July-Aug-2017-Lark-Buntings
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Hopping through the grass, the little sparrow aimlessly searched for seeds. Every so often he would suddenly fly to the top of the highest shrub, grass or flower stalk and burst into song. Only recently he had arrived on his Pawnee National Grasslands breeding grounds from his winter home on the Cabeza Prieta National Wildlife Refuge in southern Arizona. He was distracted because it was the beginning of the breeding season. His call warned other males that he owned this piece of grassland real estate and he intended to make it his breeding territory. Trespassers beware. Lark bunting male 6 Colorado Outdoors He was, however, quite different from How the lark bunting got its scientific and of Fringilla bicolor. Later it was discovered other grassland sparrows. Instead of the common names is convoluted. In 1834 John that Carl Linnaeus had already used Frin- characteristic shades of drab brown, he was Kirkwood Townsend and Thomas Nuttall gilla bicolor to describe the black-faced nattily dressed in sharply contrasting black traveled across the continent to collect spec- grassquit, a close relative of Darwin’s finches. and white, the only North American spar- imens and describe wildlife for the Academy So, in 1885, Norwegian born ornitholo- row so brightly colored. That isn’t the only of Natural Sciences of Drexel University in gist Leonhard Stejneger changed the scien- way he differed from other sparrows. His Philadelphia. When they reached the pan- tific name to Calamospiza melancorys to common name, lark bunting, misrepre- handle of Nebraska, Townsend collected clear things up. But the name muddied the sents his true family relationships. He is several specimens of a bird he called the waters even more. The generic name Cala- neither lark nor bunting. “prairie finch.” He gave it the scientific name mospiza derives from two Greek words: DO’S STAT RA E B LO IR O D C THE BUNTING Arti cle & Photos by Song plays an important role in the male lark bunting’s courtship, although the specifics are still unknown. It may be that females are able to tell which males will make the best mates by the quality of their songs. Lark bunting male July/August 2017 7 Kalamos meaning reed and spiza meaning male’s territory, he will fly rapidly toward until the final decision is made. Shortly finch which would lead you to believe that the other male to intercept him. He per- after the lot has been selected, the pair the lark bunting was a finch that inhabited forms and sings similar to the primary commences to build the house. marsh lands. His species name melanoco- song display, but more aggressively. This While the female scratches out the de- rys also derives from two words: Melas second display, directed only at males, is pression, the male pokes around gathering which is Greek for black and corys, which called the aggressive flight song, the lark leaves, twigs, hairs and other materials for is Latin for lark, leading you to believe he bunting equivalent of “dropping the construction of the actual nest. The female is a black lark; again untrue. His common gauntlet.” After females initiate egg laying, does most of the weaving, and when she is name is lark bunting, which only confuses males substantially decrease the frequency finished she will have constructed a tightly the situation further. His rich, melodious of both flight displays. Assuming lark bun- woven bowl about 4 inches in diameter song reminds one of a lark, while bunting tings are like other brightly colored song- and one and one half inches deep. It will is the common name given to several spe- birds, the pattern, intensity and hue of the take her nearly three days to complete and cies of Old World sparrows. Here in North male coupled with the vigor of his flight America, most buntings belong to the car- and song provide the female with cues to Lark bunting female dinal family. So what is this bird: finch, his fitness and the quality of his territory. lark, bunting, cardinal or sparrow? Not all males are successful in attracting About a decade ago, scientists from San a mate. In areas where breeding behavior Francisco State University set out to an- has been studied, breeding males outnum- swer that question by comparing the mito- ber breeding females to the extent that chondrial DNA of members of the North nearly half of breeding males wind up American sparrows. They confirmed the without mates. The situation is compli- lark bunting was a sparrow. It lay close to cated further because some paired males the trunk of the family tree indicating it breed with females other than their mates. was one of the earlier sparrow species to Nearly half of all nests contain at least one evolve. Its closest relatives were the lark hatchling that was sired by an outsider sparrow, another