Friday, December 28, 2012

Mew Gulls, Part 2

This is a follow-up to last night's post.  In that entry, I included images of adult Mew Gulls.  Here are a few photos showing immature Mew Gulls.

Gull plumages can be confusing.  It takes gulls between 2-4 years to attain adult plumage (the timing depends on the species).  During the first few years, their appearance changes dramatically.  They usually start out mottled brown/gray and gradually become grayer above and whiter below.  The color patterns on their wings and tails also change, as do their bill and leg colors.

So instead of learning what *a* Mew Gull looks like, you need to learn at least 3 or 4 different plumages (e.g., juvenile, first-year, second-year, adult).

Here's a picture showing an adult Mew Gull in the foreground and a second-year Mew Gull in the background.  Can you see differences between these two individuals?


In the second-year bird (in the background above):

- the head and neck are more heavily mottled with gray
- the bill and legs are more gray/green than yellow (see legs in photo below)
- the black primary feathers (wing tips) lack the large white spots and instead show very narrow pale edges
- the tertial feathers show black markings [Tertial feathers are actually elongated inner secondary feathers located where the trailing edge of the wing meets the body.  In these images, the tertials have broad white tips and are visible between the gray back/upper wing and the black wing tips.]
- the tail has black markings (not that visible in these birds, but adults have all white tails)

Here's another view of the second-year Mew Gull.  Look for all of the characteristics listed above:



If you'd like to quiz yourself, here are two more images (below).  Can you tell which is the adult and which is the second-year bird?



Answer: The first photo shows a second-year Mew Gull, the second image is an adult Mew Gull.

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