On Osprey Time

Orpheus carrying a white sucker, courtesy of Cynthia Sedlacek. The elegant 100-foot dive of the Osprey displaying its remarkable athletic ability was celebrated in Blog #385. In this blog, we’ll look at the object of their efforts—fish. Ospreys are excellent anglers. Most sources claim that Ospreys can catch fish at least once in every 4 dives, with success rates sometimes as high as 70–80%. The average time they spend hunting before making a catch is about 12 minutes— something to give fishermen pause. The success rate varies throughout the breeding season and can be affected by changes in the water depth, time of day, fish availability, and weather conditions, especially the wind speed. Ospreys eat different species of fish, depending on the habitat type they forage. Studies in the US on the Osprey diet have identified at least 80 species of fish. Ospreys are opportunists and will eat whatever fish is readily available to them, with only a few species of fish dominating their diets i

A chronophotograph of an Osprey diving, courtesy of Chen Chengguang. An Osprey’s famed dive is pure artistry. Watch a majestic osprey cut through the wind, averaging 30 mph as it soars across the sky. Suddenly it will stop mid-flight at a height of 30–130 feet to hoover, slowly beating its wings to stay in one place, like a giant kingfisher or hummingbird, while peering down with eyes that can see into the shallows from a hundred feet up. Just a glint or a shadow of a movement below means one thing—a fish. Once a potential prey has been spotted the Osprey hovers briefly and quickly decides whether to dive or move on for a better opportunity. Ospreys can dive without hovering when the opportunity for a potential catch arises.  Once the Osprey commits to the dive, it tucks its folded wings and plunges on a vertical or diagonal trajectory up to 80 mph while still keeping its eyes on the prey, calculating its size and movement, and the refraction of the fish's image in the water. To ga

Ospreys typically lay eggs in the morning, so the bird is not constrained by the weight of the egg during the  daytime. Studies in New England show older females lay two weeks earlier than younger females, and pairs that previously nested together lay earlier than newly formed pairs. Early breeding is an advantage to this predominantly monogamous species, especially in areas with short breeding seasons. Early breeding pairs generally produce more young with higher survival rates.  Some of the many colors and patterns on Osprey eggs, courtesy of YouTube, flicker, and nwrafting.  Osprey eggs are considered one of the most beautiful eggs in the animal kingdom. They have a creamy  white to cinnamon-peach backgrounds and are heavily wreathed and spotted with rich red to dark brown with flecks of lavender and swirls of mahogany in an infinite number of patterns. The surface is satin   More unique Osprey eggs, courtesy of acorn naturalists, flicker, and boneclones.  rather than a glossy finis

Ursula tending her three eggs.  Life at the Salt Point nest has been anything but restful this week. It began with the laying of the first egg.  For two days before the grand event, the pair stayed very close together and mated frequently. Both birds  were “nesting” by putting the finishing touches on the softly-lined eye cup in the nest. Wads of grass are  distributed throughout the nest and then worked into the structure by the constantly fussing of the pair.  Most of this time Ursula stays low in the nest, incubating the eggs, and fiddling with the nest interior and  will brings wads of grass to dig into the egg cup. Orpheus is almost as constant at the nest guarding his  mate. The day before and the day of laying Ursula stayed low in the nest as if incubating. The actual  laying of the first egg happened fairly quickly with no outward signs of stress as it occurred. Ursula sat  down, laid the egg, and stood up, all the while staring straight ahead. After she rose, she inspected the