A swoop of osprey

Before last night, there was no need for a collective noun describing a group of osprey. They tend to fly and hunt alone. But conditions must have been perfect yesterday evening, the rain gone, the sun setting, the breeze dying, the water surface of the cove smooth and transparent, the fish schooling at the surface. All through dinner, and well beyond, Cindy and I heard them chirping like mad, and watched them soar and dive, sometimes swooping up at the last second, sometimes hitting the water with a tremendous splash and emerging with a mackerel. Cindy says there were eight. I don't know - I was innumerate.