Sunday, December 27, 2020

Red Crossbill


Red Crossbill aka. Common Crossbill
Skylawn Memorial Park, San Mateo, California, USA
August 2020
Member of the Finch Family
§A Warp of Crossbills§

~True Bird Fact~ Let's talk about that remarkable bill for a second! It may look a little bit like a cartoon bird that has been hit in the face, but that bill is actually a specialized tool for getting at the type of food this bird most likes to eat- seeds. Specifically, the seeds of coniferous plants, but they do go for other seeds as well. You see the pounds of pressure exerted by a bite down is much greater than pressure you can exert with a mouth opening. This is why it's relatively easy to hold a gator's mouth closed with your hands, but you've got very little chance of getting their grip off of you (was this example too "Florida Man"?). So anyway, this bird needs to be able to pry apart while biting down.

This evolutionary adaptation leads to a lot of very specific behavior- unlike most baby birds, crossbill young eat seeds as well, instead of bugs. Furthermore, different crossbill subspecies have beaks that are slightly specialized for different kinds of seed cones. How much do these birds depend on seeds? So much so that their breeding cycle is not seasonal, but is instead tied to availability of a major source of seeds. This leads to occasional 'irruptions', which is how I was able to see this relatively rare bird locally. When conifer populations don't produce enough seeds, these birds travel south, well outside of their usual range in great number. 

Something else I wanted to note about the crossbill is that whole subspecies thing- there are quite a few of them, and already one (the Cassia Crossbill) has been elevated to it's own species. It seems likely, based on differences in appearance, call, and breeding, that several of these subspecies will be declared their own distinct bird at some point, despite being nearly impossible to tell apart. This information, reader, hangs over me like a Sword of Damocles, taunting me with the information that in the near to distant future I will almost certainly no longer be able to tell what type of bird this is. I will enjoy the Red Crossbill while it lasts.

left-male, right-females

Some additional shots of the beautiful Buddha statue that these birds seem to be congregating around. I think given this information you would be safe in assuming these birds are either 1) Buddhists or 2) Of a divine nature.

It appears to be associated with San Francisco's True Buddha School Veil Parasol Temple, although I'm not totally sure in what capacity. The whole cemetery is very beautiful, so check it out if you get a chance.