The California Gull (Larus californicus) is a medium-sized gull that breeds primarily in western North America. Some quick facts about the California Gull:
- It is the state bird of Utah.
- It has a white head and body, gray wings, black wingtips, and yellow legs and feet.
- It measures 38–48 cm (15–19 in) in length with a wingspan of 97–105 cm (38–41 in).
- It typically lives 10–15 years.
In this article, we will explore the California Gull in more detail, looking at its physical description, habitat and range, diet and feeding, breeding and reproduction, behavior, conservation status, and cultural depictions. Read on to learn more about this iconic North American seabird!
Physical Description
As noted above, the California Gull is a medium-sized gull, similar in size to the familiar Herring Gull. Some key physical features include:
- Size: 38–48 cm (15–19 in) in length with a 97–105 cm (38–41 in) wingspan.
- Weight: 325–525 g (11.5–18.5 oz).
- Plumage: White head, body, and tail. Gray wings and back. Black wingtips with white spots. Yellow legs and feet.
- Bill: Medium-sized, yellow with a red spot near the tip of the lower mandible.
- Eyes: Brown.
- Sexes are similar.
- Juveniles have mottled brown plumage, taking 2-3 years to reach full adult plumage.
The California Gull has a stout body shape with long, pointed wings. In flight, the black wingtips contrast sharply with the gray back and white body. The legs extend just past the tail in flight. Compared to other gull species, the California Gull has a smaller, more tapered bill relative to its head size.
Size Comparison
Species | Length (cm) | Wingspan (cm) |
---|---|---|
California Gull | 38-48 | 97-105 |
Herring Gull | 55-65 | 125-155 |
Ring-billed Gull | 48-57 | 120-150 |
As this table shows, the California Gull is smaller than the abundant Herring and Ring-billed Gulls across most of its range. The size difference helps distinguish it in mixed flocks of gulls.
Habitat and Range
The California Gull nests in interior regions of western North America. Its breeding range centers on the Great Basin but extends into surrounding areas as well. Some details on its habitat and range:
- Breeding range extends from southern British Columbia through the western US to northern Mexico.
- Nests mainly around lakes and rivers in the Great Basin region.
- Winters along the Pacific Coast from southern Alaska to Mexico.
- Vagrant individuals may range further inland and east during winter.
- The world population is estimated at 110,000-120,000 birds.
During the breeding season, California Gulls nest in large colonies on islands in lakes and wetlands. They prefer areas with flat or gently sloping islands that provide protection from mainland predators. Some major nesting sites include the Great Salt Lake in Utah, Mono Lake in California, and Flathead Lake in Montana.
Outside of the breeding season, California Gulls are highly migratory. They winter primarily along the Pacific Coast, congregating in harbors, bays, lakes, and river mouths from southern Alaska to Mexico. Some birds may wander east into the interior of the continent during winter as well.
Breeding and Wintering Range
Season | Range |
---|---|
Breeding (April – July) | Interior lakes and wetlands of western North America from southern British Columbia through western United States to northern Mexico. |
Wintering (September – March) | Pacific Coast from southern Alaska to central Mexico, some individuals wander inland. |
This table summarizes the primary breeding and wintering ranges of the California Gull. The species migrates between these inland and coastal areas each year.
Diet and Feeding
California Gulls are opportunistic feeders that utilize a wide variety of food sources. Their diet can vary based on habitat and season. Some key elements of their feeding ecology include:
- They are generalists, not specialists.
- Diet includes insects, fish, crustaceans, worms, small vertebrates, eggs, grain, and scraps.
- Forage by surface plunging as well as digging in ground.
- Scavenge opportunistically at landfills and sewage outfalls.
- May drop hard-shelled prey items from height to break them open.
- Drink fresh water but have salt glands to eliminate excess salt.
California Gulls feed both in coastal marine environments and at inland lakes, rivers, and agricultural areas. At the coast, they consume fish, intertidal invertebrates like crabs and mollusks, marine worms, and plankton. Inland, their diet shifts to include more insects, small rodents, eggs, and plant material. They opportunistically scavenge any readily available food sources.
Common Foods
Habitat | Common Foods |
---|---|
Coastal | Small fish, crabs, mollusks, marine worms, plankton |
Inland lakes & rivers | Fish, aquatic invertebrates, insects, rodents, eggs |
Agricultural areas | Grains, insects, small mammals, eggs |
Landfills & sewage | Scraps, organic waste |
This table summarizes some of the common foods eaten by California Gulls in major habitat types. The species is flexible and opportunistic in its feeding habits.
