Science Spotlight

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  • March 5, 2020

A wild turkey inside a cardboard box to keep it calm is weighed as CDFW Environmental Scientist Laura Cockrell records the data at the Upper Butte Basin Wildlife Area.
Environmental Scientist Laura Cockrell records the weight of a wild turkey at Little Dry Creek prior to banding.

A banded wild turkey’s two legs show off the two different type of bands CDFW biologists affix to the birds at the Upper Butte Basin Wildlife Area. One band is riveted closed; the other clamped close until its two butt-ends are touching.
Wild turkeys banded in 2019 and 2020 are given one traditional, butt-end band on one leg and one rivet band on the other.

Silvery metallic butt-end bands in the hand of CDFW environmental scientist Laura Cockrell.
Environmental Scientist Laura Cockrell shows off the supply of butt-end bands prior to banding.

Turkey hunters in parts of Butte and Glenn counties who are skilled and lucky enough to bag a tom this spring may be in for a pleasant surprise: Their bird may be sporting some jewelry – a band on each leg.

Since early February, CDFW biologists at the Upper Butte Basin Wildlife Area – supported by the National Wild Turkey Federation (NWTF) – have been busy trapping and double-banding wild turkeys at the wildlife area’s Howard Slough and Little Dry Creek units. So far this year, some 45 turkeys have been banded, which include toms, hens and young males known as “jakes.”

The staff and volunteers have just about a month and a half to trap and band all the wild turkeys they can between the close of the waterfowl hunting season and the start of the spring wild turkey season in mid-March. It’s part of an innovative research effort aimed at better understanding the characteristics, growth rates, habitat use, range and abundance of the growing population of wild turkeys using the wildlife area.

Bird bands long have been an important research tool for biologists and considered a prize among many hunters who are allowed to keep them after reporting the band information. The Upper Butte Basin turkey banding project is the only one of its kind in the state, making those turkey bands a rare commodity and a valuable potential data source.

In addition to the banding, the turkeys are weighed, sexed and measured at various points before being released.

The wild turkey study began at the wildlife area in 2015 along with the launch of limited spring wild turkey hunts there. NWTF helped secure grant funding to start the hunt program and initiate the research effort. The funds came from the sale of upland game bird hunting validations and stamps required of upland game bird hunters.

“We thought it would be great to start getting an abundance estimate for the turkeys that we do have out here to make sure that we weren’t harming the population through the hunt program and also to see how much hunter opportunity we could potentially utilize,” said Kevin Vella, NWTF’s district biologist for California, Nevada, Oregon and Washington.

The spring wild turkey hunt program has been so successful and popular over its short history funding for the program and its research component will continue under CDFW’s general budget moving forward.

“I think Howard Slough especially offers some of the best turkey hunting I’ve seen anywhere,” said Upper Butte Basin Wildlife Area Manager Tim Hermansen. “Certainly, youth hunters have an excellent opportunity out here.”

Spring turkey hunts at both the Howard Slough and Little Dry Creek units are limited to lottery drawings through CDFW’s website in order to ensure an uncrowded, high-quality hunting experience. The hunter quota and the turkey harvest both have grown over the years along with the local turkey population. Hunter success ranged from 30 to 60 percent during the 2019 spring season but reached 100 percent for the youth hunt at Howard Slough in 2018.

Back to those double-banded birds.

Although 101 turkeys were banded at the wildlife area between 2015 and 2019, only three banded turkeys have been reported by hunters. That leads biologists to believe most of the turkeys have been prying off the traditional, “butt-end” bird bands, which have two edges that butt evenly together when clamped on.

The NWTF has since supplied Upper Butte Basin with rivet bands that are made of a harder metal and riveted closed when attached. The turkeys banded in 2019 and 2020 now receive a butt-end bird band on one leg and a rivet band on the other. Any of those harvested birds wearing a single rivet band will confirm suspicions that the birds have been prying off the butt-end bands.

“That’s the downside of doing any kind of novel research,” explained Laura Cockrell, a CDFW environmental scientist based at the Upper Butte Basin. “You only have your own mistakes to learn from.”

CDFW Photos. Top Photo: Upper Butte Basin Wildlife Area Manager Tim Hermansen releases a wild turkey after banding as Fish and Wildlife Technician Derek Schiewek and Seasonal Aid John Davis look on.

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

Categories: General
  • June 11, 2018

Man holding large cardboard box in front of man holding turkey.
Tim Hermansen of CDFW carries a turkey holding box to CDFW’s Levi Sousa while John Davis clears the net.

Person holding turkey while another person holds turkey foot against wooden post.
Derek Schiewek of CDFW holds a turkey while CDFW’s Laura Cockrell measures the tarsus.

