"Why do you think
that Robins virtually never build their first nest of the year in an oak
or maple?"
Robins
usually arrive on their breeding grounds a few weeks before deciduous
trees such as maples and oaks leaf out. To protect the incubating female
and the eggs and nestlings from wind, rain, and even too much sun, they
select nesting trees that provide better shelter.
"Can
you list some ways that weather affects robin nest construction?"
Robins require thick mud for their nests. If the weather has
been too dry, mud won't be available. If the weather is cold (especially
in spring) the top layer of ground can freeze, making mud hard to chip
out. If the weather is too rainy, the mud might be too runny for the robin
to hold in her beak, and steady rain over a nest-site can dissolve the
mud as the nest is being constructed.
"What
three things do these two newly hatched baby robins already know how to
do?"
They know how to:
- Sit very still when their parents are away
- Pop up and open their mouths to beg for food the moment their parents return
- Poop as soon as they swallow some food.
"How can the nest and other babies stay clean
when one baby robin poops?"
Healthy nestlings produce poop that is encased in a fecal sac, that works
like a disposable diaper bag and keeps all the poop inside! To learn more,
look at Journey North's Fecal
Sac Lesson.
"What
is a reason why most birds don't grow feathers over their whole bodies
but only in tracts?"
Except for a very few birds like penguins,
who swim in VERY cold water, most birds don't need to grow feathers over
their whole bodies. One individual feather is a lot wider than one hair,
and can cover a bigger space on a bird's body than one individual hair
can cover on a mammal's body. But feathers take a lot of energy to produce.
To save energy, birds produce just enough outer feathers to completely
cover their bodies when the feathers are groomed properly. These robins
will each have about 2200 to 2600 feathers when full grown, and add more
in the fall for winter insulation.
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