Each spring since 2011 I have observed an osprey (Pandion haliaetus) nest near Crystal Lake (Shasta County CA). This large nest sits about 50 feet off the ground atop a ponderosa pine snag. In 2015 I was surprised to discover a pair of Canada geese (Branta canadensis) occupying the osprey nest. That year the Canada geese successfully got three of four goslings into the water (one gosling died jumping from the nest) after which the osprey also had a successful brood. Last year (2016) the geese and osprey again both had successful broods in the same nest.
Last week I checked the osprey nest again and found Canada geese using the nest. Pairs of Canada geese often return to the same nesting site in consecutive years. I wonder if this is the third year with the same pair in the osprey nest?
Canada geese mate for life. The female selects the site and does most of the nest construction. The nest is usually placed on the ground in a slightly elevated spot that provides an unobstructed view in all directions. This lone snag rising well above the surrounding vegetation meets that requirement. The Canada goose nest is a cup of dry grasses, lichen, mosses or other plant material lined with down and some body feathers. The osprey nest provides a large “cup” of branches and twigs which the Canada goose female lines to her satisfaction. After the goose eggs hatch and the goslings leave the nest I find large amounts of plant material and down that the osprey toss out of the nest as they refurbish the nest to their own specifications.
The female Canada goose incubates the eggs while the male stands guard nearby. At first I saw the female alone in the nest. I searched the area for a male but could not see him. After about 15 minutes the male came flying from the lake. The pair appeared to greet each other with stretched necks and honking after which the male stood on the edge of the nest while the female continued to tend and sit on the eggs. I left the pair alone after another 15 minutes and will check on them again soon.
I hope this osprey nest will again serve two different species again this year.