Recent accomplishments of CDFW's scientific community
CDFW Seasonal Aid Katie Schroyer determines the age of a dove by examining its wing
A banded mourning dove at a CDFW trap site in northern California
Age and sex data are recorded before the bird is banded and released.
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 Bird Banding Laboratory. The mourning dove banding data is available to any interested party, but is mainly used by the U.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 www.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 Doves 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.
Beneath the waters off the California coast are vast forests that are home to an astounding variety of animals. Their sunlit canopies can soar 150 feet from the ocean’s floor. But instead of trees, these forests are made of kelp.
Worldwide, kelp is used in a host of everyday products like toothpaste, pudding, ice cream and even pharmaceuticals. Although kelp is valuable to humans, it is critical to sustaining life for many ocean-dwelling wildlife species ranging from microscopic plankton to sea otters, pelagic birds and predatory fishes. When a kelp forest is depleted, the entire underwater ecosystem can be thrown out of balance. This is why CDFW scientists are tracking and studying the amount of kelp growing in coastal waters.
In 1989, CDFW marine biologists began using aerial surveys to monitor the size of the kelp forests off of California’s coast. A second survey was conducted a decade later, and since 2002, CDFW has made an effort to conduct these surveys annually (although budget issues sometimes require skipping a year).
The surveys are conducted along the entire coastline and offshore of the Channel Islands. CDFW conducted the earliest surveys on its own, but now contracts out for this work. The contractor uses an aircraft with a specialized camera system that picks up the infrared image of the kelp. Those images become Geographic Information System (GIS) shapefiles that capture a snapshot of what the kelp canopy looks like on a given day. The images enable the viewer to see and compare the spatial area of a specific kelp forest over time.
A graph depicting CDFW’s historic aerial kelp survey data is located on the Kelp and Other Marine Algae webpage.
CDFW’s most recent (2016) kelp survey includes the following findings:
Rebecca Flores Miller, a marine environmental scientist with CDFW’s Marine Region office in Monterey, was the coordinator for the 2016 kelp survey.
“Kelp does fluctuate normally, anyway … there is a seasonality with it,” she explains. “However, during El Nino and warm water conditions as we’ve had in the recent past, the canopy doesn’t grow as well.”
Coastal development can also negatively affect the kelp canopy, as it sometimes leads to pollution, increased turbidity (which reduces the light needed for photosynthesis) and siltation (which can hinder growth or bury young kelp). An increase in urchin populations can also have a dramatic impact on kelp, and recently, a wasting disease decreased the numbers of sea stars (a predator of urchins) statewide.
“All of these things are connected within the ecosystem,” Flores Miller says.
Kelp survey data is available to anyone who is interested – members of the general public, other governmental agencies, universities and researchers.
The dataset has many uses, both within and outside of CDFW. It is used during the review process for commercial kelp bed lease requests. It has been a critical piece of the Marine Protected Area planning process. It has been used to help predict the abundance of many kelp forest-dependent species valued by humans, such as abalone. And it has helped scientists understand issues such as the recent abalone die-off in northern California.
CDFW Photos: giant kelp and bull kelp (by Rebecca Flores Miller), and image of kelp forest near Cambria taken during the 2016 aerial kelp survey.
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