More tales (and tails) of the Agua Caliente nursery, May 2017

5/21/2017

Mamma Cooper's Hawk feeding one of her nestlings, May 18, 2017

The middle of May in Tucson has turned out to be cooler than usual - partial compensation for some of the really hot days we had earlier in the year. On the Thursday May 18th Agua Caliente birding walk we caught up with the nursery. Over the past two months we have seen nests for Anna's Hummingbirds, Vermilion Flycatchers, the Great Horned Owl, Curved-bill Thrashers, the Beardless Tyrannulet, Ravens, and Cooper's Hawks.

The Cooper's Hawk's nest is high in a Cottonwood tree close to the guest house and the path that leads to the western ponds. From the path, looking waaaay up and toward the south, you can see the nest. There are at least two nestlings, here being fed a fresh kill by the mother, images above and below. In the image below it is not clear if the chick is full, or offering food back to mom. The kill is off to the mother's left side, right side of the frame, and as we watched she ducked her head out of frame to get pieces she then fed to the young.

Below, a pause in the feeding.

I suspect we were catching all this toward the end of the meal. The mother finally picks up the whole kill, and dangles it above the young. Perhaps she is showing the chicks what they will need to deal with as adults ("You're not going to get this kind of service forever!") , or this could just be a "last call!"

In any event, after a minute or so she flies off with the kill, perhaps to leave it with the male who generally sits watching the nest from an adjacent tree. She returns, and settles down on the brood, keeping them warm and protected.

Ravens defend their nest against a cruising Red-Tail Hawk

Ravens are also nesting, just north of the Cooper's Hawk nest. The nest itself is tough to see from the ground, but it is there, and likely has nestlings. As we were walking west on the path to the western ponds, just as we cleared the cover of the mesquite bosque, we spotted a soaring Red-tailed Hawk to the south. This is likely a immature male, with all the markings of a Red-tailed, but without a red tail. Image below:

As the hawk flew closer to us, he was intercepted by first one and then a second Raven, on high alert for any raptors that might raid their nest. Below, the hawk spots one of his attackers.

The Ravens rapidly went on the attack, doing aerobatics that looked at times incompatible with flight. Below are three images showing the Raven attacking the hawk feet first.

The second Raven got into the fight quickly, sometimes hanging back, sometimes getting closer. Below the Ravens are 2 on 1 against the hawk.

The hawk moved north and west fairly quickly, getting out of our range, and away from the Raven's nest. They appeared to break off the flight. Score another point for Raven homeland defense!

For the photo geeks: All images captured with a Canon 7D Mark II with a Sigma 150-600mm C series. I was set up for shooting songbirds at ground level when the Red-tailed hawk was spotted. I did manage to change focus settings from One Shot to AI Servo, and switched my focus point from center, single point to the center grid. These settings worked pretty well for the rapid movement overhead. The 7D was set at aperture priority, f 8.0, ISO fixed at 200. Shutter speeds varied between 1/400 and 1/640 sec. If I had more time, I would have moved the ISO up a bit, and aperture down a bit to get faster shutter speeds. Frames 1,2,3,5 and 6 were at 600 mm, frame 4 at 275mm. I had to zoom out as the birds came right overhead. Shutter was set on High Speed Continuous, which with the 7D captures up to 10 frames/second, slowing down as the buffer fills. I shot 1800 frames total on the 18th, over 200 were of this encounter. These 6 were the best. Post-production processing with Lightroom CC [version 6], with considerable cropping on most images and generous use of the Clarity and Sharpening sliders.