Overdue Credit to a Frequent Flyer

North American folklore has touted the American Robin as the harbinger of spring.  Me—not so much.  For me, that honor goes to the Mourning Dove and its soft song drifting through the air beginning early in the new year. A Mourning Dove is a medium-sized, streamlined bird with an almost ridiculously small head; a long, pointed tail; and a plump, grayish brown or taupe body—one author called it “a teardrop with a tail or a pear on a stick.”  Black spots on the wings and behind the eye accent these otherwise rather drab colors.  Males and females look alike, although sometimes a discerning eye can detect a rosy blush on the male’s breast (emphasis on “sometimes”).  Since they often start singing in the pre-dawn darkness, some people mistake their songs for the calls of the nocturnal owls.  The whistle from its wings as it takes off provides another auditory clue that a Mourning Dove is near.

Doves have a number of interesting physical features.  For instance, they can drink with their heads down, using their beaks like a straw.  (Most other birds have to take a sip of water and throw their heads back, so the water can trickle down their throats.)  Primarily a seed-eater (a granivore), a dove can store lots of seeds in its crop (an enlarged part of the esophagus) then fly to another spot to digest them.  Unlike many other birds, a dove doesn’t have a uropygial gland (also called a preen gland), which contains oil used in preening to help waterproof its feathers.  Instead, it has powder down feathers, which are extremely fine feathers that disintegrate into a dust-like substance.  Through preening, the bird coats its feathers with this dust to provide some waterproofing.  If you’ve ever seen a window strike by a dove, you may have noted a “ghost bird” on the glass—a tracing of the bird left on the glass by powder down.  If you and the bird are both lucky, that’s the only remnant of the strike you’ll find.

The Mourning Dove’s scientific name is Zenaida macroura.  Zenaida was the first name of the wife of the French botanist Charles Bonaparte, who lived and worked in the early 1800s.  The species name refers to its long tail, from Greek—makros (“long”) and ouros (“tail”).  Its common name arises from its rather mournful-sounding (at least to some) song, while “dove” derives from the Anglo-Saxon dufen (“to dive”) for its irregular flight pattern (a derivation that seems a bit of a stretch to me).

Mourning Doves build pitifully meager nests, usually consisting of just a handful of twigs laid haphazardly.  The female nearly always lays two eggs, for which both parents share incubation duties for 14 days.  Mourning Dove babies (called squabs) grow very quickly, increasing their weight 14-fold in 15 days.  Initially, parents feed the kids crop milk—a mixture rich in protein and fat that is secreted by the adult’s crop lining.  As the nestlings grow, the parents switch to regurgitating seeds.  The nestlings fledge about 15 days after hatching and remain with the parents another two weeks, fed primarily by dad while mom starts another clutch.  Fledgling Mourning Doves look very much like their parents, except that their feathers have a scaly appearance:  Wispy, narrow white edges outline the tips of their feathers but wear off shortly after the young leave the nest.

Tied with the House Finch for San Diego County’s most widespread bird, Mourning Doves occur throughout most of the county year-round.  They are also the most widespread and abundant game bird in North America and, correspondingly, the most hunted species.  Yet population numbers of this species remain stable.  One key to the Mourning Dove’s continuing success is that, in spite of laying only two eggs per clutch, it has a short nesting cycle (about four weeks) and a long breeding season (February to September and sometimes beyond).  Mourning Doves can produce as many as five or six broods a year while many other species struggle to raise just one.  To fledge that many broods, Mourning Doves start early.  As a result, this dove’s song begins filling the air again this month, heralding the onset of yet another songbird breeding season.