Friday, April 22, 2011

The dark side of meadowlarks: an annotated bibliography

Western Meadowlark, Merced National Wildlife Refuge
A ruthless killer. (photo by Chuq Von Rospach)

You might not know it, but meadowlarks are carrion-eating scavengers, egg-eating nest predators, and even cold-blooded killers! I didn't know either, until I stumbled upon a series of articles detailing the full scope of their gruesome taste for blood. I'll get right to the bibliography... 

Terres, J. 1956. Eastern meadowlark eating a traffic-killed bird. Auk 73:289-290.

The first hint of these dark tendencies was revealed in a 1956 article by John Terres of the National Audubon Society. In it he relates a chilling scene of cannibalism that must have made an impression, as it occurred 17 years before the article was published. It was early July 1939, in upstate New York. Along the edge of a well-traveled road, a dead meadowlark is systematically pulled to bits by a live member of its own species. Terres, perhaps too professional to express his presumed horror in anthropomorphic terms, coolly excuses the behavior as simply making nutritional sense. As he put it, "I see no reason why almost any wild songbird might not be inclined to eat meat if it had the opportunity."

Hubbard, J. P. and C. L. Hubbard. 1969. Meadowlarks feeding on road-kills. Wilson Bull. 81:107-108.

Further light was shed on this scavenging (and cannibalistic) tendency one snowy day in December 1967. John and Carrie Hubbard were driving along a lonely desert highway in New Mexico in a blizzard, when they witnessed a curiously macabre scene. They began to notice dead birds along the roadside. Lots of them. Horned larks, mourning doves, lark buntings and meadowlarks, all apparently killed by cars as they foraged in the only snow-free areas around: tire ruts. The Hubbards made their way along this gruesome route, where "bodies littered the highway and roadside," stopping frequently to collect specimens (typical biologists, apparently). Before long they began to get suspicious. At each carcass (including those of meadowlarks) one or more live meadowlarks would often flush. Later examination of meadowlark stomach contents confirmed their suspicions: feathers and bird skin pieces were main components. 

Tyler, J. D. and L. L. Choate. 1990. Opportunistic scavenging by meadowlarks in southwestern Oklahoma. Proc. Okla. Acad. Sci. 70:41-42.

Twenty years later, a similar but even more grizzly scene was witnessed on Interstate 44 in Oklahoma after a massive ice storm. Dead birds (and mammals too) were everywhere, killed in the same manner: struck by cars while scrounging for seeds on ice-free roads. The article by Jack Tyler and Larry Choate of Cameron University reads like an account of a plague or epic natural disaster. The body count included nearly 500 meadowlarks (eastern and western),  over 900 mourning doves, "great numbers" of bobwhites, and mammals including house cats, hispid cotton rats, and cottontails. Throughout this scene of carnage, a mixed flock of eastern and western meadowlarks roamed and feasted on the flesh of mammal and bird alike. There also seemed to be a vicious circle in effect, in which meadowlarks were struck by cars while feasting on road-killed meadowlarks which were struck while feasting on...etc.

Schrick, M. P. 1979. Tree Sparrows killed and eaten by meadowlarks. Bull. Oklahoma Ornithol. Soc. 12:33-34.

Now it's getting serious. I was willing to accept carrion-feeding in meadowlarks, but predation...that was too much to believe. Again the scene is rural Oklahoma during a mid-winter blizzard. Michael Schrick of the Corp of Engineers had been shooting starlings at a bird feeder with a pellet gun (?!) and was shocked when the meadowlarks below the feeder began "pecking at and eating" the corpses. And this despite the piles of seeds he had scattered for them. Imagine his surprise two days later when he witnessed the following. I quote:

  • Park Ranger Wes Masonhall and I saw a meadowlark suddenly walk toward and grab with both feet a Tree Sparrow, a maneuver that obliged the meadowlark to fall to its side while striking its victim
    with its beak. The commotion did not seem to frighten the Tree Sparrows, but it did attract the other meadowlarks, several of which started to peck the captured sparrow. Rivalry developed: one meadowlark, more aggressive than the others, jabbed savagely at the sparrow's captor, forcing
    that bird to release its prey. The aggressor strode off with the dead sparrow in its beak. When it stopped to feed, however, the other meadowlarks put it to flight. Eventually, still carrying the sparrow in its beak, it disappeared in the distance.
    Almost immediately, the vanquished meadowlark caught another sparrow; another free-for-all developed; and the sparrow was killed and eaten. The living sparrows, obviously ravenous, and possibly weakened by starvation, did not seem to realize that the meadowlarks would be predatory.

Wow, that is real drama! Rivalry, vanquishing, victims, starvation, free-for-alls, striding, aggression. It has it all. This turned out to be the first of several accounts indicating that meadowlarks, when pushed to the edge, will kill.

Waters, L. S. 1990. Meadowlarks prey on Pine Siskins and American Goldfinches. Bull. Okla. Ornithol. Soc. 23:7-8.

Bell, P. M. 1990. Eastern Meadowlark predation on American Goldfinches. Bull. Okla. Ornithol. Soc. 23:20-22.

An Oklahoma bird feeder, mid-winter, recent snowfall. Starting to see a pattern. 

Two separate articles by Patrick Bell and Luann Waters published in 1990 not only added significantly to the body count attributable to meadowlarks, but also shed light on their ghoulish methods. For example: "Part of the roof of the finch's skull was gone, as was half the brain." And "another goldfinch had a massive opening in its cranium..." And "bird was killed by pecks to the back of the head and then left intact while the meadowlark returned to the feeder and ate sunflower seeds...Later, the meadowlark came back, ate the brain first..." Aaaaahhh!

Creighton, P. D. and D. K. Porter. 1974. Nest predation and interference by Western Meadowlarks. Auk 91:177-178.

Schaeff, C. and J. Picman. 1988. Destruction of eggs by Western Meadowlarks. Condor 90:935-937.

Picman, J. 1992. Egg destruction by Eastern Meadowlarks. Wilson Bull. 104:520-525.

Say it ain't so. Not only do they kill adults, but they also kill babies. Specifically they have a taste for eggs of horned larks and lark buntings, and even Coturnix quail and clay eggs placed in artificial nests. Presumably, eggs of all ground nesting species would suit their pallets. And nestlings are also fair game, apparently, as Creighton and Porter found a lark bunting chick with "deep puncture wounds in the back and neck" after the nest was "inspected" by a meadowlark.

So, after all is said and done, can we excuse these anthropomorphically distasteful behaviors of eastern and western meadowlarks - namely cannibalism, infanticide, and murder? I say: maybe so. At least on the basis that they seem to occur mainly in extremely harsh circumstances (think "Donner Party"), and primarily in Oklahoma.

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