Border battles

red-bellied woodpecker on fence (Photo: Brian Peterson, Creative Commons license)

Robert Frost said, “Good fences make good neighbors” but embattled red-bellied woodpeckers must find other ways to protect their territories. (Photo: Brian Peterson, Creative Commons license)

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Last Sunday morning I unexpectedly found myself sitting ringside for a brief but furious brawl. Two male red-bellied woodpeckers (Melanerpes carolinus) were having a boundary dispute that started with an argument over some shrubbery then escalated into a full-on aerial assault. Colliding mid-air, they grasped one another by the feet and were so intent on punching, pecking, and plucking, the adversaries flew thoughtlessly over the nearby road directly in front of my car. Luckily, I was making my way slowly along the otherwise quiet suburban street, so I was able to stop and watch.

With my windshield serving as an impromptu HDTV, the smackdown aired for all of 45 thrilling seconds and then, as if in response to a referee’s break command… it was all over.  Each fighter retreated, shouting insults over his shoulder as he returned to his corner.

male and female RBW by Jason Paluck, Creative Commons licenseRed-bellied woodpeckers (let’s just shorten that to RBWs, shall we?) are a medium-sized bird—just over 9” (24 cm) from chisel beak to stiff tail tips with a 13-16” (33-42 cm) wingspan. Like many North American woodpeckers, they wear a black-and-white houndstooth jacket, but their bright red Mohawk (males sport a full forehead-to-neck cap while females wear an abbreviated version) sets them apart. It’s also the reason these birds are so often misidentified as the similar-sized red-headed woodpecker (Melanerpes erythrocephalus), although once the difference is pointed out the mistake is rarely repeated. RBWs take their name from a subtle scarlet stain on their buffy belly.

red-headed vs. red-bellied woodpeckers by Laura Gooch and Jason Paluck, respectively (Creative Commons license)Year-round residents in U.S. wetlands, river bottoms, woods, and wooded suburbs from the Midwest east to the Atlantic coast, RBWs are omnivorous, consuming all manner of  insects, nuts, seeds, sap, and fruit. They store surplus food in various nooks and crannies and, since they don’t migrate, their larders come in handy during winter. This species employs gender-specific foraging strategies—males search for sustenance primarily along bole while females spend the bulk of their time on the boughs.

Biologists don’t often venture out on a limb to officially identify any non-human behavior as play, but I’ve notice the profession has loosened up a bit on this issue over the past decade or so, thankfully. One example of this trend was a description of RBW behavior I read recently. This species will periodically engage in swift, nimble, and unpredictable forest flights, complete with many direction changes to dodge trees, and accompanied by constant excited chatter. The author of this resource was quick to explain that the activity probably has a practical application in that it helps youngsters practice evasive maneuvers that would come in handy should predators be lurking about. However, and surprisingly, the expert also admitted the birds seemed to be having fun.

male red-bellied woodpecker in nest (Photo- Frederick Knapp, Creative Commons license)RBWs are monogamous—for the extent of a breeding season, that is (so perhaps it would be more accurate to say they are serial monogamists)—and both are actively involved in raising young.  They nest in hardwood and pine trees, along with the occasional fence post, by excavating a cavity or stealing one from other birds. What goes around comes around, though—or so says a timeworn adage; RBWs often lose their precious nest holes, in turn, to European (aka common) starlings (Sturnus vulgaris).

Assuming the pair can hang on to their home, the female lays two to six white eggs on a cushion of wood chip construction debris and incubates them for 12 days. The hatchlings are altricial, meaning they begin their lives naked, blind, and helpless. They don’t waste any time growing up, and are ready to leave the nest for a first tentative flight when they are 24—27 days old. Depending on the region, the adults may raise from one to three broods in a season.

red-bellied woodpecker at feeder (Photo: ehpien, Creative Commons license)Defending the homestead is a top priority during the child-rearing seasons, especially if the ‘hood includes a well-tended feeder (a gold mine for species able to digest seeds or suet). Even though most bird nestlings can’t tolerate seeds and need a diet composed largely of insects, when Mom and Dad can grab a high-calorie meal from the avian equivalent of a fast-food restaurant, they have extra time to hunt for the more illusive foods their offspring need to develop properly.

Since RBW territories range from 3 to 39 acres protecting the perimeter is far from a simple task, especially when feeding yourself and your family is a full-time job. So, naturally, breaches occur… but everyone trespasses and is trespassed against.  Border skirmishes are common but they rarely result in bloodshed. Research tells us that’s due, in part, to the fact that the intensity of defense behavior tends to decrease as an animal moves away from the center of its territory. Put another way, property rights become less important the farther you are from home. In most cases, both combatants throw in the towel long before there’s a knock-out.

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© 2012 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work; all you have to do is ask). Thanks to these photographers for making their work available through a Creative Commons license: [starting from the top] Brian Peterson (on the fence); Jason Paluck (male & female; red-bellied); Laura Gooch (red-headed); Frederic Knapp (in nest); ehpien (rbw @ feeder).

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