grassland sparrow, and who is frequently from a neighboring ter- the black-throated sparrow, a native of the ritory. southwestern desert-shrub communities. Variation in the quality of territories is In late February and early March, as yet another complicating factor. Suitable lengthening days begin to warm the breeding habitat tends to be patchily dis- southern landscapes where lark buntings tributed and varies with climatic condi- spend their winter, they initiate a leisurely tions during the breeding season. Wetter migration northward, arriving in Colo- years result in more breeding habitat and rado in mid-May. Flocks of a few to more vice versa. During dry years, paucity of than 100 males precede females. Almost suitable breeding territories might limit immediately males begin to disperse and the success of males in attracting mates. establish breeding territories, sparking the High-quality breeding areas are those renewal of their annual rites of spring. that provide choice nesting sites because An ideal nest site includes a room with a First one male, then another and an- selecting a nest site is deadly serious busi- view to detect predators. It should face other launches into the air flying up to 30 ness. An ideal nest site includes a room downwind from prevailing storms and feet before spreading his wings and para- with a view so predators can be detected toward the rising sun and be well chuting back to earth. All the while the and evasive tactics taken before the nest is drained. Most importantly, it should be male is gliding, he calls melodiously. This discovered. It should accommodate the well-shaded by vegetation that will not spectacular display in its entirety is called excavation of a cup-shaped depression deteriorate through the nesting season. the primary song flight. Its foremost pur- roughly 4 inches in diameter and 3 inches pose is to display the male’s vigor and deep. It should face downwind from pre- splendor so he can attract a mate. Song vailing storms and toward the rising sun. also plays an important role in the male It should be well drained. Most impor- lark bunting’s courtship, although the spe- tantly, it should be well-shaded by vegeta- cifics are still unknown. It may be that fe- tion that will not deteriorate through the males are able to tell which males will nesting season. make the best mates by the quality of their Like newlyweds shopping for a house, a songs. pair of buntings explores several possibili- Later, after the females have chosen ties before settling on a place for their nest. mates, the displays change. The primary The female pokes around the bases of flight song is directed predominately at likely shrubs, forbs and tall grasses, occa- females, the lark bunting equivalent of sionally scratching the surface. When she “strutting your stuff.” Once a pair is mated, leaves a site, the male inspects it and then but before females start laying eggs, males follows after her. Eventually the choices direct their flight displays toward other narrow down to three or four and another, males. If an outsider trespasses onto a more thorough, inspection takes place 8 Colorado Outdoors two days later she will lay her first egg. At are the thirteen-lined ground squirrels be- ize. Lark bunting nests seem to suffer only a rate of one egg per day, it will take her cause they are so numerous and because moderate rates of parasitism. Studies here five days to lay her clutch of sky-blue eggs. they forage extensively throughout lark in Colorado suggest that under normal Incubation won’t start until the last egg is bunting nesting habitat. circumstances only 15-20 percent of the laid. The eggs will hatch 12 days later, with But male buntings often aren’t the only nests are parasitized, most with a single the male and female bunting taking turns ones to leave a bit of themselves in their cowbird egg. And, although the Colorado on the eggs. One in four of the nestlings neighbor’s nest. About one nest in five will breeding bird surveys suggest a slight de- will be the offspring of a neighboring male contain eggs of a brown-headed cowbird. cline in lark bunting populations over the bunting. Half of the nests will be destroyed While the female bunting was building the past four decades, the decline is attributed by predators before they hatch and half of nest, a female cowbird carefully watched to habitat loss or degradation and adverse the nestlings will survive until they are the process, waiting patiently until the weather rather than cowbird parasitism. able to fly. The most serious nest predators mother bunting began to lay her eggs. Red veiny dock, white evening prim- Eggs are usually laid in the morning, after rose and blue locoweed paint a patriotic Brown-headed cowbirds parasitize the which the female bunting leaves the nest mosaic over a green grass backdrop.