Larks and Icterids

The Icterid family is a large one, made up of blackbirds, cowbirds, grackles, meadowlarks, bobolinks, and orioles.  (I added a true lark here—the Horned Lark—even though it’s not an Icterid.  So sue me.)  Icterids get their name from the Greek for “jaundice” or “yellow,” since many of the members of this family have markings of yellow.  Here are write-ups written for rehab volunteers about Horned Lark (an Icterid interloper), Common Grackle, Bullock’s Oriole, and Western Meadowlark.

Horned Lark—the “true” lark of America

How fitting that, one week after writing about the non-lark Western Meadowlark, we now turn to the only true lark species native to North America—the Horned Lark.  A small, ground-dwelling songbird, its “horns” (actually feather tufts on the top of its head) can be raised or lowered.   Although its body is brown streaked with dusky brown or black, it can be easily identified by its black face mask and broad black “necklace.”  Here’s a photo of an adult male.  Living primarily in open, barren country, they prefer areas with a lot of bare ground and with vegetation only a few centimeters high.  Horned Larks crouch in depressions to escape inclement weather or detection by predators.  Horned Larks breed in a variety of barren areas, from desert to alpine habitats.  In fact, this wide range of breeding preferences is perfectly reflected in their scientific name:  Eremophila (from Greek for “desert-loving”) alpestris (from Latin for “belonging to the mountains”).  Interestingly, Horned Larks are one of only four species in Colorado that breed above treeline.  (For those keeping score, the other three are Brown-capped Rosy-Finch, American Pipit, and Rock Wren.)

Horned Larks live nearly everywhere in the U.S., although they only move to the southeast in the winter.  They can be found in Colorado all year, although they migrate from higher to lower altitudes in the winter and form large nomadic flocks that can be seen skimming over bare, wind- and snow-swept fields in search of seeds.

The pattern inside the mouth of a nestling Horned Lark makes it relatively easy to identify:  1 black spot at the tip of the upper and lower mandibles (jaws), 1 at the tip of the tongue, and 2 toward the back of the mouth.  You can see the spots on the mandibles in the nestlings in this photo.  Although adult larks eat primarily seeds, a vast majority of the foods they bring to their nestlings are insects; grasshoppers make up the bulk along with beetle larvae and earthworms.  As with meadowlarks and other ground-nesting birds, the young leave the nest early—about 10 days after hatching, when they can walk but before they can fly well.  About 4 weeks after fledging, they can fly with the best of ‘em.  Although young larks begin to pick up food soon after leaving the nest, adults continue to provide them with food for two to three weeks.  The percentage of insects consumed plummets from about 100% at fledging to just above 10% once they are independent—probably because seeds are easier for the youngsters to find (and, no doubt, to catch!) than are insects.

Larks are famous for their flight songs, delivered high in the air during a floating, fluttering display flight.  This singing in flight presumably arose as a way to defend a territory in open habitat with no elevated perches.  Indeed, their musical, lilting, tinkling songs ring out unhindered—a lovely contrast to their barren surroundings.

It’s a warbler!  It’s a meadowlark!  No, it’s a Bullock’s Oriole!

If you’ve been in one of the baby bird rooms recently, you might have noticed a group that started out as “mystery babies.”  It took a while for them to let us know what they were, but they’re young Bullock’s Orioles.  Their scientific name (genus and species) is Icterus bullocksii.  Icterus is from the Greek word for “jaundice” or “yellow;” bullocksii is from William Bullock, who helped to identify this species in 1827.  Here’s a photo of an adult male—you can see that the “yellow” name is very appropriate.  Needless to say, if these kids had looked like this, we’d have had no problem figuring out their identities.  Orioles are part of the larger Icterid family, along with blackbirds, grackles, cowbirds, and meadowlarks.  So initial guesses that they might have been meadowlarks put them in the right family!

Bullock’s Orioles are in Colorado mostly between May and August, wintering in central Mexico and Central America.  They nest in deciduous trees, such as cottonwoods and oaks, by rivers, streams, and lakes.  They also can be found in urban parks—for instance, for the past several years, a pair has raised a family in a large tree overlooking one of the most popular lakes at the dog park at Chatfield State Park!  They eat mostly insects (butterflies, larval insects such as caterpillars, grasshoppers), fruit (blackberries, raspberries, cherries, and cut oranges at bird feeders), and nectar (either from flowers or from special feeders that look like HUGE hummingbird feeders, such as the feeder shown in the photo link above).  Oriole nests are among the most interesting bird nests.  Made primarily by the female, she weaves a pendulous, hanging nest out of hair (most often, horsehair), fibers, grass, twine, ribbon—I even saw one constructed primarily of fishing line!  She then lines the inside with fluffy cottonwood or willow seeds and feathers.  Babies leave the nest about 2 weeks after hatching, although they tend to hang around their parents for several days after that, while they learn about the world beyond.  So this summer, if you find yourself around water with tall deciduous trees, listen for a lively song of rich whistles and rattles.  You might also hear the classic oriole “chatter,” which the nestlings are making endlessly these days in the baby bird room.  That means the orioles are out and about!

