Puxatawney Phil saw his shadow this morning, thus forecasting 6 more weeks of winter. Most people in the USA took this as a bad sign that spring will not come early—the prediction when Phil does not see his shadow. However, we hardy Minnesotans do not mind 6 more weeks of winter whatsoever.

A sure sign of spring comes with the sighting of the first robin in my yard—typically later than Phil’s more pessimistic forecast. I looked for statistics on the annual migration of robins from the USA National Phenology Network but, though this bird is their most frequently observed animal with over 190,000 records, nothing came up readily on dates of first sightings in my region of the country.

In any case, I will be very happy if the robins do beat the 6-week forecast for spring as they did in 1996 per this report—arriving in Minneapolis on March 12^th of that year. Until then, I can only enjoy this lovely video of American robins produced by Lesley the Bird Nerd who grew up north in Ontario—the next stop in the bird’s spring migration after Minnesota.

What got me thinking so early in the year about robins was a report in the Royal Society last week on “The limits of egg recognition: testing acceptance thresholds of American robins in response to decreasingly egg-shaped objects in the nest”. Check out the bizarre fakes—robin-egg blue, of course—pictured here . Evidently it’s not the shape that matters, for example, a pointy eight-sided egg stayed in the nest, but, rather, the size. Those that looked big enough to be put in by a cowbird, a parasitic species, got tossed out. The robins also rejected eggs that were too thin.

“They seem to be quite hesitant about rejecting eggs when the variable that we changed was not natural,” Dr. Hauber said, referring to the angular, pointed eggs. “Robins don’t know what to do with it, because they’ve never evolved to respond to it.”

Quote reported by New York Times in their interview of lead-author Mark Hauber, a professor of animal behavior at the University of Illinois, Urbana-Champaign.

I am tempted to dig up the collection of Dungeons and Dragons dice left behind by my two sons after they moved out and put them out in the bird house this spring to see what happens. Just joking—I like robins too much to do anything so inhospitable. It is very weird, though, that they are so bird brained about egg shapes.