Date: 4/3/26 12:39 pm From: Abram Fleishman <abfleishman...> Subject: Re: [MBBIRDS] Royal Tern San Lorenzo River Mouth April 1
There were two terns on Main Beach mid-morning today. Both looked similar
size and build. But maybe one was 5-10% larger. But that apparent size
difference may have been posture related.
Extent of white on forehead and black on nape was similar. Black on nape
extended to the eye in a narrow band. Both had stout bills with the
gonydeal angle 1/3 from the tip. Both birds had uniform bill color that did
not transition to a noticeably lighter color at the tip. They both had
clean white breasts And dark primaries. Neither had the long shaggy crests
I associate with Elegant terms but these were young birds so maybe not
fully mulleted yet. the bill did taper more than I expect for a Royal Tern
but only slightly. The size was hard to judge against the CAGU and WEGU
nearby. But was bigger than I expect for ELTE and smaller than I expect for
ROYT but I have not studied them extensively when I do not have both
species side by side.
Both birds are in the first winter plumage indicated by the dark centers to
the tercials. it must be noted that orange billed terns often continue to
grow their bill into their second summer so the shortness of the bill might
be age related.
Theresa two birds did not want to roost together and even though they
flushed several times they always landed in different parts of the gull
flock.
So looking at the pictures I took we either had two Royals or two Elegants
iNat IDed 10 of my 13 pictures as Royal, 1 as Elegant and 2 to the genus.
Merlin suggested Royal for several pictures even when cropping out the
head, or only doing the bill or the head with out the bill. 8 on my
pictures were of one bird and 5 were from another.
