January 20, 2015 Flying Free

Flying Free

A Visit to the Green Hills of Central California 

On a recent drive in the Central Valley where we were monitoring Golden Eagles, a falconer friend and I saw a number of wonderful raptors, among them a gorgeous Ferruginous Hawk – the largest of the North American buteo hawks and a winter visitor for this area. These are regal birds, the most common variant having pale overall feathering with strong accent markings. They have a particularly glowering eye (owing to a deep supraorbital ridge or brow, like an eagle’s) and an unusually large mouth opening (gape). They also possess exceedingly powerful feet. The toes may not be long, but oh, they are strong.

Wild Ferruginous Hawk, Central Valley, CA
Ferruginous Hawk, Buteo regalis, in the Central Valley, CA. Many large raptors seek the vantage of power poles where they can both see prey and spot danger. The power poles also often present a hazard to the large birds – the possibility of electrocution.

 

These birds do not breed in California, but in more central and northern US prairie habitats, where they build large nests on the ground or in low bushes. They come down to us to when the prairie winds are biting, and use those power-feet to capture ground squirrels and jackrabbits, which abound in the Valley. These mammals, well armed and strong themselves, are also the favorite prey of the Golden Eagles in the area, and it is not unlikely that we may see some hunting-territory squabbles in the course of future monitoring trips.

Our wild one bumped off the pole and was gone in minutes
Our wild one bumped off the pole and was gone in minutes

 

We don’t often notice it, because animals are more subtle and careful than we are, but nothing is safe out in the wild, not for a minute. No creature, not even the predator, can let its fierce intent and brilliant attention waver, not for a blink, or other killers awaiting just such an opportunity will seize the moment.

Our prize of the morning – even more exciting than the two Goldens soaring up and over the green ranch hills – was an enormous female Prairie Falcon, perched on a power pole where she could keep watch for potential dinner.

prfa ready for web

I had never seen one in the wild before, and oh, she is beautiful! She tolerated our approach in the car well enough for me to get a nice series of photographs.

Looking right at us.

Prairie Falcon, Falco mexicanus, looking right at us.

These birds do breed in Northern California, most famously in the coastal caves and cliffs of Pinnacles National Monument south of San Francisco, and they love the prey-rich valley in winter. Prairies are strictly North American falcons, and unlike the more cosmopolitan Peregrines, prey on mammals as well as birds. This one has the feet to prove it. Look at her long powerful toes and sharp talons (picture below) – they can easily subdue a large rabbit, and her sharp, notched beak can neatly sever the spinal cord, thus sparing her a dangerous struggle.

prfa flying for web

 

Falcons display a noticeable size difference between male and female with little overlap, so she is surely she. Note, in the photos above, her nice large head and the broad shoulders. (Few raptors show gender color or feathering differences.)

The Ferruginous females, on the other hand, like most buteo hawks, have some overlap in weight ranges with the males and they are not easily distinguished at a distance. Or even up close, sometimes. The California Raptor Center in Davis had a resident non-releasable Ferruginous for many years, named Thor. He had flown into a train near Reno, Nevada, and survived the collision. Thor could not fly after his recovery, and lived at the Raptor Center for many years. On his death, the vets discovered he was a (small) she.

Thor, note drooping wing from his collision with a train,.

Thor, note twisted right wing from his collision with a train. Also not the thick toes and long talons.

 

 

Portrait of Thor - note the bony ridge over the eye and the broad gape.

Portrait of Thor – note the bony ridge over the eye and the broad gape of the mouth.

Anyone care to scroll up to the first pictures and guess the wild one’s gender?

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