Common Grackle—Colorado’s harbinger of spring

The Common Grackle is indeed a common bird in Colorado during breeding season.  Two thirds of Colorado’s Common Grackles frequent habitats associated with humans—rural habitats, croplands, or urban sites.  The scientific name is one of the most curious ones I’ve run into.  Quiscalus quiscula seems to mean “quail quail” in Latin—a rather odd choice for a member of the Icterid family (which includes Red-winged Blackbirds, Western Meadowlarks, and the cowbirds, among others).  Try as I might, I haven’t been able to find any definitive explanation for why someone chose this name.  Some things just remain a mystery.  The common name—grackle—derives from a European word meaning “croaker or garrulous.”  If you’ve ever heard what passes as a song for a Common Grackle—a harsh, unmusical squawk reminiscent of a rusty gate—you can understand this name choice a bit better.

A rather large songbird between 10 and 12 inches long, the male Common Grackle looks all black from a distance or in low light.  But bright light paints a different picture-the head is an iridescent, glossy purplish-blue or blue-green.  This beautiful iridescence arises from a complicated array of minute reflectors in the feathers, sometimes twisted so they work like the crystals of a tiny chandelier, absorbing and reflecting a range of light wavelengths.  Females are a bit smaller and duller than the males and have shorter tails; all adults have bright yellow-white eyes.  Fledglings are brown and have brown eyes until the end of their first winter, when their eyes too turn light.

Grackles are opportunistic foragers, taking advantage of any food source they can find.  On average, their diets are made up of about 25-30% animal matter (insects, minnows, mice) and 70-75% plant matter (fruit, grain, seeds).  The young typically depart the nest 12-15 days after hatching; the adults continue to feed them for several more weeks.  Some people don’t like grackles very much.  They can take over at bird feeders and they have even been known to eat bird eggs as well as  nestlings and adults.  But they are also one of the few species that will eat Japanese Beetles and House Sparrows—2 invasive species that have wreaked havoc on some native habitats.

Common Grackles have moved into the West from the East only in the past 50 years, aided greatly by the clearing of forests for agriculture and the planting of shelterbelts.  They can be found in Colorado until late October, returning in late March.  So, while many people think of the robin as the harbinger of spring, that’s not quite right in Colorado.  We can see robins here all year long.  But when the first Common Grackle appears at Colorado feeders in March, Spring can’t be far behind.

Western Meadowlark—the “lark” of the meadow

A chunky bird with a brown-streaked back, the Western Meadowlark is easily identified by its white tail edgings (seen well when flying away from you); a bright yellow throat, breast, and belly; and a V-shaped black “necklace.”  What is difficult is separating a Western Meadowlark from an Eastern Meadowlark.  They look pretty much the same, but their songs are definitely distinct.  The Eastern Meadowlark has a clear whistled “spring of THE year;” a Western Meadowlark, a jumble of loud, sweet whistles that is both indescribable and unmistakable.  This confusion between the two species is even reflected in its scientific name:  Sturnella neglecta.  Sturnella—”little starling”—comes from the Latin word for “starling” (“sturnus”) plus the diminutive “ella,”  even though a meadowlark is considerably larger than a starling (and generally speaking, a lot less annoying).  Neglecta was chosen because the Western Meadowlark was not separated from the Eastern Meadowlark until about 100 years after its first description.

A meadowlark feeds almost entirely on the ground—either at the surface or by probing beneath the soil by jabbing its closed bill into ground or beneath an object and then spreading its beak apart to find insects lurking under there.  Its diet consists mostly of grains, weed seeds, and insects (favorites include beetles, weevils, grasshoppers, and crickets).

Meadowlarks grow up quickly.  Nestlings leave the nests quite young, as soon as 10-12 days after hatching and typically before they can fly.  Their legs are strong but their flight feathers are not yet fully developed. As a result, they can run quickly for short distances, but they have to protect themselves from predators and other dangers primarily by hiding in dense vegetation, well camouflaged by their cryptic coloration. The young depend on their parents for food for up two weeks after fledging.

An errant Eastern Meadowlark wanders from the east into Colorado on occasion.  (One was documented as far west as Salida several summers ago.)  But by far, our most common meadowlark is the Western Meadowlark.  This photo shows a male Western Meadowlark in one of his most common summer activities—singing from atop a high perch in his territory.    You can hear a snippet of this glorious song here. (Scroll down and click on “listen to songs of this species.”)  And while it is indeed a gifted songster, the Western Meadowlark is not really a lark at all.  Instead, it is closely related to blackbirds and grackles (the Icterid family).  But when you heard that loud, lovely, liquid song wafting across a grassy field, you can understand why early settlers considered it the lark of the meadow.

© 2009 Tina Mitchell