Ring-billed Gull

Our most visible gull species provides endless opportunities to study how gulls visibly mature through molt. They also happen to be an exceptionally variable species in their first and second years. If you can wrap your head around these beasites, the sky is the limit. 

First Cycle

June

It's not uncommon to see juvenile Ring-billed Gulls leaving breeding colonies before their tail and primaries are not fully grown. Their bills are also still growing, appearing slim and small for their first few months. 

July

Juvenile, first cycle and second cycle Ring-billed Gulls are remarkably variable upon close inspection. 

August

Their darker scaly juvenile mantle feathers start getting replaced with gray "first winter" feathers by August. The bill also starts becoming more clearly pink at the base. 

September

Many birds have obtained the more familiar look of a young Ring-billed Gull - with a black-tipped pink bill and pale gray back - by September. 

October

Some later molting Ring-billed Gulls can still be found into October and early November (see below) presumably arriving from breeding grounds north of the Great Lakes. 

November

December

January

February

March

By late month, Ring-billed Gulls are showing signs of their spring molt with fresh gray feathers appearing on the mantle & wing coverts as well as cleaner white feathering on the body and head. 

April

Spring hormones sometimes also lead to brighter colours on their bills, gape and legs. 

May

Second Cycle

The change from first to second cycle depends on the timing of the start of the inner primary molt. May/June is used here as an inaccurate / arbitrary cutoff. 

June

Molt is rapid. Birds may be hardly recognizable due to the changes happening from early May to late June. 

July

"Second cycle" Ring-billed Gulls take on a very adult-like plumage; however, note the extra black markings in the wing coverts and primaries (including small primary mirrors and smaller apical spots). Some may also have black tail markings, darker eyes or atypical colouration on the bill and legs (e.g., greenish, bluish, pinkish, etc.).

August

September

October

November

December

January

February

March

April

Once again, spring hormone levels start to change bare part colouration, usually with legs and bills becoming more yellow. 

May

By May, some first cycle Ring-billed Gulls can replace enough body feathers that they may cause some confusion with second cycle individuals when standing - while some adult Ring-billed Gulls will have the white apical spots on the tips of their primaries worn off. 

Third Cycle / Adult

Through their molt into third cycle plumage, Ring-billed Gulls obtain an "adult" plumage for the rest of their lives. While true "third cycle" Ring-billed Gulls would be detectable through the early summer (e.g., June), they soon lose their distinctiveness. As such, only full adults are presented below. 

June

July

August

Flight feather molt in late summer can make for some oddly ratty or short winged appearances.  

September

October

November

December

January

February

Warm weather in late winter can bring large numbers of white-headed individuals in "breeding plumage" - sometimes contrasting with individuals that wintered locally and retain their head streaking.

March

By March, nearly all adult Ring-billed Gulls have obtained their white-headed "breeding" plumage. Bare part colouration becomes particularly bright. Rarely, some individuals may have orangish bills or legs. 

April

May