Recent efforts to determine the number of turkeys on the Upper Butte Wildlife Area have been a net success.

CDFW staff and volunteers from the National Wild Turkey Federation (NWTF) began annual turkey banding efforts in 2015 to gather information about turkey demographics and movements to facilitate better management of the population and assess future hunting opportunities. Approximately a dozen volunteers and staff have since worked on this effort two months each year, in the late winter through early spring.

Captured birds are fitted with a numbered band, and their age, gender and weight are determined before they are released. The number of times a turkey is recaptured through ongoing trapping activities, or when a hunter returns a band to CDFW, provides data about the density and the movements of the birds. Approximately 20 wild turkeys have been captured each of the past four years, using air cannons that propel nets. Last year was the sole exception, as torrential storms resulted in zero captures because portions of the property were flooded and could not be traversed with trapping equipment.

“That year was very frustrating, but part of being a wildlife biologist is going with the flow,” recalled CDFW Environmental Scientist Laura Cockrell, who is involved in coordinating and facilitating wildlife surveys on the wildlife area.

This year, walk-in traps were used for the first time to supplement the traditional use of air cannons, and the final tally was 38 turkeys banded, increasing the total number banded over the course of the project to 88. This baseline data will inform decisions on how many turkey hunters will be allowed access to the wildlife area each spring.

“Our volunteers and all our staff are what makes this project successful,” Cockrell said. “Everyone completes a safety training so we can make sure the birds are handled quickly and carefully, and then it is a lot of ‘hurry up and wait’ during the trapping operations. If we did not have a dedicated crew on this project, it would not be successful. The walk-in traps allow staff to set up trapping operations in the morning, check the site throughout the day, and process birds as they are captured.”

Also appreciative of the banding efforts were turkey hunters, who had an extra “spring” in their step this year at the Upper Butte Wildlife Area.

The 2018 spring turkey hunts recently ended after 64 hunters who hunted on Upper Butte Basin harvested 35 turkeys. During the previous three spring seasons combined since spring turkey hunts began on the wildlife area in 2015, 133 hunters participated and 47 turkeys were harvested.

All the result of field conversations between CDFW staff and fall turkey hunters.

“During the fall turkey seasons some years back, hunters at the check stations would frequently ask us when we were going to offer a spring season, which we had not done before,” Cockrell said.

At the wildlife area’s Howard Slough and Little Dry Creek units, the problem was not a lack of turkeys but rather a lack of funding to hire staff to advertise, prepare, regulate and operate the extra hunts – and a lack of scientific data to support an extra hunting season.

A collaborative effort between CDFW and the NWTF solved that problem.

In 2014, NWTF applied for and received a state grant from the Upland Game Bird Stamp Fund. The grant proposal, which was spearheaded by NWTF District Biologist Kevin Vella, obtained five years of funding to support a seasonal coordinator position.

“This spring we had almost 1,800 applications for 144 open spots,” said Cockrell. “Our hunters really appreciate the opportunities that the spring turkey hunts provide. We frequently hear after a hunt what an amazing time they had out in the field and how much they enjoyed their time on the wildlife area. One of our hunters this season was so excited because he was able to harvest a nice turkey at his very first hunt!”

All photos © National Wild Turkey Federation, all rights reserved. Top Photo: Tim Hermansen of CDFW holds a turkey while Laura Cockrell of CDFW measures its beard with calipers.

Categories: General
  • March 20, 2018

A young woman with a rectangular wire cage containing two trapped, brown doves
Two doves in a backyard wire trap

A woman's right hand holds a dove's right wing outstretched
A bander holds out a dove’s wing to see which feather has most recently molted, which will provide information about the age of the bird.

A brown and gray dove with a silver band on its leg is held outdoors in a woman's hand
A volunteer trapper prepares to release a banded female.

If you have an interest in migratory upland birds – as a hunter, a birdwatcher or just a citizen scientist – there’s a unique volunteer opportunity coming up that will allow you to work hands-on with wildlife, while helping the California Department of Fish and Wildlife collect critical research data that will become part of a national database.

Approved volunteers will be specifically trained over the next few months and permitted to capture mourning doves for a seven-week period, from July 1 through August 20, 2018. Banders attach a metal leg band to each bird, determine the bird’s age and sex , and record the data before releasing the bird. Banders can choose their own trapping sites, which in many cases are on their own property.

CDFW is particularly in need of volunteers in North Coast and Bishop areas, but as this is a statewide program, volunteers from other areas may be able to participate as well.

“It’s a unique opportunity for wildlife enthusiasts to get hands-on experience and play an important role in the management of California’s number one game bird,” explains Karen Fothergill, an environmental scientist and coordinator of CDFW’s Mourning Dove Banding Program.

