Salmon Carcasses Donated
Q: When adult (returning) salmon are processed for eggs at hatcheries, what happens with the carcasses?
A: CDFW has an agreement to donate Chinook salmon carcasses that are fit for human consumption to the California Emergency Foodlink. That agency then works with food banks throughout California to distribute the salmon that comes from five northern California hatcheries. Nearly 70,000 pounds of fish from the recent fall-run Chinook salmon migration were donated.
Here’s why salmon are available for those donations. Returning adult fish that swim hatchery gates and up fish ladders are anesthetized before they are spawned. Anesthesia methods used at CDFW hatcheries include carbon dioxide and electro-anesthesia, which keep these fish safe for consumption. CDFW is careful not to waste the carcasses and has been working with California Emergency Foodlink for more than 20 years.
Solo Flight vs Flocks
Q: Why do some species of birds fly in groups of hundreds – or thousands – while some fly or live seemingly single?
A: 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.
Bears in California
Q: I believe that I may have stumbled upon a grizzly bear in California in June of last year. Is that possible? I live in Siskiyou County, near the Oregon state line.
A: In California, the native grizzly bear (Ursus arctos, also known as the brown bear) went extinct around 100 years ago, leaving California with just the one bruin, the black bear that inhabits the entire state. It can be easy to mistake a black bear for a grizzly bear though, due to the tremendous variation in black bear colors and sizes we have in California. Many black bears in California possess a brown coat just like their larger and more aggressive relatives. In addition to brown, California also has many animals that are black, dark brown, cinnamon and even some that are blonde. The size of black bears can also vary widely. While most black bear adults are going to be somewhere between 150 to 300 pounds and easy to distinguish from the much larger grizzly adult, there are many more than 300 pounds and some individuals weighing over a whopping 600 pounds, which is heavier than a lot of grizzlies. Grizzly bears are found today in Alaska, Wyoming, Montana, Idaho, Washington and western Canada. Ear shape, shoulder hump, facial profile and claw length are reliable features used by biologists to distinguish between the two types of bear in areas of species overlap.
California’s black bear population has increased over the years. In the early ‘80s the statewide population was estimated to be between 10,000 and 15,000 bears. The current population is estimated to be between 30,000 and 40,000.