Another Encounter With The Antelope Island Prairie Falcon

Two days ago we located the Prairie Falcon on the causeway once again.  This bird spends most of its time on the island itself but occasionally ventures onto the causeway to hunt ducks.  I’m quite sure, as are others who are more falcon knowledgeable than I, that it’s the same individual in all of my recent Prairie Falcon posts.

Usually I complain about not being able to get close enough to my subjects but here I had the opposite problem.  The only way I could even see this bird was from very close.  From any further away the falcon was completely obstructed by the road edge and the vegetation growing there.  The first two images are essentially full frame (very little crop) and that’s without my tc attached, so the falcon is too tight in the frame but this post is more about falcon adaptations than it is about aesthetics anyway.

 

 1/1600, f/9, ISO 500, 500 f/4, natural light, not baited, set up or called in

This bird was a mess!  It had apparently just finished dining on duck so it was wet, blood encrusted and disheveled, with tidbits still clinging to feet and beak.  The bird is meticulously cleaning and scratching its beak with those impressive talons, which seems to me to be about like picking one’s teeth with a Bowie knife.

 

 

  1/1600, f/9, ISO 500, 500 f/4, natural light, not baited, set up or called in

But what I found particularly interesting about many of the images I took of this bird was the good look at the well-defined and bulging crop.   The crop is essentially a food storing organ that is an enlarged and muscular part of the esophagus.  One of its advantages is that it allows the bird to quickly eat copious amounts of food and then fly off to digest it in peace, rather than have to be concerned about predators on the ground or competing raptors attempting to steal the meal.  Most raptors have a crop, although owls do not.  Which makes me curious – could the reason for the lack of a crop in owls be the fact that owls typically hunt at night when there’d likely be little, if any, competition from the diurnal raptors?   I might have to investigate this a little…

 

 

Because I was so close to this bird, a heavy crop of the previous image allows a good look at the falcon “nostril cone”.   Falcons are incredibly fast flyers.  In a stoop (a powered dive to attack prey), the Peregrine Falcon has been clocked at over 200 mph and many other falcon species aren’t far behind.  At those velocities, air rushing into the nostrils would cause breathing problems so falcons have evolved these “cones” at the entrance to their nostrils to disrupt the air flow and slow it down.

 

 

Public Domain image, from Wikipedia

Engineers faced a similar problem when supersonic aircraft were being developed.  At those speeds air would rush into the jet engines so fast that proper air flow and air pressure into the compressors and turbines could not be maintained.   So developers looked at falcons to see how they solved the problem and used the same trick that they do – cone-shaped structures in front of the intakes of the engines to slow the airflow down.

This is the famous Lockheed SR-71 Blackbird in flight over the Sierra Mountains.  The cones can clearly be seen protruding in front of the engine intakes.  The positions of these cones are adjusted in flight, depending on speed.  At relatively slow speeds, as in this photo, the cones protrude far out in front of the engine but as supersonic velocities are approached the cones move further back into the engine.

Just another example of humans looking to nature for inspiration in solving a practical problem.

Ron