Nature: Ferocious hunters, northern harriers are also incredible aerial performers

 

Nature: Ferocious hunters, northern harriers are also incredible aerial performers

In the 1960s, British aviation company Hawker Siddeley developed an innovative jet capable of vertical takeoffs and landings. This formidable war craft was dubbed the Harrier. Its name was inspired by the hen harrier, an agile raptor capable of impressive aerial acrobatics.

The jet’s namesake occurs here in Ohio. Well, sort of. Until recently, the Eurasian hen harrier and New World northern harrier were considered the same species. However, the world of taxonomy is ever-shifting and ornithologists finally decreed them separate species based on genetics and appearance. Only northern harriers are found in Ohio.

As impressive as the multimillion dollar jet is, it’s got nothing on the bird. Just ask the voles that it hunts.

I recently spent a frosty blue morning observing harriers at Killdeer Plains, a wildlife area in Harpster, Ohio, an hour north of Columbus. A major goal was to get sharp in-flight images. Photographing one of those jets would be far easier. The crafty raptors don’t miss anything and shy away from people.

Fortunately, my field tactics worked and I was able to get some passable images, one of which accompanies this column. Even if I had met with photographic failure, the trip would have been a success.

Northern harriers are beautiful birds, both male and female. Sexual dimorphism is pronounced. The more commonly seen females are significantly larger and dark brown to bright cinnamon. Both sexes have conspicuous white rumps and hold their wings in a dihedral — above parallel thus forming a V-shape.

The comparatively dainty male is sometimes termed “gray ghost”. It is a beautiful pearl-gray color and appears like a ghostly wraith as it floats about the meadows.

Up to eight harriers hunted in nearby fields, offering a tutorial in harrier hunting techniques. This raptor has long wings and tail, the better for instant aerial transitions. A hunting harrier quarters low over the ground, the better to surprise potential prey.

The prey — mostly small rodents — try to counter the enemy by crafting vegetative bunkers. Meadow voles are probably the most common prey here and in many areas. A chunky mouse-like mammal, voles are essentially sausages with legs and raptors covet them.

To better protect themselves, voles create runways — tunnels of grasses in which they can move while avoiding visual detection. Even that strategy doesn’t thwart the technologically advanced harrier. These raptors have evolved conical feathered facial disks which give them a remarkably owl-like appearance. Thus, their hearing is enhanced such that they can hear the rodents scurrying in their runways.

Many times, I have seen harriers pounce repeatedly, springing back into the air with grasses caught in their talons, only to immediately drop again. They are probably hunting mostly by sound, dropping on the runway and trying to seize the vole sight unseen.

Oftentimes they do, but the voles also frequently elude them.

Ohio is at the southern limits of the northern harrier’s breeding range, which stretches from Alaska to Newfoundland. While many winter here, few remain to breed.

Nonetheless one can occasionally witness the spectacular courtship flights. Performed primarily by males, this sky-dancing involves fast, deep U-shaped dives. The harrier strafes the ground before shooting high aloft, nearly stalling at the apogee. Wings flailing, it’ll barrel-roll and drop back toward the ground and repeat the circuit over and over. I’d like to see a harrier jet try that.

A great place to observe harriers locally is the aptly named Harrier Trail at Battelle Darby Metro Park. I’ve hiked this trail numerous times and don’t think I’ve ever missed seeing one, at least from October through March. Park information is at: https://bit.ly/3t9bBS2

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.