1st egg at Great Spirit Bluff!

Falcon Nova at Great Spirit Bluff just laid her first egg of the season at 8:19 AM CDT! She will most likely lay two to three more, spaced roughly two days apart. Full incubation will begin after the third egg, although we may sometimes see she or Newman spend time on the eggs prior to that. Congratulations to both of them!

We often get asked why falcons don’t start incubation right away. Won’t their eggs die? It isn’t likely. Between 80.6°/28.4° F (27°C/-2°C), eggs suspend development. Freshly laid eggs can spend a lot of time at this temperature with no harm to the egg or embryo. Nova and Newman will sometimes sit the eggs during extremely cold weather, possibly to keep them from freezing. Having the entire clutch at roughly the same stage of development reduces age/size-based sibling aggression and makes everyone a little easier to feed. Eight day old siblings aren’t trampling new hatchlings on their way to food, sex-based size differences are minimized early in development, and parents can dole out roughly the same sized bites to all of their young. This blog is about eagles, but the egg information still applies: https://www.raptorresource.org/2019/02/20/eggs-and-cold-weather/

Brand new watchers also wonder about the nesting situation. Why are they nesting in gravel? Birds nest in an incredible variety of ways! Falcons almost always create scrapes, or shallow depressions, in sand, gravel, dirt, or other detritus – although they have been recorded laying eggs in bald eagle nests in the western United States. We have more on nests here: https://www.raptorresource.org/2019/10/29/birds-and-nest-building/ and a blog about tree-nesting peregrine falcons here: https://raptorresource.blogspot.com/2017/05/a-peregrine-falcon-at-decorah-north-nest.html.