Re: Patterson Pass Hawks (Not) and other birds….

Alexander Henry

These are some interesting observations! I had personally noticed Ferruginous Hawk numbers in eastern Alameda county seem to be lower this year than last year, but I was wondering if that was just me.

That’s a lot of shrikes. I often check them for Northern Shrikes, but maybe I’m just day dreaming - that seems pretty unlikely (but perhaps possible?).

On Monday, February 1, 2021, Jim Chiropolos <jnc@...> wrote:
Since my days doing tallgrass prairie restoration and breeding bird surveys in Illinois a long time ago, I have always enjoyed grasslands. In the bay area, the best grasslands are off Patterson Pass and it’s one of my favorite birding and biking routes. Yesterday I biked up Patterson pass from the Cedar Mountain Winery to the county line where development starts in San Joaquim county and back, my standard route.

I was amazed at how few hawks there were. I only saw ONE!!! Red-tailed hawk off Patterson pass road!!. In past years doing the route and bailing due to heavy fog at the pass have seen more redtail-hawks with visibility of 40 feet in fog and visibility yesterday was great with the Sierras in view from the pass. Past checklists for this time when I have biked with good visibility I have counts of 20 or red-tails along the route!!! I think this shows how severely the drought is affecting the prey species of redtails and large raptors (no harriers either). I only saw two 2 TVs, one Golden Eagle and a beautiful rusty Ferruginous Hawk to complete the large raptor count! Astonishing low numbers. It’s a good thing birds have wings as the hawks must be somewhere else to find food. I have suspected all year that it is a very low number of raptors this winter and this is a good example.

I was surprised to see a good number of Loggerhead Shrikes however. I saw at least nine, with what appeared to be four pairs and saw one territorial battle between two pairs of shrikes (the high count for Patterson Pass in eBird is 11). They were quite loud with their fascinating buzzing calls. Their food source must not be as severely impacted as the hawks.

The highlight of the day was a group of 1,000 to 2,000 blackbirds on a cottonwood next to the road near the power plant. Most were trikes (Tri-colored Blackbirds), with some red-shouldered blackbirds. Trikes, a California endemic with plummeting population numbers, are colonial nesters and forage in very tight groups. Watching trike is fascinating, like watching a colony of nesting seabirds as they feed. They put out a lot of noise, and the din from the flock was quite impressive.

At the winery, mountain bluebirds were present as usual. I think I missed the big flock, which were flying away just as I arrived at 10:15.

And I have one more thing for the listers out there. A Cassin’s Kingbird is at the intersection of Tesla and Cross roads on fenceposts and wires – this is a good spot for them as I have seen them here in the past. I am now seeing Cassin’s on a regular basis in the winter in the greater Livermore area over the last two years. Only six or seven years back, a Cassin’s Kingbird would draw large numbers of county listers when found in Alameda county but now to a lister, it’s just another bird. I’m going to predict in the next year or two, a chaseable Cassin’s will be found in Contra Costa county several miles north, as I think they are moving their range north. Its funny, that bird will draw hoards of listers while the same species several miles would be considered not worth watching. What a beautiful bird they are, especially in the winter.

Good birding

Jim Chiropolos

Alex Henry

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