Biology Reference
In-Depth Information
CHAPTER
5
Actions Speak Louder in Birds: Bird Behavior
Birds are fascinating! Whether we're watching cardinals nesting in a shrub near our
window, a Red-winged Blackbird chasing a huge Red-tailed Hawk in the sky, or a
pair of dancing Western Grebes scooting across a lake on our TV screen, we can't
help but marvel at the ways they go about their daily lives. Current research is es-
tablishing that birds are more intelligent than people once believed. Studies are also
showing that birds such as chickadees and canaries replace brain neurons every year,
allowing them to delete outdated memories and create new ones so their relatively
small brain can keep up with their changing world. The more we learn, the more
amazing birds prove to be.
How to Think Like a Bird
Q How big are bird brains?
A
Bird brains are 6 to 11 times larger than those of similarly sized reptiles — comparable
to mammalian brains as a percentage of body mass. Because bird brains are somewhat
similar in structure to reptilian ones, scientists have long labeled the structures using the
same terminology as for reptile brains. But in 2005, a consortium of neuroscientists pro-
posed renaming bird brain structures to portray birds as more comparable to mammals in
their cognitive ability. The scientists asserted that the century-old traditional nomenclature
is outdated and does not reflect new studies that reveal the brainpower of birds.
Q I read in a newspaper column that hummingbirds remember the people who feed
them. Is this possible?
A
Alexander Skutch, who spent many decades studying birds in Costa Rica, wrote in his
book
The Life of the Hummingbird
that after years of observation, he was convinced that
they do remember. When a hummingbird comes to your window in spring and looks in as
if expecting you to feed it, it's easy to jump to the conclusion that the bird is the same one
you fed the previous summer, and it probably is. But we can't be absolutely certain about
that without marking the bird in some way.
It's harder to systematically study hummingbirds than larger species; only a handful of
people are licensed to band hummingbirds, and the birds are so tiny that leg bands aren't
easy to read without recapturing the birds. Color-marking hummingbird feathers may af-
fect how other birds respond to them, disrupting their normal social interactions and be-
