 2019

Owl in flightShort Eared Owl. Courtesy of the National Digital Library.

Owl on snowy groundShort Eared Owl. Courtesy of the National Digital Library.

Owl perched on wooden fence post for barbed wire fence.Short Eared Owl. Courtesy of the National Digital Library.

Owl on snow-covered ground with low bush in foregroundShort Eared Owl. Courtesy of the National Digital Library.

A team of raptor biologists is working on a study of western populations of the Short-eared Owl – and are inviting members of the public to help collect and contribute important data as “citizen scientists.”

The project, known as the Western Asio Flammeus Landscape Study (WAfLS), is being conducted across eight western states, including Idaho, Montana, Nevada, Oregon, Utah, Washington and Wyoming, in addition to California. The purpose of the study is to determine the reasons for the sharp decline in Short-eared Owl populations – more than 60 percent over the last four decades across their western range.

“This project is a really unique and exciting collaborative effort to understand the species population on a very large scale,” said Carie Battistone, CDFW’s raptor biologist and WAfLS’ California State Volunteer Coordinator. “Given how wide-ranging – and in some cases, remote – the owls’ habitat is, we rely heavily on volunteers to help us collect the data we need.”

Battistone added that no special knowledge of raptors is needed in order for individuals to participate and contribute. “You don’t need to be a bird expert. You just need to have a keen interest in the outdoors and for the wildlife species that call California home,” she said.

The WAfLS project identifies 54 survey routes in California, all located within known habitat of the Short-eared Owl. “Citizen scientist” volunteers are needed to drive these routes, stop every ½ mile to look for and record owl presence and habitat features at each point. Volunteers will be asked to conduct two separate surveys on days of their choice during specified three-week survey windows in March through May. Each survey takes about 90 minutes and must be conducted during specified twilight hours, when the owls typically conduct their elaborate courtship displays.

Survey grids are located throughout much of the state from Modoc County in the north, Humboldt County in the west, Santa Barbara and Kern counties in the south and Mono County in the east. To view a map showing the grids for which volunteers are still needed, please visit the WAfLS website and click on “sign-up” on the right. The website also has a wealth of information on the project’s goals, as well as past reports, maps and volunteer resources (protocol, data sheets, etc.).

Battistone said that the information gathered by citizen scientists will be used by conservation experts and managers to design and implement strategies to help bolster populations of the Short-eared Owl.

“The project will help to determine what the Short-eared population numbers are like across the west, quantify how populations fluctuate spatially and temporally and identify how various factors – such as distribution, farming practices, grazing and climate – influence owls,” she said. “Once we have the data and resulting analyses in hand, we can make informed decisions on how to best protect and conserve the species.”

Owl photos courtesy of the National Digital Library. Top Photo: SEOW Survey: Surveying for Short-eared Owls can be a fun family activity. (CDFW Photo by Carrie Battistone.)

Media contact:
Kirsten Macintyre, CDFW Communications, (916) 322-8988

Categories: Wildlife Research
  • January 18, 2019

Four men and large fishing nets on small fishing boat on water. Marina and levy in background.
Joe Millosovich, an environmental scientist who specializes in lake and fisheries management in the Central Valley, came all the way from Fresno to captain one of the electrofishing boats collecting bass in the Delta Jan. 16. Several of CDFW’s biologists participating in the outing called it one of their favorite days of the year.

Man wearing gray camo foul weather gear, backward ball cap, and black life vest with yellow reflectors behind helm on fishing boat on water. Cloudy skies and grass-covered levy in background
Max Fish, an environmental scientist with CDFW’s Inland Fisheries Program, captained the electrofishing boat that collected the largest largemouth bass of the morning – a 10-pound-plus whopper.

Man wearing blue foul weather gear, blue ball cap, on docked fishing boat holding up two large fish. Water, land, and trees in background.
Kyle Murphy, a senior environmental scientist with CDFW’s Inland Fisheries Program, shows off two of the larger Delta largemouth bass headed for the International Sportsmen’s Exposition demonstration tank in Sacramento.

