THREE LOOKS OF
THE YUCATAN JAY

At a certain spot in the scrub near my casita you can nearly always see a flock of eight or so Yucatan Jays, CISSILOPHA YUCATANICUS. You're hiking along, a bird gives a warning call, and into higher branches flush several mostly blue and black birds chattering and scolding CHA-CHA-CHA and rattling CHAHAH-URR-RR just as you might expect noisy, nosey jays of any species to behave. Of course, that's three of them above.

Yucatan Jays have been common and easy to see in most of my homes across the Yucatán. Back at Komchén I wrote, "At dawn, right outside my porch, usually there are a couple of horses grazing, just waiting for me to feed them my banana peelings. There's a white horse and a dark brown one, and the brown one very often has six to twelve Yucatan Jays riding him. Sometimes a jay descends the horse's tail looking for whatever might be suspended in the long hairs. Sometimes a couple of jays sit for a long time just watching the horse's tail-hole. ... Most of the jays riding the brown horse appear to be enjoying the trip. They perch in a line along the horse's spine, looking around, squawking, preening and billing their neighbors."

Despite their commonness and familiar ways, they're endemic -- in the whole world found only in the Yucatán Peninsula and adjacent Belize, northern Guatemala and a little into the northern Isthmus of Tehuantepec. The flock near my casita is composed of birds exhibiting three distinct colorations, as shown in the picture at the top.

The black-billed bird at the top, left exhibits the typical adult appearance. The yellow-billed bird at the right is an immature bird, the main differences being that his bill is yellow and the ring around his pupil -- his "orbital ring" -- is yellowish, instead of black as with the adult. The inset at the lower left shows another immature Yucatan Jay, but younger than the first one, with yellow beak and white head and lower parts. The yellow beaks of young birds become black by their third winter. Howell in A Guide to The Birds of Mexico and Northern Central America reports the mostly white plumage as seen only from July through September, so I was lucky to capture it.

In sorting out the above color differences I needed to be a bit more discriminating in the use of certain terms than I have been, the terms being "immature," "juvenile" and "juvenal."

Howell defines "immature" as a general term for non- adult birds; "juvenile" birds are those in their first feathered, or "juvenal," plumage, and; "juvenal" is the term used for the first feathered, or non-downy, plumage of a young bird. Therefore, both of the non- adult birds in the picture are immatures," but only the one with a lot of white is a "juvenile."

Yucatan Jays are "cooperative breeders," a term applied to species in which several individuals, usually closely related, help with nest building, incubation, feeding young, etc. "Immature" Yucatan Jays help their parents take care of their even younger siblings, the "juveniles" in their "juvenal" plumage.

It shouldn't be surprising to find any species of jay exhibiting a more-complex-than-normal social structure. Jays belong to the same bird family as crows and magpies, and most birders agree that those are among the most highly evolved and intelligent of all birds.