More Foothills Raptors

by Dan Weisz

I seem to keep bumping into various raptors this week.  Some are specific birds we’ve seen before while some are new birds.

Last week, we saw a Red-tailed Hawk pair together and then saw the female selecting a twig from a mesquite tree for their nest.  Several days later, I saw the same pair again sitting on neighboring telephone poles.  As soon as I pulled the car over to watch, both birds took off and began to soar together.  Suddenly, one took off heading south carrying another piece of their future nest while the other bird just continued to soar higher and higher.  The dark leading edge of the bird’s wing is called a “patagial” mark.  That is a distinctive feature of red-tailed hawks and an easy way to identify a soaring hawk as a red-tail.

The neighborhood Peregrine Falcons continue to winter here.  On one recent morning, one was seen preening along Swan Road.  Preening is a bird’s way to keep their feathers groomed, in the best condition, and positioned correctly.  Most birds preen several times a day to align each feather in its optimum position and to remove dust, dirt, or parasites.  This was taken on an overcast morning so the sky behind the bird is white.

And the preening continued…..

Later this week, I found the peregrine again, this time working on breakfast early one morning.  Breakfast, likely a mourning dove, had already been cleaned by the time I arrived, and the peregrine continued to dine.

I’m offering the closeup below so you can see how thoroughly the Peregrine had cleaned its prey.  

This above closeup also lets you see an unusual structure inside the falcon’s nostril.  Notice that little ‘bump’?  Peregrine Falcons are known for their high speed stoops when they dive from great heights to surprise and catch their prey.  They can reach speeds of over 240 miles per hour.  At that speed, the air pressure on their nostrils would make it impossible to breathe.  The bony structure, or cone, inside their nostrils breaks up the air pressure allowing them to breath at that very high speed.  Jet engines have a smilier structure called an inlet cone.  As planes got faster and faster, the engines started choking out at certain speeds.  Air was not able to enter the engine’s opening.  Researchers looked at the falcon’s nostrils, saw that small cone, and fashioned something similar.  Human invention often follows an animal adaptation.

Image result for inlet cone on a passenger plane

I’ve noticed a Harris’s Hawk family along River Road.  This is one of what may be over 60 families living in the Tucson area.  Here, one hawk sits at the very top of a tree watching over its territory.  Harris’ Hawks lack facial feathers between their nostrils and eyes showing a large amount of yellow skin there.  Their dark chocolate color and brick-red shoulders are distinctive along with a white rump patch and a (mostly hidden here) white-tipped tail.  I plan to revisit this family over the year so we can look forward to more pictures of the same group.

I wish the tiny branch wasn’t in front of this bird, but I wanted you to see the difference between an adult Harris’s Hawk (above) and the juvenile below with its heavily streaked underparts.  The bare skin on its face is clearly visible as is the white rump patch.

I came home yesterday to see a Red-tailed Hawk sitting atop a neighbor’s tree.  I have never seen one there before so I took it as sign to focus on raptors in today’s email.  Red-tails’ plumage is highly variable but that body shape and belly band are typical.  Its hold on this tree appears very shaky but it seems to have a death grip on one branch.