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Ferruginous Hawk

Buteo regalis

Length: 22 - 28 inches Wingspan: 52-60 inches Seasonality: Summer / All Seasons
ID Keys: Variable, with both light and dark morphs.  Yellow gape extending well below eye.  Largest of the Buteos.

Ferruginous Hawk - Buteo regalisThe Ferruginous Hawk is a large regal (the well-named Buteo regalis!) hawk of open western prairies.  They are the largest of the "Buteo" Hawks.  In historic times, the nest of the Ferruginous Hawk often used both bison bones in the structure and bison dung as part of a lining.  They are a species that seems less shy of human beings than some other Buteo hawks.  Unlike many raptor species, they will often allow for a surprisingly close view without flushing.

In South Dakota, Ferruginous Hawks are found in all seasons. Most range maps show them over-wintering southward from South Dakota, but they can be consistently found in parts of South Dakota during the winter months. Prairie Dogs seem to be a favored prey item in winter, and they are often found hanging around the edges of prairie dog towns.

Habitat:

A species of open spaces, they can be found in grassland, sagebrush plains, rangeland, or desert areas.

Diet:

Mostly small mammals, including ground squirrels, jackrabbits, gophers, rabbits, and mice.  Also eats some birds and reptiles.

Behavior:

Generally hunts while soaring, or by observing from a perch.   It can also often be seen sitting on the ground, where sometimes it will wait by a gopher or prairie dog hole for prey to surface.

Nesting:

April through June in South Dakota.  Most nests are built in trees, but they will also sometimes nest on cliffs or on the ground.  The nest is a large structure of built of sticks, lined with softer material.  Ferruginous Hawks often start with the nest of another species and build upon it. They will use cow dung (or traditionally, bison dung) to line the nest.  The female lays 2 to 5 eggs, and both parents help to incubate them.  Upon hatching, the female initially stays with the young while the male hunts for food and brings it back to the nest.  As the chicks get older, both parents will hunt for food.

Song:

The most commonly heard vocalization is a harsh, screaming key-ahh, or kaah-kaah. 

Migration:

Ferruiginous Hawks are generally a short-distance migrant, with some birds at the northern end of it's normal range migrating southward in the winter. Many range maps show Ferruginous Hawks over-wintering in areas southward from South Dakota (including the data used for the map below), but you can typically find them here during the winter months.

Interactive eBird Map:

 Click here to access an interactive eBird map of Ferruginous Hawk sightings

Similar Species:

 Depending on morph and age, in South Dakota, Ferruginous Hawks are most likely to be confused with the Red-Tailed Hawk, Rough-Legged Hawk, or Swainson's HawkClick here for a page that describes differences between the "Buteo" hawk species, and identification keys for each. With a number of color morphs, and plumages differing between immature and adult birds, the variety of plumage patterns makes it difficult to list all identification keys here. Here are specific tips for differentiating Ferruginous from Red-tailed, Swainson's, and Rough-legged Hawks, with a focus on structural and other elements that are more consistent regardless of color morph.

Red-tailed Hawk 32 - Buteo jamaicensis Red-tailed Hawk - Buteo jamaicensis Rough-legged Hawk 27 - Buteo lagopus Swainson's Hawk 8 - Buteo swainsoni
Red-tailed Hawk (immature) Red-tailed Hawk Rough-legged Hawk Swainson's Hawk (light morph)

Conservation Status:

Ferruginous Hawks have disappeared or plummeted in number in much of their former range, primarily due to habitat loss.  However, overall populations remain relatively strong, and they are found over a wide geographic region.  The IUCN lists them as a species of "Least Concern".

South Dakota "Hotspot":

My favorite location to find them are around prairie dog towns on the Fort Pierre National Grasslands during the winter months. However, the key isn't necessarily the geography and area of the grasslands themselves, but the presence of the prairie dog towns. They seem to hang out around most of the prairie dog towns in the western half of South Dakota in the winter.

Further Information:

Photo Information:

January 1st, 2013 - Near Kennebec, South Dakota - Terry Sohl

Additional Photos:

Click on the image chips or text links below for additional, higher-resolution Ferruginous Hawk photos.

Audio File Credits:

1Andrew Spencer, XC77780. Accessible at www.xeno-canto.org/77780

 

Click on the range map for a higher-resolution view
Ferruginous Hawk - Range Map
South Dakota Status: Uncommon migrant and summer resident in most of the state, except absent in the southeast. Uncommon in winter, primarily in southern half of the state, but an overwintering presence seems to be on the increase.

Additional Ferruginous Hawk Photos
Click for a higher-resolution version of these photos
 Ferruginous Hawk 1 - Buteo regalisFerruginous Hawk 2 - Buteo regalisFerruginous Hawk 3 - Buteo regalisFerruginous Hawk 4 - Buteo regalisFerruginous Hawk 5 - Buteo regalisFerruginous Hawk 6 - Buteo regalisFerruginous Hawk 7 - Buteo regalisFerruginous Hawk 8 - Buteo regalisFerruginous Hawk 9 - Buteo regalisFerruginous Hawk 10 - Buteo regalisFerruginous Hawk 11 - Buteo regalisFerruginous Hawk 12 - Buteo regalisFerruginous Hawk 13 - Buteo regalisFerruginous Hawk 14 - Buteo regalisFerruginous Hawk 15 - Buteo regalisFerruginous Hawk 16 - Buteo regalisFerruginous Hawk 17 - Buteo regalisFerruginous Hawk 18 - Buteo regalisFerruginous Hawk 19 - Buteo regalisFerruginous Hawk 20 - Buteo regalisFerruginous Hawk 21 - Buteo regalisFerruginous Hawk 22 - Buteo regalisFerruginous Hawk 23 - Buteo regalisFerruginous Hawk 24 - Buteo regalisFerruginous Hawk 25 - Buteo regalisFerruginous Hawk 26 - Buteo regalisFerruginous Hawk 27 - Buteo regalisFerruginous Hawk 28 - Buteo regalisFerruginous Hawk 29 - Buteo regalisFerruginous Hawk 30 - Buteo regalisFerruginous Hawk 31 - Buteo regalis