Ferruginous Hawks in Idaho

While working in Boise, Idaho this summer, we came across many Ferruginous Hawks in our travels.  Ferruginous Hawks are the largest hawk in North America.  While they exist in both light and dark phases, I only saw light phases this summer in Idaho.  I've seen dark phases in Nebraska, back in the days when a 400mm lens was a far away thought, so no good photos!  (just gives me a reason to go back!)  Like most raptors of the mid-west and west, Ferruginous hawks main prey are ground squirrels and prairie dogs. If you find yourself in a colony of either of these rodents, chances are a Ferruginous Hawk isn't very far away, and is likely plotting his next attack on another cute-and-furry.  A very important thing to remember about Ferruginous Hawks is that they are EXTREMELY sensitive to disturbances at their nests. NEVER approach a Ferruginous Hawk nest, as they are likely to abandon it.

This past summer, our Long-billed Curlew study area had at least one nesting pair of Ferruginous Hawks, and others were attracted by the abundant supply of ground squirrels.  While roaming the rolling hills, it was a common occurrence to be circled by a hunting Ferruginous Hawk, especially on days when you thought it was a good idea to leave the camera in the truck. We found this nest on one of our first days of work in April; clearly it has been used for many years!  When we went back to check on it in June, the nest had 2 fluffy babies on it with mom nearby, while dad was defending their territory from an over abundance of Swainson's Hawks.

Ferruginous Hawk (female) at nest with 2 chicks;

note rufous shoulders and dark back of adult

Ferruginous Hawk - adult male

Note red leggings and rufous underwing markings,

in addition to wide "gape"

Ferruginous Hawk - adult male

In the agricultural fields between Boise and the Snake River Birds of Prey National Conservation Area, we found this nest in April. By June, two large fledglings were literally jumping all over the nest, stretching their wings, and getting ready to jump.

Ferruginous Hawks - 2 fledglings and adult

Probably the best place to photograph Ferruginous Hawks was the Snake River Birds of Prey National Conservation Area.  This place is huge and also has an abundance of ground squirrels, which are always an attractive food source for opportunistic raptors. This adult Ferruginous Hawk was one of the most beautiful birds I have seen in my life! Within about 600 meters of this bird, there was also a Rough-legged Hawk, a Golden Eagle, a Prairie Falcon, and a Swainson's Hawk...which is why you should start planning your trip to the Snake River Birds of Prey Area! 

Adult (left)                                          Juvenile (right)

Note red "leggings" of adult (not seen on juvenile),

appearing as dark "V" when viewed from below

Adult (left)                              Juvenile (right)

Juvenile lacks red "leggings" and has a lightly banded tail.

Juvenile appears very pale/white at a distance, as it lacks most rufous markings on

underwings and shoulders as seen in adult. Wide "gape" visible on both.



Distinct "shape" of Ferruginous Hawk when flapping is visible at quite a distance

Ferruginous Hawk - juvenile

The photos of the perched bird below were taken in June at the Snake River Birds of Prey Area.

A nest was visible in the distance on transmission line towers.

Ferruginous Hawk - adult

Ferruginous Hawk - adult

Note large "gape"

Ferruginous Hawk - adult

Note rufous shoulders and dark back creating a "two-toned" appearance

This post is a part of WORLD BIRD WEDNESDAY!!!

Also, can't get enough raptors? Check out Jerry Jourdan's post about his "Hawkfest 2011" where he witnessed an absolutely huge flight of Broad-winged Hawks!