Ospreys and SoundVision

People at Tuesday's Long Island SoundVision press conference, at the Indian Harbor Yacht Club in Greenwich, were excited to see three ospreys using the harbor as a fishing ground. A few dozen of us were inside and on a porch with great views of the rainy seascape as the ospreys flew past, hovered, and then plunged into the water, sometimes emerging with a fish, sometimes not.

One of the SoundVision goals is "Creating Safe and Thriving Places for All Sound Creatures." We've managed to do that for ospreys and we did it simply by banning DDT.

Tom Baptist, the head of Audubon Connecticut, was there Tuesday and reminded me that historically there were an estimated 500 osprey nests along the Sound. When he and Joe Zeranski were researching their book, Connecticut Birds, in the 1980s, there were only five osprey nests.

He told me on Tuesday that while he has counted them lately, he thinks that now there might be more than 500. Every one is a reason for small optimism.

Greenwich Hawks

Audubon Greenwich says that more than 26,000 hawks, eagles and other raptors passed over its Quaker Ridge hawk watch this fall, which is 7,000 or 8,000 more than the last two years. On September 18 alone, they saw 13,000 broad-winged hawks. A Greenwich Time reporter named Colin Gustafson has a first-rate explanation today, here:

Several factors were at play on Sept. 18 when thousands of broad-wings suddenly began funneling through the roughly seven-mile stretch between Quaker Ridge and Long Island Sound, O'Toole said.

Like most hawks, broad-wings migrate across the ridge's southern edge to take advantage of the warm air currents, known as "thermals," that bounce off the ground and propel them to high altitudes, he said.

Once atop the thermals, the hawks can soar for miles on the tailwinds without having to expend energy by constantly flapping their wings, as lower-flying birds do, to stay aloft.

However, this advantage fades when the hawks begin flying over water, where the cooler air currents make it much harder to sustain long periods of soaring. As such, O'Toole said, hawks typically hug the shoreline when the wind pushes them close to the ocean.

On Sept. 18, after being grounded by a cold front along their migratory route for several days, the hawks began taking off in large flocks, known as "kettles," as soon as the ground started to warm up.

At the same time, a moderate northwestern wind began pushing them closer and closer to the cool waters of the Sound, creating a bottleneck of birds trying to ride out the warm thermals between the ridge and the coastline, he said.

"It was just the right combination of factors, where you had this gradual build-up of hawks" in the region waiting for the cold front to lift," O'Toole said. When the air warmed and the wind began blowing, there was "this explosion of huge numbers."

While the one-day numbers are impressive, O'Toole added, they are not unprecedented: On Sept. 15, 1995, there were 31,988 sightings of broad-winged hawks at the ridge, likely due to similar wind and weather patterns.

Regular readers may remember that we have our own (so to speak) broad-wings here, nesting at the bottom of our driveway and attacking us and others whenever we walk past in May and June. Gory details here.