
American Robin (Turdus migratorius)
The four American Robin chicks in this nest had grown large enough at this point that they hardly fit in the nest together. (For scale, the interior portion of a robin’s nest is approximately the same size as a baseball.) For the entire time I was in their immediate vicinity, they didn’t move or make a sound. In fact, they hardly blinked. I can only assume both parents were out foraging at the time I encountered the nest, because although American Robins are known to aggressively defend their nests, I didn’t notice any adult robins, let alone any producing alarm calls or trying to dive-bomb me.
According to All About Birds, American Robins can successfully produce 3 broods in a single year, but only about 40% of nests produce fledglings. Given that the four chicks in this nest all seemed healthy, it seems like this nest will at least produce successful fledglings. American Robin chicks tend to fledge about 2 weeks after hatching, which based on their size, will be soon. However, records show that only about a quarter of those that do fledge will survive to November. This somewhat low survival rate may account for American Robins’ inclination to lay multiple broods in a season.
Have you noticed any birds’ nests this year?