Several levels of participation are possible, but successful completion of a four-hour training session is mandatory for all participants. Trained volunteers will band in their local areas, ending 10 days prior to the start of the hunting season for mourning doves.

The imprinted bands that are attached to birds’ legs are an important tool used by wildlife managers to help them evaluate mourning dove populations. Band recovery data is incorporated into the US Geological Survey Bird Banding Laboratory database and used by wildlife managers to monitor the status of mourning dove populations.

Together, the volunteer force will band approximately 4,000 mourning doves around the state. This number – which is necessary for accurate population modeling – has only been achieved with the use of volunteers.

Volunteer training opportunities will be held around the state, depending on how many potential volunteers show interest in participating, and where those individuals are located. Fothergill said that she expects to hold at least four training opportunities in the month of May. For scheduling purposes, potential volunteers are asked to contact Fothergill no later than April 13.

Volunteers are not compensated, but all supplies will be loaned at no charge.

Program participants must be over 18 and have good organizational skills and a commitment to wildlife preservation. The trapping and banding work is typically done in the morning and evening, but volunteers who can only work limited hours or on certain days can still be utilized and are welcome. For more detailed information about the program or to reserve a space at a training session, please contact Karen Fothergill at (916) 716-1461 or Karen.Fothergill@wildlife.ca.gov.

CDFW photos.
Top Photo: Mourning dove (Zenaida macroura)

Categories: General
  • September 21, 2017

CDFW Seasonal Aid Katie Schroyer determines the age of a dove by examining its wing

light brown mourning dove held humanely in someone's hand
A banded mourning dove at a CDFW trap site in northern California

a woman's hand spreads a mourning dove's wing above a notebook
Age and sex data are recorded before the bird is banded and released.

a wire mesh bitd trap, approximately ten-by-seven-by-seven feet, in what looks like a barnyard
A large kennel trap can catch more than 30 birds at a time.

As the second half of California’s split dove season kicks off, dove hunters may put more than birds in their bags. They may harvest a bird with a band on its right leg – thus getting an opportunity to contribute important data that will help guide future management efforts.

Since 2003, California has been an active partner in a nationwide assessment of mourning dove populations. California is one of 39 states that currently participate in dove banding. During the months of July and August, trained biologists and volunteers trap and band doves throughout the state. The banding of migratory birds requires a Master Banding Permit issued upon approval of a study application by the U.S. Geological Survey. All banders must pass an annual training to participate and are then issued a sub-permit.

Mourning doves are so widely distributed that banding operations can be – and are – located almost anywhere, from rural locations to urban backyards. Larger operations located on Wildlife Areas, ranches and open desert sites may employ the use of a large kennel trap capable of trapping 30 or more birds at a time, while smaller operations (“backyard banders”) use small Kniffin traps that catch just one or two birds at a time.

When a bird is banded, age and sex data are recorded. This information, along with capture location, date, bander name and corresponding band number, becomes part of a massive database managed by the USGS’s link opens in new tab or window Bird Banding Laboratory. The mourning dove banding data is available to any interested party, but is mainly used by the link opens in new tab or windowU.S. Fish and Wildlife Service (PDF), university scientists and state agency scientists to analyze and estimate annual survival, harvest rates, recruitment and abundance.

The resulting analysis is used by wildlife managers in setting annual hunting regulations. For instance, in 2015, the USFWS increased the take of mourning doves in the Western Management Unit (which includes the states of California, Oregon, Washington, Idaho, Nevada, Utah and Arizona) from a daily bag limit of 10 to 15. The California Fish and Game Commission followed suit, also increasing the possession limit from two to three times the daily bag limit, in order to accommodate hunters on multi-day hunting trips.

If you harvest or find (encounter) a banded bird, CDFW asks that you report the number directly to the Bird Banding Laboratory. This can be done online at link opens in new tab or windowwww.reportband.gov, or by calling (800)327-2263. When reporting an encounter you will be asked for the band number and basic information about where and how you obtained the band.

The person reporting is allowed to keep the band, and will receive a certificate with the details about where, when and by whom the bird was banded.

The USGS Bird Banding Lab is the keeper of banding data for both the US and Mexico. As of September 18, 2017 and since 1960, the BBL has received over 64 million banding records. Since the inception of the North American Bird Banding Program, the BBL has received over 4 million encounter records. On average, over the past decade, the BBL received 1.2 million banding and 87,000 encounter records per year.

For more information about mourning dove banding, including the 2017 Mourning Dove Harvest Strategy, visit the link opens in new tab or windowDoves and Pigeons page on the FWS website.

CDFW photos by Kloey Helms
Featured photo: CDFW Seasonal Aid Katie Schroyer determines the age of a dove by examining its wing.

Categories: General