Among the more popular attractions at the Sacramento International Sportsmen’s Expo each January is the Western Bass Aquarium Demo Tank. The 6,000-gallon aquarium displays dozens of trophy largemouth bass collected by CDFW biologists from the Sacramento-San Joaquin Delta. The aquarium demo tank, with bleachers on both sides, is where professional bass anglers lead seminars demonstrating the latest techniques and can’t-miss lures – all without hooks attached so as not to injure the fish.

“This is the best display of largemouth bass anywhere in the country,” said Kent Brown, the longtime host of the ISE demonstration tank. “And that’s not just me talking. That’s from tournament bass fishermen who travel all over the country. There’s just no bass anywhere that can rival these Delta bass.”

The tank is also a tremendous source of pride for the CDFW fisheries biologists tasked with collecting the fish.

“It’s great for people to see the kind of fish they can catch here in their own backyard,” says Ben Ewing, a CDFW district fisheries biologist who headed the ISE collection effort this year. “All the fish get released back into the Delta immediately after the show and literally are available for anyone with a fishing license to catch.”

A mix of 16 fisheries biologists and volunteers assembled along the Delta near Stockton the morning of Jan. 16, the day before the opening of the four-day ISE show at Sacramento’s Cal Expo. They climbed onto four electrofishing boats to probe likely largemouth hideouts – tule stands, rip-rap shoreline, sunken boats, submerged tree limbs and other structure.

“We all come together to try and make a good display for the public,” Ewing said.

Over the years, a friendly competition has developed. A trophy and bragging rights go to the CDFW boat captain who collects the largest bass for the show. Each of the four captains took off with their crews in different directions searching for a largemouth bass that might not only win the day but one that might top their all-time ISE show record fish of more than 13 pounds.

The boats sent targeted currents of electricity through the water while crew members standing on the bow were ready with nets to scoop up the stunned fish for deposit into the live wells for safekeeping. In more than 20 years of providing Delta largemouth bass for the Sacramento ISE show, CDFW biologists have refined their methods and strategies.

In addition to looking for the largest fish, a mix of sizes is collected. Smaller bass add perspective in the tank and make the biggest fish look even bigger. Suckers, catfish and large sunfish add some fun diversity to the display. Striped bass are a no-go – they don’t do so well in transport and they’ve been known to jump out of the aquarium.

Max Fish, an environmental scientist with CDFW’s Inland Fisheries Program, piloted one of the electrofishing boats. He explained how these vessels are important research tools that allows CDFW scientists to survey fish populations and assess health in the state’s lakes and reservoirs. CDFW puts one of the boats on display at the ISE show each year and points out the connection between the boat and the bass in the tank.

On that overcast January morning with major winter storms looming in the forecast, Fish sent 340 volts of electric current through the shallow Delta waters. The conditions for electrofishing were nearly ideal – the plentiful organic material in the Delta helps conduct electricity while the overcast skies were unlikely to spook fish and send them deep beyond the boat’s effective reach.

Fish said the boat’s electric current ranges about 10 feet deep and about 20 feet wide – roughly the span between the two sets of anodes extending from the boat’s bow into the water.

Fish’s efforts were rewarded with the largest bass of the day – a 10.3-pound lunker among others in the 9- and 8-pound class. After congratulations, photos and good-natured ribbing from his colleagues back at the dock, the 60 or so fish collected by all the boats were shuttled directly to Sacramento’s ISE show in an aerated live well.

Meeting them there was CDFW veterinarian and fish pathologist Keven Kwak, who tested and treated the aquarium’s water to make sure it was safe for what would be the fish’s short, but celebrated stay in Sacramento.

CDFW Photos. Top Photo: CDFW biologists stand ready with nets in hand to scoop up temporarily stunned fish for the ISE’s bass fishing demonstration tank in Sacramento. Biologists look for the biggest and best specimens to showcase the Delta fishery. While the biologists are targeting largemouth bass primarily, the electric current brings up carp, catfish, suckers, striped bass and all manner of sunfish. Within a minute or two, the stunned fish come to and swim off.

Media Contact:
Peter Tira, CDFW Communications, (916) 322-8908

Categories: General