Elegant Tern

I was at Bolsa Chica Ecological Reserve on Saturday, just across the Pacific Coast Highway from Huntington Beach. There was a cacophony of bird noise and hundreds of terns streaking about through the air. 

As I got above a small rise I saw several small strips of low-lying land in the salt water bay covered in terns, jockeying about, flying in and flying out and occasionally all leaving at once in a huge flock circling about and then coming back. 

Several times I saw them dive bomb into the water with a big splash, going for fish. 

I was excited to learn I had seen my first elegant terns and even more excited to learn that I was seeing one of only five breeding colonies of this bird. The largest breeding colony, at Isla Rasa, in the Gulf of California, Mexico, has 90 to 97% of the entire breeding population. There is a much smaller breeding population at Western Salt Company in San Diego Bay; since 1987 a breeding colony at Bolsa Chica Ecological Reserve; since 1992 a 275 pair breeding colony at Isa Montague in the Colorado River Delta of the Gulf of California; and since 1998 up to 3,000 pairs in Los Angeles Harbor. There is a total population of about 90,000 pairs. I recall in May 2021 hearing about a drone crash-landing near the colony in Bolsa Chica which scared off 2,500 elegant terns, leading to a catastrophic loss of that years potential new additions. It migrates south to Peru, Ecuador and Chile for the northern winter. Some also travel north to northern California, Oregon and even Washington in late summer and fall, before heading southward for the winter. 

Elegant tern range from Birds of the World. Orange dots are breeding and blue is migration. 

It has a long, slender, down-curved light red to reddish/orange bill (with the tip often yellow or light gray and the base is often red); pale gray upperparts and white underparts (sometimes with pink flush); a black cap and long shaggy crest, the longest of all terns; a deeply forked tail; and black legs, sometimes with yellow or orange splotches, and even entirely red. 

I got a very helpful comment on this post which indicated that these shaggy headed terns in my photos below are actually royal terns and not elegant terns. That elegants often nest near royals. I assumed that with the long shaggy crest might come long sticky-up "hair," but photos in All About Birds confirms that they are royals. Thank you so much to the anonymous poster. 

I really love the shaggy black crest. I believe they are displaying, a courtship ritual. 

It appears that the flying terns are elegants and those on the ground are royals.