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Life in Nature: Winter’s winged majesty

The raptor with pants: the Ferruginous Hawk

Posted 1/7/26

While many birds fly south for the winter, others flock to Colorado

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Life in Nature: Winter’s winged majesty

The raptor with pants: the Ferruginous Hawk

Posted

WELD COUNTY — While we haven’t really felt it much, winter has arrived here in the foothills.

Typically, summer and fall find me spending much of my photography time in the high country with the larger of our four-legged animals. As the seasons shift, so do my own migration patterns, as I head eastward in search of life on the wing. 

Living in an area that sees such a long winter, common sense might imply the concept that migrations move wildlife toward warmer climes. When it comes to my specific winter quarry, the raptors, this is not always the case.

We bid farewell to our Osprey, Swainson’s Hawks, and others in autumn, but winter sees the arrival of more bald eagles escaping harsher winters in the north. We also see the subjects of this week’s article, the beautiful Ferruginous Hawks.

Ferruginous hawks are the largest hawks found in North America. They come in at an average length of 24 inches with a wingspan of nearly five feet. By comparison, Red Tailed hawks, the next in size and most common in North America, average about 18 inches in length with a wingspan of about four feet.

In attempting to identify them, you will see that the most striking differences other than size are coloration, leg feathers, and cere (the fleshy area at the base of a bird’s beak) colors.

These beauties have a mottled brown upper side of their body, with a strikingly white underbody with few markings other than mottled brown on their legs and under the wings. As for their leg feathers, they are the only hawks in North America other than Rough Leggeds to “wear pants.” That is to say, their leg feathers reach all the way to their talons. 

Regarding the cere, it is a brilliant yellow, similar to that of a Golden Eagle.

I mention coloring, but it should be noted that, like many species of hawks, they tend to display both light and dark morphs. The darker morph ferruginous are just that, having a significantly darker full body coloring, with white only on the outer half of their wing bottoms.

Morphing occurs as an adaptation to confuse prey. While a prey animal might become accustomed to seeing a certain shape and color combination that identifies their predator, morphing allows the predator to better camouflage its presence.

This can certainly make identification a bit trickier for both the prey and human observers.

Ferrugs (as they are commonly called) prefer life on the prairie. While Colorado is home to nesting pairs that live here year round in the easternmost regions of the state, most tend to head north for the summer.

Like most hawks, their preferred diet is rodents, along with snakes and, occasionally, smaller reptiles. While they can take on something as large as a jackrabbit, much of their diet consists of ground squirrels and prairie dogs.

While these hawks do hunt from the air like most raptors, they also have been observed hunting on the ground. Having found an active den, they will sometimes simply land and stand near an entrance out of sight from the inside and wait for their quarry to emerge.

Even more unique in their ground-hunting tactics, they have been known to gather in groups of five to 10 birds at a prairie dog colony.

Taking prey tends to cause a competitive feeding frenzy, with the birds hopping around and flapping their wings to display dominance. This can sometimes attract more hawks, and occasionally even Golden and Bald Eagles, to the fracas.

This co-habitation with other hawks is also common in their roosting habits. Unlike many raptors who tend to stay solitary or in pairs, ferrugs sometimes gather in flocks of as many as 100, and have even been known to include Golden Eagles as well.

If you happen to find yourself making your way about the pastureland and plains east of the mountains, keep your eyes peeled for these striking birds. Like most other prairie raptors, their hunting from elevated positions tends to have them spotted on telephone poles and power line towers due to the scarcity of trees.

Their bright white bellies (if not a dark morph) will be an easy giveaway to enjoying the company of these grand large and majestic hawks!

Helpful sources for this article came from allaboutbirds.org/guide/Ferruginous_Hawk/overview and ornithology.com/avian-color-morphs. 

For additional information about James DeWalt Photography, check out  jamesdewaltphotography.com.