On October 9th, 2005 I was enjoying the view at First Encounter Beach in Eastham, Massachusetts and watching a small flight of seabirds. A flock of gulls began to gather on the beach close to my car and I found myself more and more engrossed in the plumage variation of Ring-billed Gulls. This first photo shows two first-fall Ring-billed Gulls sleeping, with very different plumage – the one on the left still in full juvenal plumage, while the one on the right has replaced most of the body feathers with first-winter plumage.
This much is familiar to many experienced birders, but on this date I was struck by the fact that these two birds, in two different plumages, are more or less the same age. That is, they were both born in the summer of 2005, but by early October one has advanced into the next generation of feathers, while the other retains all of its juvenile feathers. The difference in appearance is striking, with variation in molt timing combined with variation in juvenal and first-winter plumage colors. Note also the difference in leg color, which seems to parallel variation in bill color.
I photographed about 15 immature Ring-billed Gulls that afternoon, and I have arranged the photos here according to plumage: from full juvenal plumage to the most advanced first-winter plumage. The bird on the left appears below in photo number 1, the bird on the right in number 10.
These were digiscoped with a Nikon Coolpix 4300 hand-held to the 30X eyepiece of a Swarovski AT80 HD telescope. The sky was overcast with some light rain, requiring long exposures and accounting for the blurring in some photos.
5 thoughts on “Variation in immature Ring-billed Gulls”
Excellent. Many thanks for a clear, step-by-step lesson in an area which I’ve always found daunting.
I have always had trouble identifying the early phases for immature ring billed gulls. Your photographs help immensely in making the identification much easier. Thanks for the info.. Gregory Watkevich
Thank you for the very helpful information.
I have always wondered about this topic, with waterfowl and other groups of birds and I think it hs something to do with actual birthdate of the juvie. For example, we can have breeding birds from May through July orAugust, so looking at two birds that may have been born up to 3 months apart will show up by the younger birds not having enough time to go through the process as fully as the older birds.
Just a thought!
It is February 15th, 2014. I just got finished getting a long, close look at a young gull that “should” be a summer-plumaged Ring Bill (I am in Plattsburgh, NY). Very dark tail; mid-tone dark brown flight feathers with pale tips; dark cheeks but lighter nape, neck and crown; slender bill…dark all over with warmer tones near the base; pinkish legs. Can’t figure out what else it could be. Saw it standing next to an adult Ring Bill and it appeared a smidge slight/smaller. Who knows? Any feedback would be greatly appreciated. Please reply to my email with “Gull” in the heading. Thanks!