Ospreys -- March, 2016 - John Longstreth Nature Photography

The season is changing. I enjoy all the seasons in Inverness, but early spring is special. The days are longer, the first trees are blooming and the strong north-west winds haven't started in earnest. Life on Tomales Bay is changing too: there are fewer herring runs and some of the ducks heading north for nesting.

In March, we see the influx of one of my favorite birds, the osprey. Ospreys are large black and white fish hawks. We see them diving talons first into the water and coming up seconds later, usually with a large fish. In the first few seconds of flight, it maneuvers its prey to a head-first position, making the load more aerodynamic.

There have been a few alpha osprey males hanging around all winter, making an early claim to the prime nesting sites. But now many more will be migrating into our area. A couple of years ago, Tom Gaman and I counted at least 30 osprey nests on Inverness Ridge from the Yacht Club north to Heart's Desire. Anyone who walks on the roads and trails on the ridge in spring and summer will hear their shrill, repeated yoop-yee-oop calls, particularly when the hungry nestlings are begging.

Ospreys have made a remarkable recovery from the DDT days. Being a top level predator, the poison accumulated all up the food chain from the plankton through the fish to the hawks' tissue. As with so many other hunting birds like pelicans, peregrine falcons, and bald eagles, DDT affected their reproductive hormones, thinning their egg shells to the point where successful hatching rates approached zero.

The bald eagle is the osprey's major competitor. During much of the year, one can see eagles perching on one of the posts of the ancient bat-ray fence at the mouth of Papermill Creek. Another fish-hunting raptor, the bald eagle is also a scavenger and a thief, being more than happy to dive-bomb a fish-carrying osprey, forcing it drop its meal which the eagle then scoops up.

Ah, nature red in tooth and claw.

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