Robin
Nest Cam Lesson #3: Growing Babies!
As
you watch the video clips, think about these things:
- In the
first clip, the father came in with the food. Which parent deals with
the baby droppings in this one?
- In the
second clip, two of the babies are preening. Do you think it's hard
for the third baby to nap while the other two are grooming themselves?
- In the
third clip, the father has just fed the babies, and one of the babies
poops. What does the father do with the fecal sac? Do the babies notice
when he flies away? Do you think that watching him fly makes them think
about the days when they, too, will be able to fly?
- In the
fourth clip, two of the babies appear to be sound asleep and the other
is sitting quietly when suddenly the father flies in and they all pop
up. It looks like they pop up a split second before he actually lands
on the nest. How do you think they knew he was coming? Adults feed the
baby or babies that appear to be the hungriest when they return. Do
you think being very fast about this makes it more likely that they
will get some food?
- In the
fifth clip, it's clear the nest is getting crowded. The baby who is
preening is perched on the edge of the nest part of the time. Notice
how big his or her feet are! The feet and legs of a robin reach adult
size before the rest of the baby does, giving the baby a clumsy appearance.
Do you think the big toes help it to preen?
- Adult
robins are supposed to only eat their babies fecal sacs when the babies
are very tiny, but this mother robin is not paying attention to that
rule in the first clip! To learn more about how the parents deal with
baby bird poop, see our lesson The
Scoop on Poop: Disposable Diapers for Birds. Think of at least three
advantages of parent birds eating fecal sacs of very young babies. Why
do you think they usually stop eating them after the babies get older?
After viewing the videos, discuss these questions with your
classmates or in your journal! Discussion will appear in Robin
Nest Cam Lesson #4
Discussion
of Questions from Lesson #2
"Do
you think most robins bounce their babies a little when they fly off the
nest? Can this hurt the eggs or nestlings?"
Most
robins actually bounce their babies MORE than these robins do, because most
robin nests are on branches of trees, which bounce a lot more than a ladder
does! This has been happening for so many thousands of years that baby robins
are designed to live with it.
"What is the mother feeding these tiny nestling?"
The
mother is regurgitating
small
bits of the food she has caught and eaten herself. They are so tiny that
a whole worm would be too big for their mouths and throats, and their stomachs
aren't ready to digest raw food yet. So her stomach gets the process started.
This is also how their stomach and intestines will get the right bacteria
in them so as they get bigger they can feed themselves and digest all their
own meals.
"What is the mother eating in the second and third video clips?"
The
mother is eating the babies' fecal sacs--their poop! The babies are so tiny
that they aren't digesting all their food, and their intestines don't have
much bacteria yet, so this helps the mother to have enough food while she's
spending most of her energy getting food for the babies. To learn more see:
The Scoop on Poop: Disposable
Diapers for Birds.
"Why does the female open her beak when the male flies in?"
The
female is a little stressed when ANYTHING approaches the nest when the babies
are so tiny. So her open beak may show a little fear and a little warning.
But it also helps her to beg from him. Her hormones are all geared up to
nurture babies. If the male feeds her, she can use that food to feed the
babies.
"What food is the male bringing?"
It's
hard to see it for sure. He has definitely swallowed worms and or bugs,
because he has to wiggle his throat to make them come up again. It looks
like he may have given her a small worm or just the stringy, goopy remains
of the food he's eaten. "Why
doesn't the male feed the babies?"
The
male is perfectly capable of feeding them. But at this point, the mother's
hormones are at such a high level that she is more protective of and anxious
to feed the babies than he is, so she is the one who does that job.
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