Geoscience Reference
In-Depth Information
Egyptian vultures (
Neophron percnopterus
) of Africa, bristle-thighed curlews (
Nu-
menius tahitiensis
) of a few Pacific islands, the palm cockatoo (
Probosciger ater-
rimus
) of Australia, brown-headed nuthatches (
Sitta pusilla
) and burrowing owls
of North America, and various herons, egrets, and seagulls. Of these birds, New
Caledonian crows are the most impressive of tool users and problem solvers. These
crows carefully choose or shape sticks, leaves, or feathers into practical objects,
which they use to acquire food. In laboratory settings, they have even used metal
hooksprovidedbyresearchers,andsometimesbenttheseintousableshapes.Wood-
pecker finches latch on to cactus spines or twigs with their beaks and then manip-
ulate these like fine surgical tools to extract insect larvae from tight spots in trees.
LikeNewCaledoniancrows,theyalsomaymodifytheseitems—suchasshortening
them—to improve their utility. Egyptian vultures and bristle-thighed curlews share
the practice of grabbing a rock with their beaks and throwing these at eggs to break
them open. These vultures do this to ostrich eggs, whereas the curlews crack al-
batrosseggs;intriguingly,thevulturesseemtopickrocksthatareegg-shaped.Male
palm cockatoos grasp sticks in their beaks, which they then drum against trees to
alert females that they are in the area, echoing the mating habits of beat poets who
used bongos in 1950s coffeehouses. Brown-headed nuthatches acquire short pieces
of bark or sticks, which they lever against the bark on tree trunks to expose insects.
Perhaps my favorite tool-using bird, though, is the burrowing owl. These actually
use mammal feces as a tool, by picking up pieces of bison or cattle dung, placing
these in front of their burrows, and waiting for dung beetles to arrive, which they
then happily devour. Lastly, a few species of herons, egrets, and seagulls go fishing
by employing feathers, berries, and even bread as lures. They either dangle these
items from their beaks above a water surface or drop them onto the water to attract
fish, which they then nab.
So do birds have memes—culturally acquired behaviors that modify over
time—as well as genes? Although acquired knowledge and tool use is certainly
sharedamongcontemporarypeersandwithoffspringinsomebirds,behavioralbio-