Breeding and Reproduction
The breeding ecology and reproductive behavior of California Gulls includes:
- Nest in large colonies of up to 25,000 pairs.
- Nest on the ground on islands, protected from mainland predators.
- Breed from April-July depending on latitude.
- Females lay 1-3 eggs (usually 3). Eggs incubated for 21-28 days.
- Chicks hatched with downy silver-gray plumage.
- Both parents feed chicks through regurgitation.
- Chicks fledge around 4-5 weeks old.
- May live 10-15 years.
California Gulls build nests on the ground out of vegetation and debris. Nests are usually placed in small colonies together for protection. The female lays a clutch of 1-3 eggs, most commonly 3. Both parents incubate the eggs for 21-28 days before hatching.
The chicks hatch with downy silver-gray plumage and are able to leave the nest within a few days. The parents feed the chicks through regurgitation. The chicks fledge at around 4-5 weeks old and reach sexual maturity at 2-3 years old. Lifespan is typically 10-15 years.
Breeding Timeline
Breeding Stage | Timeframe |
---|---|
Egg laying | April – May |
Incubation | 21 – 28 days |
Chicks in nest | 4 – 5 weeks |
Fledge | June – July |
This table shows the typical breeding timeline for California Gulls, spanning from egg-laying in April-May through fledging of chicks in June-July. The exact timing varies across their range.
Behavior
The behavior of California Gulls includes:
- Strong fliers, sometimes soaring high similar to hawks.
- Bathe by dipping onto water surface while swimming.
- Roost communally at night, sometimes far from feeding sites.
- Aggressive in nest defense and competing for food.
- Omnivorous and opportunistic in feeding.
- Make a variety of vocalizations like laughing calls and alarm calls.
- Pick up marine gastropod shells and drop them to break them open.
California Gulls are very social birds that nest, feed, migrate, and roost in groups. They are aggressive defenders of nesting territories, using vocalizations and aerial attacks against intruders. Their strong flying skills allow them to migrate long distances annually.
They spend much of their time loafing near water or opportunistically scavenging. California Gulls utilize a diverse array of feeding techniques, reflecting their generalized diet. They are intelligent birds that have adapted well to man-made food sources like landfills.
Conservation Status
The California Gull has a large population and extensive range across western North America. Its conservation status includes:
- Population estimated at 110,000 – 120,000 individuals.
- Listed as Least Concern on the IUCN Red List.
- Populations increased in the 20th century with creation of reservoirs.
- Protected under the Migratory Bird Treaty Act.
- May face threats from water diversions, lead poisoning, and climate change.
- Manages well around human activity and modified habitats.
Overall, the California Gull has a healthy global population even with some localized declines. New reservoirs and man-made food sources have likely helped buoy populations in the last century. They remain common and widespread across western North America.
Ongoing protection of key breeding colonies and wetland habitats will be important for the continued success of California Gulls, given threats like habitat loss. Limiting lead pollution will also help reduce mortality events. But in general, the California Gull remains a resilient and adaptable species.
Cultural Depictions
The California Gull hasSignificance in human culture due to:
- Being designated the official state bird of Utah in 1955.
- Association with the early Mormon settlers in Utah.
- Flocks of gulls helping control a cricket plague in Utah in 1848.
- Appearing on the flag of Salt Lake City, Utah.
- Sometimes called the Mormon Gull.
- Use as the mascot for Pomona College athletic teams.
In Utah, the California Gull has special cultural importance linked to the Mormon pioneers. It is said that flocks of gulls helped save the first crops of settlers in Utah’s Salt Lake Valley by devouring swarms of crop-damaging crickets in 1848. This story led to the designation of the California Gull as the state symbol of Utah.
This history has led to the species being prominently featured on seals, flags, and in artistic and athletic representations of Utah. The California Gull remains a state emblem representing Utah’s natural heritage.
Conclusion
In summary, the California Gull is a medium-sized gull speciesbreeding in western North America and wintering along the Pacific Coast. Identifying features include its gray wings, black wingtips, and yellow bill and legs. It lives near waterbodies where it feeds opportunistically on aquatic and terrestrial prey.
California Gulls breed in colonies on inland lakes and migrate coastally in winter. They are aggressive defenders of nesting territories. Their resilience has allowed populations to thrive near human activity. The species carries cultural significance in Utah where it is the official state bird. Protection of remaining wetland habitats will help ensure the continued success of this adaptable North American gull.