Recent discussion on the Arizona/New Mexico Rare Bird Alert about sightings of a Yellow-bellied Sapsucker, reminded me of the flurry of e-mails created from my posting about a Yellow-bellied Sapsucker at the Cedro Group Camp, November 2009. Was it really a Yellow-bellied Sapsucker, or was it really an immature Red-naped Sapsucker?
According to an article published in the November/December 2006 issue of Birding, Variation in Red-naped and Yellow-bellied Sapsuckers (Mlodinow, Barry and Cox), “Interest among birders has been heightened by these species’ tendency to wander.” They go on to state that major field guides and several articles are “quick to caution that few if any of these marks are actually diagnostic,” and go on to point out the most significant identification challenges occur with hybrids, first cycle birds and atypical sapsuckers “which occur with some frequency.” Nearly every fall or winter, Yellow-bellied Sapsuckers are reported in central New Mexico.
One person commented that the throat of the sapsucker I had posted in my story was not all red – that the tiny chin was white and that the red throat encroaches upon the black border.A review by several people of the photos taken by another birder that showed several different angles resulted in the following comment from one individual. “The back pattern looks like a classic yellow-bellied – much more extensive white barring than is normally present on a red-naped. He went on to speculate that the bird might have been a hybrid, since sapsuckers that migrate through the Sandia and Manzano Mountains or winter here probably originate from the Rocky Mountain area of Canada where hybridization does occur.
Mlodinow, et. Al wrote in their conclusion that “all potential vagrant sapsuckers, need to be assessed by using the full suite of field marks, realizing that there is substantial overlap in almost every character…the ‘aberrant’ mark may be a sign of distant genetic introgression or even the expression of the phenotype of a common ancestor.”
Should our group have taken the leap to conclude that it was a Yellow-bellied, or taken the route of the most common species? There are probably differing viewpoints. All a person in the field can do is to consult as many guides as possible and compare as many characteristics as possible before attempting an ID – which is how we arrived at our conclusion.