Seagulls, also known as gulls, are a widely distributed group of seabirds in the family Laridae. While the common perception of seagulls is that they are all white, some species do have brown plumage or brown color variations. Understanding which seagulls can be brown and why can help birdwatchers properly identify these coastal birds.
Why Are Some Seagulls Brown?
There are a few reasons why some seagull species or populations have brown plumage:
- Species characteristics – Some gull species, like the Slaty-backed Gull and Black-tailed Gull, have brown plumage for at least part of their lifecycle. This is an evolved species trait.
- Age – Young gulls often have brown speckled plumage that transitions to more solid white or grey as they mature. Immature Brown-hooded Gulls are mostly brown.
- Seasonal – During non-breeding seasons, some normally white gulls develop brown spotting on their heads and necks. This includes the Laughing Gull.
- Individual variation – Even within a typically white species, some individual gulls express more brown shading or barring on their feathers.
- Dirt/staining – The white feathers of some gull species can become dirty or stained brownish from mud, algae, or iron oxide in the water.
So in summary, brown coloration in gulls can relate to species traits, age, seasonal changes, individual variation, or staining. It is not abnormal to see brown gulls, as white is not the only plumage color within this family of birds.
What Species of Seagulls Can Be Brown?
There are several species of seagulls that regularly display some degree of brown plumage. The most common brown-colored gull species include:
- Slaty-backed Gull – This medium-sized gull has slate brown upper wings and back. It ranges around northern Pacific coastal areas.
- Black-tailed Gull – Found across northeast Asia, this species has variable brown mottling across its body and black tail feathers. Immature birds are mostly brown.
- Brown-hooded Gull – This South American species has a brown head and neck as an adult. Immature gulls are entirely brown.
- Black-headed Gull – In non-breeding seasons, this widespread gull develops a brown head and neck, contrasting with its white body.
- Franklin’s Gull – Some individuals of this small gull have darker brownish-grey plumage instead of the typical black head and white body.
- Lesser Black-backed Gull – A variant of this European/Asian gull has brown instead of black upper wings.
Other species like the Laughing Gull, Sabine’s Gull, and Mediterranean Gull can develop brown spotting or streaks during certain seasons or as immatures. And even normally white gulls like the Herring Gull sometimes display brown aberrations.
Identifying Brown Seagulls in North America
For birders in North America, there are a few brown-colored seagull species to keep an eye out for:
- Slaty-backed Gull – Look for this gull along the northern Pacific Coast, where it spends the non-breeding season. Its dark grey-brown back and wings are unique.
- Lesser Black-backed Gull – The European subspecies graellsii rarely occurs along the Northeast Coast. If seen, look for a brown (not black) back and yellow legs.
- Franklin’s Gull – Scan flocks of small gulls for individuals with brown-grey plumage, especially around the Great Plains and Midwest, where this species breeds.
- Laughing Gull – This coastal gull develops brown speckling on its head in winter but retains a black head and dark red beak.
- Brown-hooded Gull – A South American species, vagrants can occasionally reach the southern US coastline, displaying a chocolate brown hood.
Some immature common gulls like Herring Gulls and Great Black-backed Gulls also show mottled brown patterns before getting their familiar white and grey adult plumage. So be careful with identification if you spot any brown juveniles.
Best Locations to See Brown-Colored Seagulls
Since species distribution determines where brown seagulls occur, here are some top sites worldwide to potentially spot them:
- Coastal Alaska – Find brown-backed Slaty-backed Gulls and juveniles here.
- Pacific Northwest – Spot both Slaty-backed Gulls and intermittent brown-shaded individuals.
- Japan – Diverse gull fauna includes Slaty-backed Gulls, Black-tailed Gulls with brown spotting.
- Kamchatka Peninsula, Russia – Breeding grounds for Slaty-backed Gulls.
- UK Coastline – Regular influx of European brown-backed Lesser Black-backed Gulls.
- Chile/Southern Argentina – Home to the Brown-hooded Gull.
- American Great Plains – Scan flocks for brown-hued Franklin’s Gulls.
- Northeast US Coast – Rare brown subspecies of European gulls occasionally occur.
Seawatching at these locations during the right time of year can produce sightings of various brown-colored gulls, whether as regular residents or migrants. Even spotting individuals with abnormal brown plumage can add excitement for birding enthusiasts.
Rarity of Brown Seagulls
Species | Regular Brown Plumage? | Abundance Where Found |
---|---|---|
Slaty-backed Gull | Yes | Common |
Black-tailed Gull | Yes | Common |
Brown-hooded Gull | Yes | Uncommon |
Black-headed Gull | Seasonal only | Abundant |
Franklin’s Gull | Partial | Common |
Lesser Black-backed Gull | Subspecies only | Rare vagrant |
As this table shows, most brown-colored gull species are fairly common where they occur normally. However, the European lesser black-backed gull subspecies with brown backs is considered very rare in North America. Likewise, South American brown-hooded gulls only occasionally wander north of their normal range. So while some brown seagulls are abundant, others represent mega-rarities for birders to hope to spot.
Why Do Some Gulls Stay Brown?
There are evolutionary explanations for why some seagull species maintain brown plumage while most develop white or light grey feathers:
- Camouflage – Brown feathers help gulls like the Slaty-backed blend in along coastal rocks and cliffs in their range, providing concealment from predators and prey.
- Mate attraction – Darker pigmentation may help attract mates, as studies show female gulls favor males with more intense grey or brown colors.
- Diet – Pigments obtained from certain carotenoid-rich crustaceans and fish may help produce reddish-brown feathers in some populations.
- Genetic isolation – Birds separated from white-plumaged populations may evolve or retain brownish coloration.
- Dominant genetics – In the case of the brown-backed Lesser Black-backed Gull, brown seems to be a dominant gene variation from the black-backed form.
So from blending into the environment to attracting mates, there are viable reasons why retaining brown plumage could be selectively advantageous for some seagull populations and species. The specific ecological and genetic factors driving this divergence in coloration from the typical white gull are important for ornithologists to continue investigating.
Conclusion
Seagulls encompass a wide array of species across many environments, and not all conform to the archetypal white coloration many people imagine. Brown seagulls occur regularly in certain species and populations, while even typically white gulls may display seasonal or abnormal brown patterning. Understanding which species normally exhibit brown plumage, what causes brown coloration, and where to spot brown-hued gulls can enrich any birding experience at the world’s coastlines. So keep an eye out for these remarkable and under-appreciated brown seagulls!