If a seagull has black eyes, it likely means one of a few things:
It is an immature seagull
Seagull chicks hatch with dark grey to black eyes. Their eye color gradually changes to yellow as they mature over 2-3 years. So a black-eyed seagull is likely a juvenile that has not reached full adult plumage.
It is a different gull species
The most common seagulls with yellow eyes are Herring Gulls and Ring-billed Gulls. However, there are some other gull species that naturally have dark eyes:
- Great Black-backed Gull
- Slaty-backed Gull
- Kelp Gull
- Lesser Black-backed Gull
So if the gull has all black eyes and is fully mature, it may be one of these less common species.
It has an eye condition or injury
In rare cases, a seagull’s eye may appear black due to an injury or condition like:
- Cataracts – Clouding of the lenses
- Blown pupil – Rupture of the iris that makes the pupil enlarge
- Oil contamination – Oil coating the eye from exposure
- Blunt trauma – Damage turning the eye black
However, these conditions are not common in seagulls. A healthy seagull’s eye would not typically turn black.
It is adapting to an urban environment
There is some evidence that seagulls living in urban environments are evolving darker feathers and eyes. This may be an adaptation to avoid predation. Lighter eyes stand out against dark rooftops and pavement.
One study in 2021 found herring gulls in Bristol, England had darker eyes than their rural counterparts, suggesting urban evolution.
It could be leucistic
Leucism is a condition where birds have reduced pigmentation. While less common than albinism, leucistic birds have darker eyes compared to red or pink eyes in albinos.
So if a gull has very pale plumage but black eyes, it may be leucistic rather than an albino.
Conclusion
In summary, the most likely reasons a seagull would have black eyes include:
- Being a juvenile
- Belonging to a species with naturally dark eyes
- Adapting to an urban environment
- Having leucism
While it could potentially signal an eye condition, this would be relatively rare in most seagull populations. So when you spot a black-eyed gull, it’s usually nothing to worry about!
The seagull family (Laridae) is extensive and widespread, with over fifty species distributed across most coastlines and some inland habitats around the world. Differences in eye color can be a useful way to identify specific members of this family.
Seagull species with typically dark eyes as adults include:
Species | Eye Color |
---|---|
Great Black-backed Gull | Dark brown |
Kelp Gull | Dark brown with red orbital ring |
Slaty-backed Gull | Dark brown |
Lesser Black-backed Gull | Dark brown |
Meanwhile, most gulls in the Larus genus have yellow eyes, including:
Species | Eye Color |
---|---|
Herring Gull | Pale yellow |
Ring-billed Gull | Pale yellow with orange orbital ring |
California Gull | Yellow |
Glaucous Gull | Pale yellow |
The eye color difference is apparent right after hatching. Herring Gull chicks have brown-black eyes while Great Black-backed Gull chicks have jet black eyes from birth. Eye color gradually transitions to the adult shade as the birds mature.
In addition to innate species differences, individual gulls may have dark eyes due to:
- Immaturity – They are still developing their adult plumage
- Injury or disease – Such as cataracts, blows to the head, or oil contamination
- Melanism – Increased melanin pigment, often in urban populations
- Leucism – Reduced melanin pigment throughout plumage
So when observing gulls, look at eye color in combination with other features to identify the species. Then you can also note any individuals that stand out with unusually dark eyes compared to others of the same type.
Frequently Asked Questions
Why do seagulls have different colored eyes?
Seagulls have different colored eyes primarily due to species differences. Some gull species naturally have dark brown or black eyes, while others have yellow eyes. The eye color is genetically determined and helps distinguish between similar-looking gull types.
At what age do seagulls eyes turn yellow?
Seagulls that have yellow eyes as adults start out with black or brown eyes as chicks. The eye color gradually changes to pale yellow over 2-3 years as the birds mature. Full adult plumage and eye color is attained by ages 4-5 in most gulls.
Why are seagulls eyes turning black in cities?
There is some evidence that seagulls in urban areas are evolving darker eyes over successive generations. Having black eyes may help camouflage them against dark rooftops, avoiding predation. This is an example of microevolution adapting gull coloration to different environments.
Can seagulls have eye problems that make their eyes black?
Yes, certain eye injuries or diseases can make a seagull’s eye appear black. Examples include cataracts, oil contamination, blows to the head, and parasitic infection. However, these conditions are relatively uncommon in healthy gull populations.
Is a seagull with black eyes albino?
No, an albino seagull would have pink or reddish eyes due to lack of melanin. Black eyes indicate melanin pigment is still present, just reduced compared to normal yellow eyes. The condition leucism can cause black eyes along with paler plumage.
Conclusion
In summary, seagulls display variation in eye color between different species. Some types naturally have dark brown or black eyes. Juvenile gulls also start out with dark eyes that change to paler shades as they reach maturity over 2-3 years. Rare individuals may have black eyes due to injury, disease, or genetic conditions affecting pigmentation. But in general, eye color in seagulls provides a handy visual clue to identify species and life stage when observing these ubiquitous coastal birds.