Anchor ads are not supported on this page.

4S Ranch Allied Gardens Alpine Baja Balboa Park Bankers Hill Barrio Logan Bay Ho Bay Park Black Mountain Ranch Blossom Valley Bonita Bonsall Borrego Springs Boulevard Campo Cardiff-by-the-Sea Carlsbad Carmel Mountain Carmel Valley Chollas View Chula Vista City College City Heights Clairemont College Area Coronado CSU San Marcos Cuyamaca College Del Cerro Del Mar Descanso Downtown San Diego Eastlake East Village El Cajon Emerald Hills Encanto Encinitas Escondido Fallbrook Fletcher Hills Golden Hill Grant Hill Grantville Grossmont College Guatay Harbor Island Hillcrest Imperial Beach Imperial Valley Jacumba Jamacha-Lomita Jamul Julian Kearny Mesa Kensington La Jolla Lakeside La Mesa Lemon Grove Leucadia Liberty Station Lincoln Acres Lincoln Park Linda Vista Little Italy Logan Heights Mesa College Midway District MiraCosta College Miramar Miramar College Mira Mesa Mission Beach Mission Hills Mission Valley Mountain View Mount Hope Mount Laguna National City Nestor Normal Heights North Park Oak Park Ocean Beach Oceanside Old Town Otay Mesa Pacific Beach Pala Palomar College Palomar Mountain Paradise Hills Pauma Valley Pine Valley Point Loma Point Loma Nazarene Potrero Poway Rainbow Ramona Rancho Bernardo Rancho Penasquitos Rancho San Diego Rancho Santa Fe Rolando San Carlos San Marcos San Onofre Santa Ysabel Santee San Ysidro Scripps Ranch SDSU Serra Mesa Shelltown Shelter Island Sherman Heights Skyline Solana Beach Sorrento Valley Southcrest South Park Southwestern College Spring Valley Stockton Talmadge Temecula Tierrasanta Tijuana UCSD University City University Heights USD Valencia Park Valley Center Vista Warner Springs

They haul meat

Golden eagle tracking project yields unexpected data

Since three local scientists studying golden eagles started trying to catch the birds in October — to swab them for DNA and pathogens and release them with a GPS transmitter attached — they've gone through 6800 pounds of bait meat.

"We've enhanced the landscape with three tons of food," said Robert Fisher. "It's a giant bird feeder — with cow."

Peter Bloom

Fisher, Jeff Tracey, and Peter Bloom are in the early stages of catching the eagles, gathering DNA to add to a broad western database of such eagles, and using the GPS data to track the birds. So far, the early data that shows the birds' location every 15 minutes already challenges our notions. These birds travel.

One sequence shows a bird that starts its day on Otay Mountain, travels north along the Sweetwater corridor to the San Diego River corridor, and on north until it reaches Palomar Mountain. And then the bird finds its way back to Otay Mountain in a day or two. Another heads north, avoiding Ramona, still making it all the way to Guejito Ranch.

Sponsored
Sponsored

All the data is early and inconclusive, since the study just began. But what the scientists have learned about the mechanics of doing such a study is surprising.

"A lot of science is people doing a lot of mundane things and hoping some glimmer of useful information will come from it," Tracey said. "Us? We're learning far more about hauling meat than we ever anticipated."

So far, they've caught seven birds — five females and two males — mostly in South County. Their goal is to catch and track 20. Golden eagles are civilization-shy. They hunt live prey, mostly rabbits and squirrels, but will eat carrion when prey is hard to find. They live about 30 years and stay with their mates for a long time, Tracey said. The birds like to keep territory and a network of nests within that territory.

Much of the information about where they've nested in the past was gathered by egg collectors — people who found the nests and took eggs, a method unthinkable by today's standard that probably contributed to the small numbers of birds now.

"There are 334 sets of [two] eggs that we know about that were collected [in San Diego] between 1884 and 1959," Fisher said. "We have no idea how many eggs were collected that weren't archived or put in a museum somewhere."

The new approach, of catching, attaching, and releasing the birds has its own risks.

"Golden eagles are super dangerous. They have really scary talons — a misstep and your guts are hanging out," Fisher said.

The team has been working mostly in South County, particularly around Otay Mountain.

