OCTOBER 20, 2011:
A friend of mine who lives in Lakeway reports that there are loads of robins at her feeder. What’s up? We usually see 1 or 2 in the early spring.
Thank you for your question to Travis Audubon about American Robins in Austin. What’s up is right! I’ve included a picture of an abundance graph at the bottom of this email that I generated using Cornell’s eBird online tool. It shows that American Robin abundance usually peaks in December, with a smaller spike in November. I don’t generally expect to see flocks of them in October!
While I’ve been out birding this summer and early fall, I have seen more robins than I usually do – usually one or two on each outing. We always have a small population of resident birds who are with us year-round, but it seems like they are increasing in numbers overall.
When we see an unusual number of wintering birds or see them earlier than usual, we call that an “irruptive” year for them. Last year we was an irruptive year for Golden-crowned Kinglets, for instance. The year before it was Pine Siskins. It looks like the fruit and berry crop north of us must be sub-optimal, and the robins are ranging farther south earlier than usual in search of their preferred winter food. Presence or absence of food is the usual reason for unusual dispersal of wintering birds.
It’s interesting to note that robins cannot digest hard fruits or grains. They will take insects such as mealworms at a backyard feeding station or soft fruits like berries. You can also find them enjoying the fruits on an American Beautyberry if you have one in your yard. While the ground is still soft and wet, they may also forage on the ground for their year-round source of protein, earthworms.
It will be interesting to see what else pops up different than usual in our area this year. Thanks so much for reporting your friend’s flock of robins!