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Posts Tagged ‘Red-tailed Hawk’

A friend of mine has been volunteering with the National Park Service to track the nesting activities of raptors in the Presidio in San Francisco, CA for the past twenty years. There are four species of bird of prey that nest in the park. They are Red-tailed Hawk, Red-shouldered Hawk, Cooper’s Hawk, and Great Horned Owl.

Information that has been collected include where these birds nest, how many nest in the park, when stages of nesting (breeding, egg laying, incubation, etc.) occur, how many chick fledge from each nest, etc.

This project has taken a wonderful turn this year with the installation of nest cams! My friend, and others, have been working with the Park Service to get funding to purchase and install nest live-cams on some of the active nests. One of the first such cams has now been installed on a Red-tailed Hawk nest that has been built between the branches of a Blue Gum Eucalyptus Tree. The live-stream of this nest cam can be found on YouTube HERE.

RTHA Nest Cam Capture

Male Red-tailed Hawk in the Presidio, San Francisco, CA incubating the one egg that had been laid at this point. Note thin, black barring that are restricted to near the base of the tail.

The pair of Red-tailed Hawks have laid one white, and lightly speckled egg in the nest as of 3/7/2018. The male and female can be distinguished by a few characteristics. The best is by tail pattern. The male has a few, very thin black bars on its red tail. These bars are limited to the base of the tail. The female, on the other hand, has those thin black bars on the tail that extend just about all the way down to the black subterminal band near the tail tip. Beyond these tail pattern differences, the male and female have different molt patterns on the secondary flight feathers, the male is slightly smaller than the female, and the male is banded!

RTHA Nest Cam Capture F

Female Red-tailed Hawk in the Presidio, San Francisco, CA incubating the one egg that had been laid at this point. Note the thin, black barring that extend all the way to the subterminal tail band.

I have already noticed a few interesting things after only checking in on the nest for a couple of days. One is that when the the male comes to the nest to give the female a break, he sometimes brings nesting materials to add to the nest. He does this even though the nest is complete and an egg has been laid.

So far, about 60 people have been watching the nest at any given time. I am sure that this number will go up, and it will be great to push it as high as possible, since I am also sure that the Park Service will be more inclined to install more live-cams if the public response is positive and strong. So watch the Red-tailed Hawks and see what is going on at  the nest!

 

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A recent research trip took me into the mountains south of Soda Springs, CA.  As I walked along the edges of wet mountain meadows and through stands of huge Incense Cedars, I heard the call of a Red-tailed Hawk.  I looked up to see a single bird souring above me.  As I watched the bird, I heard another Red-tailed Hawk scream.  When I looked higher, I saw two more Red-tailed Hawks circling together much higher than the first.  The pair were both giving their long harsh screams over and over again, and then they both folded their wings and tipped downwards, dropping into the most spectacular, high-speed, tandem, power dive I have ever seen!  The pair plunged down upon the first bird, who was apparently an intruder on the territory of the pair.  The drop must have been at least 1000 ft.  The pair of hawks sped just past intruder, and dipped below taking another pass that the fleeing intruder as they looped back up above it.  The pair then continued to pursue the intruder, diving on it periodically, for as long as I could still see the birds before they dropped into a valley and out of my sight.  A spectacular display and a stunning bit of flying!

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I went out to the Fremont Weir National Wildlife Refuge this morning and spent a lovely few hours before the heat of the day began to sink in.  Saw lots of great birds including, but not limited to, Western Kingbirds that are still paired up even though most have finished breeding, Blue Grosbeaks singing all over the place, a hatch-year Red-shouldered Hawk that flew right in front of me, and an adult Red-tailed Hawk being harassed by a Red-winged Blackbird.  Among all these bird sightings I did have one really notable mammal sighting.  I was poking around through the underbrush near the edge of a small water way that runs through the refuge and came across a number of small trees that displayed the clear tooth marks of having been chewed through by a Beaver.  A few steps farther, and I saw the Beaver itself standing on the far bank at the waters’ edge.  It was eating some greenery, and when it was finished it walked up the bank, picked another plant, brought it down to the water and swam in pulling the plant in with it.  It only swam for a few seconds before it turned around, came back to shore, and began munching on the, now wet, plant.  I have no idea why it did this rinsing behavior, but it was interesting to see!  After it finished its’ breakfast, the Beaver returned to the water and swam off down the channel.  It really was a very nice morning indeed.

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