Probably our most striking set of summertime visitors are members of the genus Icterus, the new world orioles. Orioles are part of the family Icteridae, a group that includes seemingly unrelated birds like grackles, blackbirds, bobolinks, cowbirds and meadowlarks. Though widely diverse, all icterids are notable for one or more uncommon characteristics including elaborate behavior, complex nest-building, unusual vocalization and gregariousness.
Of these traits, orioles are known for colorful, contrasting plumage, vocalization and unique nest construction. Of nine U.S. orioles, Arizona counts three of the five common species as summer nesters (Hooded, Bullock’s and Scott’s), the other two common birds (Baltimore and Orchard) and one of the four uncommon species (Streak-backed) as fairly-regularly reported rarities. Not surprisingly, Arizona ranks high in state-documented oriole species, one more reason birders find their way to our state.
The name ‘oriole’ is onomatopoeic, dating back to 1250, when the similarly-looking (but unrelated) old world Golden Oriole was named for his melodious song. Our male orioles have striking plumage of black, yellow, orange and white, and even the duller females (sorry, ladies) are beautifully colored in muted yellow, green and olive. Orioles are slender, with long tails and sharp bills. Although primarily insectivorous, orioles have a sweet tooth, so to speak, and will strip flowers to get to nectar, and they love fresh orange halves as well as grape jelly. They also are regulars at hummingbird feeders, capable of drinking sugar water from the narrowest of feeder holes. Orioles weave beautifully elaborate pendulous nests from plant fibers. Scott’s Orioles nest in relatively low yucca plants, using dead yucca leaf fiber, while the Hooded Oriole (SaddleBrooke’s most common oriole) prefers palm trees, stripping thin fibers from palm leaves and weaving them into the underside of other palm leaves. These precarious, hanging sack-like nests are designed to protect eggs and nestlings from climbing predators, and are the reason we should postpone palm tree pruning until Labor Day, when our orioles begin returning to their wintering grounds in Mexico. Our nesting orioles arrive in March or April, raise one or two broods typically, and then fly home to Mexico or Central America in September.
These broods sometimes include an intruder. Bronzed Cowbirds, a very different-looking Icterid family member, are parasitic with a particular affinity to Hooded Orioles. Cowbirds don’t bother building nests, they simply wait for a host bird to leave for lunch, then swing by the nest long enough to drop an egg of their own, which is incubated by the host bird along with her own eggs. The stranger typically is fed and fledged by the hosts, who have tolerated these intrusions for millennia.
On occasion, a rare oriole will miss the September bus out of town. This happened to us in the fall of 2010. A male Hooded Oriole showed up at our hummingbird feeders in mid-September, after our nesting birds had left the state. We watched this same bird hang out in our yard through October, November, December and the following severely cold January and February, even though his roosting spot in an oleander lost all its leaves and we were thawing frozen sugar water regularly. We called him Gray Head due to his darker than normal crown, and continued to be amazed at his stubborn refusal to head south. This was a time of escalating cartel violence in Mexico, so maybe he just thought he was safer in Arizona.
(This article originally appeared in the August, 2014 issue of the Saddlebag Notes newspaper, Tucson, Arizona.)