Reader Bruce sends photos and information about a local pair of red-shouldered hawks (Buteo lineatus):
For the past few years a pair of red-shouldered hawks has bred somewhere close to my house in Santa Cruz California (I live on campus) but I have not been able to find their nest. This species has a strange disjunct geographic distribution— a population in eastern North America, a population in California and Baja California, and a vast area in central North America where they are absent. These hawks are gorgeous, as this photo of the male shows; the western population is distinctive and particularly colorful.
Last summer the pair parked their two fledglings for a few weeks in trees very close to my house. One of the fledglings decided that its favorite perch was a branch a couple of feet from a neighbor’s bird feeder. Fortunately for the local birds visiting the feeder, red-shouldered hawks in our area eat mostly herps [reptiles] and some mammals (pocket gophers). The chick was also a complete klutz as a hunter and we watched it try and fail to catch earthworms on our lawn.
While the chicks lounged, the two parents hunted farther afield for food which they brought back to the chicks periodically. This chick got an alligator lizard and the photo shows the bird just about to polish off the lizards head.
This one got a snake from a parent and this photo shows the tail end of the meal.
Cheeky fledgling sitting in a tree ten feet from our back door.
Here’s their curiously disjunct distribution, taken from the Cornell Ornithological Lab site (link above). The purple marks their year-round habitats.
You say that they do not eat birds but surely other birds will not distinguish between different raptors, will they? Was there no mobbing behaviour?
Lovely plumage!
Another question for Bruce – are there pellets of regurgitated bones under the perch? That would be interesting to see what they eat from the remains – I know it is what you do with owls when you wish to know their prey.
Do hawks ‘hork’ up the bones and fur?
Hawks can digest bone. Their casts contain fur but very little bone.
Nice photos! I’ve seen red shoulder hawks here sometimes in the summer but they are hard to tell a part from red-tails when flying.
Very nice.
Nice photos, thanks!
Good work, Bruce!
When you see them eating their relatives it is important to check that they aren’t also inflicted with christianity.
Ornithrophagy – I’m going to use this all the time thanks to gravelinspector-Aidan
Are there any genetic studies of the disjunct populations?, he asked, and then googled his own question. Why, yes there are:
http://www.sciencedirect.com/science/article/pii/S1055790308004582
There is said to be a fairly deep divergence between eastern and western populations, though mitochondrial control region haplotypes differ by only one or two substitutions.
Hi John
Thanks for digging that up. I will give it a read.
From John’s linked article:
“We found evidence of differing demographic histories between regions; among eastern sites, mitochondrial data suggested that rapid population expansion occurred following the end of the last glacial maximum,”
Aha, as soon as I saw that map my first thought was whether this was evidence of past glaciation in North America. Very cool!
Wonderful photos!
The light in Santa Cruz is really quite special, and you’ve done a very good job, Bruce, of capturing it as reflected in these birds.
b&
Perhaps it’s the fog? If the fog is thin enough, the lighting almost becomes studio-like (in a good way).
I’m sure the atmospheric conditions are a crucial element, but it’s also going to have something to do with the color of the landscape. The quality of the light in a room painted red is going to be much different from that in a room painted green, and the quality of the light in a checkerboard-painted room is going to be different yet again….
b&
After Thanksgiving, the stripped turkey carcass is taken to just inside the wood line in my back yard. It never stays for more than a day.
With last year’s offering, the first scavenger to come by happened to be a red-shouldered hawk, so they do at least eat birds that are in no position to complain. I’d link to a picture of the event, but the quality is truly shameful compared to those above.
Beautiful photos. Thanks Bruce!
Wonderful shots, and I especially like that you’ve captured them going about their business. Also, don’t think I’ve yet seen a Red-shouldered with quite so red a shoulder! Wonder if that trait varies between east and west populations as well?
Such a fantastic opportunity to witness these family dynamics at such close range and over time.