Friday, August 10, 2012

California (raptor) dreamin'....

     In February the Bear Valley, like many other parts of California, is green with spring.  Farms, orchards, and vineyards carpet the valley floor.  Bordered on the west by the Gavilan Mountains and on the east by the southern Diablo Range, the valley is a visible manifestation of the San Andreas fault.  A quiet two-lane highway runs the western length of this striking landscape, a road enough off the beaten path that one can pull off to the side without fear of causing a traffic catastrophe.  And that's a boon to birders, especially hawk gawkers.

     It was one gorgeous late February day that we ventured southward from Hollister along the verdant fields and hillsides. The valley must be home to uncountable small furry critters and lizards and other tasty fare because we saw raptors almost everywhere.  A wide range of behaviors were exhibited: many were hunting, some of the birds were in dramatic courtship displays, some were engaged in what appeared to be territorial disputes, some were migrating, and some were possibly hangers-on from winter, not quite ready to head north.  
photo by S. Fogleman

     Red-tailed Hawks predominated, providing great opportunities to study a wide range of color variation.  I believe I have come to love the dark Western morph the most.  American Kestrels seemed to be everywhere, and I think I can truthfully state that I have never seen so many in one day anywhere other than a coastal migration watchsite.  They hover-hunted over fields, they were perched on utility lines, on fence posts, on small saplings.  They pestered Red-tails, they pulled the wings off large insects, they preened, they mated, and made us wonder if this was the Kestrel Shangri-la.

     Northern Harriers were probably the next most numerous, with silvery adult males as well as "brown" birds drifting back and forth above the grasses and marshy areas, and sometimes sitting on a fence. Red-shouldered Hawks were often perched on utility poles along the road.  We spotted the occasional Merlin zipping along parallel to the road, or perched on a snag on the steep slopes on our west side.  Here and there a delicate-looking White-tailed Kite captured our attention. Sharp-shinned and Cooper's Hawks were frequently spotted.  A side trip up into Pinnacles National Monument rewarded us with awesome albeit too-fast-to-get-the-camera views as a Prairie Falcon whipped over us at about 30 feet.

     When the frequency of Golden Eagle sightings equals what you might have of Red-tails in the East, you know you're in great raptor country.  Two Goldens acting a bit "courtship-ish" caught our attention as we scanned a horse pasture below us.  At another stop one appeared to be mantling over prey .  Sometimes, while watching a pair of Red-tails in the sky, a Golden would drift into view.  Then there'd be one that was perched on a rocky outcropping, or the archway of a ranch entrance.  At overlook pull-offs where we would be looking down on these birds, their golden nuchal feathering gleamed in the afternoon sunshine.

     Best of all to this Easterner, were the Ferruginous Hawks.  I spotted the first one when we were still about 400 meters north of it as it perched on a fence post.  It was definitely a "wow" moment for me, but the next three or four sightings of that species were just as "wow," as each of those long-winged buteos made certain we appreciated their majesty.
Ferruginous Hawk - photo by W. Fogleman

     Had we visited a week later would we have seen as many raptors?  Would we have seen as much diversity(12 species, including the abundant Turkey Vultures)?  What might it have been like a month earlier in that valley?  Perhaps some light could be shed on the situation by systematic monitoring such as the Winter Raptor Survey.  I'd volunteer, except that I live 3000 miles away!

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