Puerto Vallarta, Mexico - As if Vallarta's birdlife wasn't fascinating enough, every so often a real doozy shows up. This time, one individual of the otherwise locally common Yellow-winged Cacique (Cassiculus melanicterus) has a yellow head and crest (both normally black), and has created quite a stir at the Vallarta Botanical Garden's feeders, which are stocked at 1:00 pm daily.
This freak of nature has bewildered more than a few birders; each with their own hypothesis: Is it a hybrid? An aberrant albino? Does it exhibit what's known as Xanthochromism (replacement of normal color by yellow pigment)? All of these hypothesis and more have been expressed. Nobody seemed to know.
I spend quite a bit of time photographing birds with aberrant plumage characteristics, so I've done quite a bit of research over the years on the subject, and discovered that many so called Xanthrochroistic birds are actually what is known as Schizochroic!
Gross (1965), in his paper on North American birds, writes "...[in] non-melanic schizochroic individuals, the absence of melanin in their plumage leaves caratenoid pigments, which might be yellow or red, phenotypically."
This applies to members of the American Blackbird family (Icteridae), especially, & caciques are members of that family. That's what can be observed right now at the Vallarta Botanical Garden. Those interested in observing this amazing bird and other incredible Mexican bird species are encouraged to contact the author/photographer, Greg R. Homel, at BirdingInPuertoVallarta.com or birdingadventures(at)mac.com.
Pending a more thorough examination of available literature, this may very well be the first-ever documentation of this spectacular schizochroic anomaly in the near-endemic Yellow-winged Cacique.
Visit the internationally famous Vallarta Botanical Garden located just 30 minutes south of Old Town at Km. 24 on Highway 200 and easily accessible by public transportation and taxi. This 64 acre wildlife preserve and botanical garden have something fun for everyone. Over 200 species of birds have been observed on the Garden's grounds. Don't forget to bring your swimsuit for a refreshing dip in the jungle river. See plantings of vanilla, chocolate, and hundreds of other botanical delights! Authentic Mexican Cuisine is served in the Hacienda de Oro Restaurant from 10 am to 5 pm. The Garden is open daily from 9 am to 6 pm (closed Mondays from April 1 to December 1). Garden admission is just $200 pesos. For more information, call (322) 223-6182 or visit vbgardens.org.