"We're in meat management," Fisher says. "How do you keep meat on the landscape? Rebar." Tracey says the team sets up a rebar cage to hold the raw meat down and then, after they've watched the eagles eat in the spot a few times, a trap is sprung by someone watching the bait on remote camera. It takes time for eagles to see the spot as a reliable meal.

The birds only started dining at the traps in mid November, Tracey said. But other animals weren't so shy. Feral pigs cleaned out the bait by Barrett Lake. Pumas cleaned out another trap. Bobcats and skunks put in guest appearances.

"And hundreds of coyotes, of course," Fisher says. "We had to feed the coyotes as much as they could eat to get them to leave the bait alone."

The seven birds they've caught were healthy — if upset, Fisher said.

"We have watched pairs where we caught the female and the male saw it and it got really difficult to catch the male," he said. "We haven't caught as many as we want to."

The early travel data have been pretty surprising. The birds' territory appears to be far larger than expected, from 45 square miles to 340 square miles traveled by one of the females. And they avoid places, like Ramona.

"They stay in areas that have a high degree of wildness — the urban edge is really defining their territory, you can see it," Fisher says.

The latest copy of the Reader

Here's something you might be interested in.
Submit a free classified
or view all
Previous article

THEIR Lady of Guadalupe?

Racist attack in North Park after dark

Since three local scientists studying golden eagles started trying to catch the birds in October — to swab them for DNA and pathogens and release them with a GPS transmitter attached — they've gone through 6800 pounds of bait meat.

"We've enhanced the landscape with three tons of food," said Robert Fisher. "It's a giant bird feeder — with cow."

Peter Bloom

Fisher, Jeff Tracey, and Peter Bloom are in the early stages of catching the eagles, gathering DNA to add to a broad western database of such eagles, and using the GPS data to track the birds. So far, the early data that shows the birds' location every 15 minutes already challenges our notions. These birds travel.

One sequence shows a bird that starts its day on Otay Mountain, travels north along the Sweetwater corridor to the San Diego River corridor, and on north until it reaches Palomar Mountain. And then the bird finds its way back to Otay Mountain in a day or two. Another heads north, avoiding Ramona, still making it all the way to Guejito Ranch.

Sponsored
Sponsored

All the data is early and inconclusive, since the study just began. But what the scientists have learned about the mechanics of doing such a study is surprising.

"A lot of science is people doing a lot of mundane things and hoping some glimmer of useful information will come from it," Tracey said. "Us? We're learning far more about hauling meat than we ever anticipated."

So far, they've caught seven birds — five females and two males — mostly in South County. Their goal is to catch and track 20. Golden eagles are civilization-shy. They hunt live prey, mostly rabbits and squirrels, but will eat carrion when prey is hard to find. They live about 30 years and stay with their mates for a long time, Tracey said. The birds like to keep territory and a network of nests within that territory.

Much of the information about where they've nested in the past was gathered by egg collectors — people who found the nests and took eggs, a method unthinkable by today's standard that probably contributed to the small numbers of birds now.

"There are 334 sets of [two] eggs that we know about that were collected [in San Diego] between 1884 and 1959," Fisher said. "We have no idea how many eggs were collected that weren't archived or put in a museum somewhere."

The new approach, of catching, attaching, and releasing the birds has its own risks.

"Golden eagles are super dangerous. They have really scary talons — a misstep and your guts are hanging out," Fisher said.

The team has been working mostly in South County, particularly around Otay Mountain.

"We're in meat management," Fisher says. "How do you keep meat on the landscape? Rebar." Tracey says the team sets up a rebar cage to hold the raw meat down and then, after they've watched the eagles eat in the spot a few times, a trap is sprung by someone watching the bait on remote camera. It takes time for eagles to see the spot as a reliable meal.

The birds only started dining at the traps in mid November, Tracey said. But other animals weren't so shy. Feral pigs cleaned out the bait by Barrett Lake. Pumas cleaned out another trap. Bobcats and skunks put in guest appearances.

"And hundreds of coyotes, of course," Fisher says. "We had to feed the coyotes as much as they could eat to get them to leave the bait alone."

The seven birds they've caught were healthy — if upset, Fisher said.

"We have watched pairs where we caught the female and the male saw it and it got really difficult to catch the male," he said. "We haven't caught as many as we want to."

