January 24, 2024

Question: Why do some species of birds fly in groups of hundreds – or thousands – while some fly or live seemingly single?

Answer: There can be many benefits to living or traveling in groups. Flocks of birds may gather for longer-distance migration or even shorter-distance local movements. Groups of birds also may assemble during the breeding season with many individual birds nesting in a colony. The main advantages of being an individual bird in a flock or nesting colony have to do with safety and finding food resources. Birds within a flock can help alert others to potential predators and other threats. The more eyes there are, the better it is to detect predators. Being in a group can also decrease the chance of any one individual within the flock or colony being taken by a predator. The scientific name for this is called the dilution effect, the more bodies there are the lower the chances of being the individual taken by the predator. Birds in a flock also can improve food-finding and wayfinding for other members within the group. For example, snow geese are a migratory bird that breed in the arctic and overwinter in parts of California and elsewhere in the U.S. and Mexico. The juvenile snow geese hatched that season in the arctic breeding colony have never migrated south. It’s common for juveniles to migrate in family groups with their parents and siblings within the larger flock, which helps juveniles find their way and locate food resources. For bird species that feed on relatively abundant plants or insects, such as waterfowl or small songbirds, it can be beneficial to be in the company of others both for safety and locating food resources.

The primary disadvantage to group living is competition for food and other resources like mates or territory. When a bird must expend a lot of energy to obtain its next meal, such as catching live prey, it can be beneficial to forage alone. For example, many raptors are mostly solitary outside of the breeding season. An individual raptor is in direct competition with its neighbor for limited food resources. Catching live prey, such as small mammals and birds, can require high energy expenditure to obtain. Given the high cost of catching the prey, the raptor benefits most from consuming the prey itself without having to share.

January 11, 2024

Question: Is it true that frogs hibernate during colder times of the year?

Answer: Black bears aren’t the only wildlife species in California that hibernate in winter months. There are 27 species of native toads and frogs in the state and many hibernate, whether in water or on land. Mountain yellow-legged frogs are a good example. To escape frigid weather, the frogs take shelter in underwater rock crevices and submerged vegetation located in deep pools, which are less likely to freeze over.

Elevation plays a big role in what time of year this happens, with frogs at higher elevations having longer hibernation periods than those at lower elevations. Once the frogs find a perfect location, they can remain there throughout winter. During hibernation, the frogs heart rate and metabolism slow enough that the animals don’t require food.

A common misconception is that hibernating frogs bury themselves in mud at the bottom of a pond or stream. But unlike a hibernating turtle, frogs would suffocate without access to oxygen-rich water.

Terrestrial frogs normally hibernate on land, burrowing deep into the soil and safely below the frost line.

January 11, 2024

Question: Is it likely that Tulare Lake will continue to exist year after year, or could it drain off and disappear again?

Answer: When it’s full of water, Tulare Lake in Kings County is practically the size of Lake Tahoe. The major rivers which feed Tulare Lake are dammed and diverted for agricultural and municipal water uses so the lake only fills during exceptional rain years. Tulare Lake made a dramatic reappearance last year after a heavy rainy season, and the lake is likely to remain present in 2024 with rainfall predictions once again being above average.

CDFW is deeply involved in the monitoring of Tulare Lake because of the health implications for the state’s bird populations. As a main landing spot within the Pacific Flyway, millions of waterfowl, shorebirds and other bird species are expected to spend time there. It’s because the water is stagnant and too warm in summer months that avian botulism occurs.

The disease is caused by a toxin-producing bacteria that appears naturally in bodies of water like Tulare Lake. During bacterial growth, the botulinum toxin becomes concentrated in the bodies of invertebrates, such as fly larvae, which are then eaten by waterfowl and other birds, infecting them.

The last large avian botulism outbreak in Tulare Lake happened in 1983 when approximately 30,000 birds, mostly waterfowl, died. The numbers were far more encouraging last year, with fewer than 5,000 deaths. CDFW worked with the US Fish and Wildlife Service, UC Davis School of Veterinary Medicine’s, Oiled Wildlife Care Network and California Waterfowl to quickly collect dead birds to slow the spread of the bacteria and treated more than 1,200 birds releasing nearly 900 healthy birds back into the wild.

December 28, 2023

Question: What’s an example of how CDFW engages diverse groups in the state of California?

Answer: In 2022, CDFW created a Deputy Director position overseeing Justice, Equity, Diversity and Inclusion (JEDI) to help the department better understand the cultural needs of different population groups living in California. It’s also a CDFW goal to have our workforce better reflect California’s diversity. Meaningful engagement with communities is an essential part of building trust and relationships with diverse groups across California.

One example was a CDFW outreach event led in Spanish and English at the popular 1,700-acre Elkhorn Slough National Estuarine Research Reserve in Monterey County, which is owned and managed by CDFW and operated in partnership with the National Oceanic and Atmospheric Administration and the Elkhorn Slough Foundation. Celebrating the 2023 Latino Heritage Month in September, the JEDI office with support from Latino Outdoors held an open house at the reserve, featuring a day of family friendly events including a nature walk and bird viewing. Many who attended the event were from the surrounding communities like Pajaro, Castroville and Watsonville, which have large percentages of Spanish-speaking households.

