Birds

The Rusty Squirrel-Hawk AKA Ferruginous Hawk

December 19, 2012 by Larry 12 Comments

Ferruginous Hawk

The Ferruginous Hawk (Buteo regalis) is truly a regal bird. Sporting a 56 inch wingspan, it is the largest of the Buteos. They inhabit the grasslands, shrub steppes, and deserts of western and central North America. Click on photos for full sized images.

Ferruginous Hawks were known as Rusty Squirrel-Hawks back in the 1800’s and they exist in both a light and dark morph. I took a ride up to the Fall River Valley back in October and spotted both morphs in the large grasslands where we also usually see Rough-legged Hawks and Prairie Falcons. This is the light morph.

Ferruginous Hawk

They are often seen on the ground since their prey consists mainly of rabbit, prairie dog and, you guessed it, ground squirrel.

Ferruginous Hawk

And this is what the dark morph looks like.

Ferruginous Hawk

Note the long yellow gape, a characteristic field mark of this species.

Ferruginous Hawk

For the past five years I have been fortunate to have a Ferruginous Hawk wintering near a farm in a grassland area below the foothills where I live.

Ferruginous Hawk

Ferruginous Hawks were petitioned for listing under the federal Endangered Species Act in 1991 but rejected; currently they are listed as a Category 2 Species by the U.S. Fish and Wildlife Service and as a Sensitive Species by the Bureau of Land Management1. They are listed as vulnerable in Canada.

Ferruginous Hawk

A study conducted by Richard Olendorff, working for the U.S. Bureau of Land Management, suggested that management measures aimed at maintaining current population numbers should include enhancing nest substrates, maintaining prey populations, and mitigating development impacts from mining, pipeline construction, and urbanization2.

Ferruginous Hawk

Obviously more research needs to be done on this magnificent raptor. The latest study I found was a migration study which included Canada, the United States and Mexico done by the Rocky Mountain Bird Observatory.

I hope to see my winter visitor for many years to come as these birds can live 20 years in the wild! In the meantime, I found a cool video of the Ferruginous Hawk in slow motion. It is an education bird from the Arizona-Sonora Desert Museum’s Raptor Free Flight program. Enjoy!

httpv://www.youtube.com/watch?v=q0lQzVLi9bw

References: 1Birds of North America Online, 2Olendorff, R. R. 1993. Status, biology, and management of Ferruginous Hawks: a review. Raptor Res. and Tech. Asst. Cen., Spec. Rep. U.S. Dep. Interior, Bur. Land Manage. Boise, ID.

Written by Larry
Larry Jordan was introduced to birding after moving to northern California where he was overwhelmed by the local wildlife, forcing him to buy his first field guide just to be able to identify all the species visiting his yard. Building birdhouses and putting up feeders brought the avian fauna even closer and he was hooked. Larry wanted to share his passion for birds and conservation and hatched The Birder's Report in September of 2007. His recent focus is on bringing the Western Burrowing Owl back to life in California where he also monitors several bluebird trails. He is a BirdLife Species Champion and contributes to several other conservation efforts, being the webmaster for Wintu Audubon Society and the Director of Strategic Initiatives for the Urban Bird Foundation. He is now co-founder of a movement to create a new revenue stream for our National Wildlife Refuges with a Wildlife Conservation Pass.