The early travel data have been pretty surprising. The birds' territory appears to be far larger than expected, from 45 square miles to 340 square miles traveled by one of the females. And they avoid places, like Ramona.

"They stay in areas that have a high degree of wildness — the urban edge is really defining their territory, you can see it," Fisher says.

Comments
Sponsored

The latest copy of the Reader

Here's something you might be interested in.
Submit a free classified
or view all
Previous article

East County militia remains on high alert after shooting down “manned” drone near border

Copter Op?
Next Article

Big Swell Rolls in for Christmas – Rockfish Closure

Big wahoo down south
Comments
Ask a Hipster — Advice you didn't know you needed Big Screen — Movie commentary Blurt — Music's inside track Booze News — San Diego spirits Classical Music — Immortal beauty Classifieds — Free and easy Cover Stories — Front-page features Drinks All Around — Bartenders' drink recipes Excerpts — Literary and spiritual excerpts Feast! — Food & drink reviews Feature Stories — Local news & stories Fishing Report — What’s getting hooked from ship and shore From the Archives — Spotlight on the past Golden Dreams — Talk of the town The Gonzo Report — Making the musical scene, or at least reporting from it Letters — Our inbox Movies@Home — Local movie buffs share favorites Movie Reviews — Our critics' picks and pans Musician Interviews — Up close with local artists Neighborhood News from Stringers — Hyperlocal news News Ticker — News & politics Obermeyer — San Diego politics illustrated Outdoors — Weekly changes in flora and fauna Overheard in San Diego — Eavesdropping illustrated Poetry — The old and the new Reader Travel — Travel section built by travelers Reading — The hunt for intellectuals Roam-O-Rama — SoCal's best hiking/biking trails San Diego Beer — Inside San Diego suds SD on the QT — Almost factual news Sheep and Goats — Places of worship Special Issues — The best of Street Style — San Diego streets have style Surf Diego — Real stories from those braving the waves Theater — On stage in San Diego this week Tin Fork — Silver spoon alternative Under the Radar — Matt Potter's undercover work Unforgettable — Long-ago San Diego Unreal Estate — San Diego's priciest pads Your Week — Daily event picks
4S Ranch Allied Gardens Alpine Baja Balboa Park Bankers Hill Barrio Logan Bay Ho Bay Park Black Mountain Ranch Blossom Valley Bonita Bonsall Borrego Springs Boulevard Campo Cardiff-by-the-Sea Carlsbad Carmel Mountain Carmel Valley Chollas View Chula Vista City College City Heights Clairemont College Area Coronado CSU San Marcos Cuyamaca College Del Cerro Del Mar Descanso Downtown San Diego Eastlake East Village El Cajon Emerald Hills Encanto Encinitas Escondido Fallbrook Fletcher Hills Golden Hill Grant Hill Grantville Grossmont College Guatay Harbor Island Hillcrest Imperial Beach Imperial Valley Jacumba Jamacha-Lomita Jamul Julian Kearny Mesa Kensington La Jolla Lakeside La Mesa Lemon Grove Leucadia Liberty Station Lincoln Acres Lincoln Park Linda Vista Little Italy Logan Heights Mesa College Midway District MiraCosta College Miramar Miramar College Mira Mesa Mission Beach Mission Hills Mission Valley Mountain View Mount Hope Mount Laguna National City Nestor Normal Heights North Park Oak Park Ocean Beach Oceanside Old Town Otay Mesa Pacific Beach Pala Palomar College Palomar Mountain Paradise Hills Pauma Valley Pine Valley Point Loma Point Loma Nazarene Potrero Poway Rainbow Ramona Rancho Bernardo Rancho Penasquitos Rancho San Diego Rancho Santa Fe Rolando San Carlos San Marcos San Onofre Santa Ysabel Santee San Ysidro Scripps Ranch SDSU Serra Mesa Shelltown Shelter Island Sherman Heights Skyline Solana Beach Sorrento Valley Southcrest South Park Southwestern College Spring Valley Stockton Talmadge Temecula Tierrasanta Tijuana UCSD University City University Heights USD Valencia Park Valley Center Vista Warner Springs
Close

Anchor ads are not supported on this page.

This Week’s Reader This Week’s Reader