Biology Reference
In-Depth Information
ing or trying that behavior beforehand. Many innate behavior patterns are refined by
learning.
For example, when a robin first hatches, it already knows how to do three things.
If something lands with a soft thud or jostles the nest, the little bird pops up like a jack-in-
the-box with its mouth wide open to be fed.
As soon as the little bird swallows, it backs up and poops.
After it poops, it crouches down again and remains fairly motionless until the next time
the nest is disturbed.
On a visit to the nest, the parent robins feed whichever nestling begs first, extends its
neck highest, or holds its beak closest to the parent's beak. Adults usually follow one or
two flight patterns, alighting in the same spots over and over, so nestlings quickly learn,
by feeding success, where to direct their beaks. They're already refining their innate be-
havior by learning.
Learning Who's Who and What's What
Forseveraldaysafterhatching,robinnestlingsbegifanything,includingpeopleorpred-
ators, alights onthe nest orovershadows them. About five days after hatching, their eyes
open and they start noticing their parents and one another. Once they recognize the birds
that feed them, they will crouch down if anything else shows up. By the time they're 10
or11daysold,ifanythingapproachesthenestthey'llflyoffinaflurry,thoughtheycan't
go far and can't get back up to the nest. (This is why it's so important to not peek into
robin nests after the young are about a week old.) If the young survive this sudden, pan-
icky escape, their parents will continue to feed them and will try to lead them to dense
vegetation to keep them hidden.
Robins don't “imprint” on their parents or each other. For a day or two after leaving
the nest, especially if something caused them to leave the nest too soon, a hungry robin
chick who cannot find its parents may beg from other bird species or even people. I once
saw a robin fledgling begging from my golden retriever! After a robin is flying well, it
learnstofollowitsparentsandassociatewithotherrobins.Afterthat,itavoidsotherspe-
cies.
Robins have a few sharp warning calls, including a high-pitched
seeee
made when
a hawk flies overhead, and
peek
and
tut-tut
calls when danger is lower to the ground.
Young birds recognize the sounds their parents make and act on these sounds; some of
this may be innate and some refined by learning as they notice what their parents do.
Both parents attend to the young after they leave the nest. After the female produces
a new clutch, she incubates them as the father stays with the fledglings. Every night he
