The Marsh Hawk

Last week, when I visited my friend Maria (my first bird teacher), I asked her what birds she would want to read about. I used her idea of writing about American Avocets for Seashore Saturday, but there was another bird she mentioned: the Northern Harrier. I’ve seen Northern Harriers on a handful of occasions. While fascinated by their spectacular aerial displays while hunting, I realized I didn’t know much about them. It turns out that Northern Harriers have some interesting characteristics that make them unique from other raptors. Here are 5 cool facts about the Northern Harrier.

• There are 13 species of Harriers worldwide, but the Northern Harrier is the sole representative in North America. It is part of the genus Circus, from the Greek word kirkos. This genus name refers to the fact that Harriers hunt for prey by circling over an area. Northern Harriers are usually found gliding over marshes (hence the nickname Marsh Hawk) low to the ground, but can also be found in other open areas throughout the continent.

A female Northern Harrier in flight (Image by Dan Pancamo via wikimedia commons)

• The shape of the Northern Harrier is unique among other raptors. They are slender with long tails and wings. In flight they hold their wings in a dihedral (or “v”) shape above their heads, similar to Turkey Vultures. They display sexual dimorphism, where the genders differ in appearance in addition to the sexual organs themselves. Male Northern Harriers are nicknamed “the gray ghost” and are pale overall. They have black wing tips that contrast their mainly white wings. Females are light brown with buffy underparts that are heavily streaked. Juveniles are dark brown with rufous underparts. All Northern Harriers feature a distinctive white patch on their rumps, which makes them easier to identify during flight.

Female and Male Northern Harriers (Image via Hawk Mountain Sanctuary)

• Northern Harriers are the most “owl-like” of all the hawks, although they are not directly related to owls. Like owls, these Harriers hunt both by sight and sound. Their faces are small and flat because they have “facial disks” of feathers in a circular pattern like owls do. The stiff feathers on their faces help direct sound to their ears, while gliding low helps them spot the prey that they hear. Although they hunt in a similar fashion, Harriers are diurnal (active during the day), while owls are nocturnal (active during the night).

Male Northern Harrier (Image by John Crawley via utahbirds.org)

• They are the only hawk-like birds to practice polygyny, where males mate with more than one female at a time. Northern Harriers typically have 2 to 3 mates, although some stay monogamous. Each female has her own nest and the male attends to each one individually. When food is abundant, a male can have up to 5 mates per season. According to Hawk Mountain Sanctuary’s website, there was one individual male who tended to 7 nest simultaneously!
• Northern Harriers can have over 5 different flight shapes. Many observers are surprised when they find them flying high, since they are usually seen lower to the ground. The best features to look for while trying to identify a Northern Harrier in flight is the white rump and long slender wings.