In 2024, CDFW will be celebrating Black History Month in February, Women’s History Month in April, Asian American and Pacific Islander Heritage Month in May, Pride Month in June, Latino Heritage Month in September, Filipino Heritage Month and Native American Heritage Month in October.

December 20, 2023

The California Department of Fish and Wildlife (CDFW) will open the commercial Dungeness crab fishery from the Oregon state line to the Sonoma/Mendocino county line (Fishing Zones 1 and 2) under a Fleet Advisory beginning Jan. 5, 2024 at 12:01 a.m. with a 64-hour pre-soak to begin on Jan. 2, 2024 at 8:01 a.m. The commercial fishery will remain delayed from the Sonoma/Mendocino county line to the U.S./Mexico border (Fishing Zones 3, 4, 5 and 6) until at least the next risk assessment due to elevated numbers of humpback whales resulting in increased entanglement risk.

CDFW is also continuing the temporary recreational crab trap restriction from the Sonoma/Mendocino county line to Lopez Point, Monterey County, (Fishing Zones 3 and 4) due to the presence of humpback whales and the potential for entanglement with crab traps. The recreational trap restriction will be in effect until at least the next risk assessment. The use of recreational crab traps in Fishing Zones 1, 2 and 5 will be allowed. A Fleet Advisory remains in effect for the recreational fishery for all Fishing Zones (1-6). CDFW reminds recreational crabbers that take of Dungeness crab by other methods, including hoop nets and crab snares, is allowed during a temporary trap restriction. CDFW also encourages recreational crabbers to implement best practices, as described in the Best Practices Guide.

CDFW anticipates the next risk assessment will take place on or around Jan. 11, 2024, at which time Director Charlton H. Bonham will re-evaluate available data to inform the potential for a commercial fishery opener in Fishing Zones 3-6 and modification of the recreational trap restriction. For more information related to the risk assessment process, please visit CDFW’s Whale Safe Fisheries page. For more information on the Dungeness crab fishery, please visit www.wildlife.ca.gov/crab.

December 7, 2023

The California Department of Fish and Wildlife (CDFW) is continuing the temporary recreational crab trap restriction from the Sonoma/Mendocino county line to Lopez Point, Monterey County, (Fishing Zones 3 and 4) due to the presence of humpback whales and the potential for entanglement of humpback whales and leatherback sea turtles with trap gear. The recreational trap restriction will be in effect until at least the next risk assessment. The temporary trap restriction currently in effect in Fishing Zone 1 (Cape Mendocino to the Oregon state line) will be lifted at 8 a.m. on Saturday, Dec. 16, 2023, at which time the use of recreational crab traps in Fishing Zones 1, 2, 5 and 6 will be allowed. A Fleet Advisory remains in effect for the recreational fishery for all Fishing Zones (1-6). CDFW reminds recreational crabbers that take of Dungeness crab by other methods, including hoop nets and crab snares, is allowed during a temporary trap restriction. CDFW also encourages recreational crabbers to implement best practices, as described in the Best Practices Guide.

The commercial Dungeness crab fishery in all Fishing Zones (1-6) will remain delayed due to high numbers of humpback whales and a recent confirmed entanglement of a leatherback sea turtle in commercial Dungeness crab fishing gear lost in a previous season.

CDFW anticipates the next risk assessment will take place on or around Dec. 21, 2023, at which time Director Charlton H. Bonham will re-evaluate available data to inform the potential for a commercial fishery opener and modification of the recreational trap restriction. For more information related to the risk assessment process, please visit CDFW’s Whale Safe Fisheries page. For more information on the Dungeness crab fishery, please visit www.wildlife.ca.gov/crab.

November 30, 2023

Question: What’s the purpose of putting tags in salmon that are released from hatcheries?

Answer: CDFW implants millions of fish each year with tiny metal tags engraved with codes indicating when and from which hatchery a fish was released into the wild. When the salmon return to their release location a few years later, CDFW scientists collect that important information.

The fish are about five months old, living and growing in a hatchery raceway, when they’re brought in for tagging. The adipose fin on the fish (between the dorsal fin and tail fin) is also clipped, which is a visual indicator of which fish have the metal tags, and which ones do not.
The tagging happens at several CDFW hatcheries each year. At the Nimbus Fish Hatchery, east of Sacramento, about a million fish are tagged annually. The fish are about three inches in length when tagged. At roughly the six-month mark, the fish are released.

CDFW Interpretive Services Supervisor Laura Drath explained the importance of tagging salmon.
“The information on the Coded Wire Tag allows us to assess the success of our practices,” said Drath. “We're seeing not only how many hatchery-bred fish are returning, but also which of our release sites are most successful.”

The information retrieved from the tags helps CDFW monitor and adjust management techniques if needed. If a release site is not yielding a good return that site may not be used in the future. CDFW’s goal is to keep the fish population sustainable by using these tools and strategies.