- Written by Clyde McMillan-Gamber Clyde McMillan-Gamber
In winter, over several years, I’ve seen wintering northern harriers, which are a kind of hawk, and short-eared owls hunting mice and small birds in marshes and tall-grass fields in southeastern Pennsylvania, including at Middle Creek Wildlife Area and Gettysburg National Park.
Harriers hunt by day, and short-ears do so from late in the afternoon into the night. And both kinds of these handsome, feathered predators are entertaining to watch hunting. Occasionally they are seen in the same place at the same time.
These beautiful, camouflaged predators have the same job in the same habitats but at different times of day, which reduces competition between them for food.
It’s interesting how a species from each family of birds diverges from its relatives to exploit a habitat their cousins don’t. But that same kind of bird converges with a non-relative in the same environment.
Each habitat molds its occupants into being similar in body form and habits to be able to thrive in it. Most birds, all bats, and certain insect species have wings, which enable them to fly as part of their survival.
Harriers and short-ears have characteristics in common because of the habitats they share. Both cruise slowly, gracefully, and into the wind for lift and flight control when hunting. The delightful flights of both raptors, which are low to the ground, are inspiring to see.
Both the hawks and owls watch and listen closely for any indication of prey. And when a victim is perceived, both feathered predators drop abruptly into the tall vegetation to grab it in their sharp talons.
Harriers hunt with several wing beats alternating with short glides. They also hover on beating wings, into the wind, over one spot if they sense prey. These hawks are identified in flight by their large, white rump feathering.
The attractive owls begin hunting late in winter afternoons. They fly silently and moth-like, on quick, irregular wingbeats and short glides. Their tawny plumage identifies them when they are in flight.
Wintering harriers and short-ears are not common in southeastern Pennsylvania. And they don’t nest here. There are few tall-grass fields here and no marshes large enough to attract them. But these adaptable birds do nest in some deserted landfills and strip mines that were planted with tall grass to help hold down — and enrich — the remaining soil.
Northern harriers and short-eared owls are beautiful, graceful birds of prey that share marshes and tall-grass fields to hunt prey and rear offspring. But we only see them in southeastern Pennsylvania during winter when they hunt mice and small birds in tall-grass and overgrown, weedy fields.
Both these attractive species are an inspiring pleasure to watch hunting low over marshes and fields.
Clyde McMillan-Gamber is a retired Lancaster County Parks naturalist.