Sunday, January 6, 2013

Eagle siblings

A juvenile male, about a year old, observes duck action on the lagoon below
Last summer one of my friends asked how I could possibly know that the eagles I saw in the Nisqually delta were "my eagles," the eagle family I've been observing and photographing for several months. A strong hunch based on observation and what I've learned about bald eagles.

Many raptors set invisible boundaries around their nesting areas. Bald eagles generally don't allow other bald eagles within a mile radius of their nests before the kids fledge. When I spotted two adults hunting down on the delta, they were almost directly below the nest area. Mama eagle snagged a fish and flew up to the ridge, where I've observed them numerous times traveling back to the nest, only from the ridge viewpoint.

Sister eagle (on left) takes over a prime spot her brother was in a couple of seconds before.
So how do I know that two juvenile bald eagles I photographed at Nisqually National Wildlife Refuge are the kids of "my eagles?" A strong hunch based on observation and what I've learned about this bald eagle clan. There are two active nests on the DuPont side of the Nisqually delta. I've seen and photographed the Red Salmon Creek eagle clan on a few occasions. In late summer, I see them in the southeast sky practicing eagle maneuvers on the thermals along the ridge. Sometimes there are several juveniles, soaring, dipping, flying in formation, and practicing the courting sky dance, where they link talons and spin in the air.

Sister eagle takes over the prime spot while her brother heads for another area.
These two are young, not more than a year old. I observed them a couple of times in the past week. I saw some similar behavior that I saw when they had just started flying but were still being fed by mom and dad at the nest. They were as big as their parents, actually a bit bigger...Ma Nature gives young eagles "training wheel" wings that are slightly longer than adult eagles. Mama or Papa would drop off food, then get out of the way. These two often engaged in a food fight (link to a blog entry from July). One would steal a chunk of food and fly off to another tree.

The two at the Nisqually refuge are about the right age and are male and female. Later that afternoon, brother eagle displaced his sister in another tree above the Nisqually River. She flew off to a snag in the center of the marsh. A growing collection of favorite images from the past year can be found in my Fauna collection.

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