City Animals Have More Street Smarts
Scientists Find Urban Mammals Have Bigger Brains
by Sydnee Griffin, age 16
For years, humans have been changing animal
habitats. New research suggests that we could also be changing the size of
By chopping down trees,
building more apartments and paving new roads, humans have been carving up the
rural area these animals inhabit. This has resulted in naturally urban
creatures having brains six percent larger than rural creatures.
of Minnesota biologist Emilie C. Snell-Rood conducted an experiment involving
century-old skulls from ten mammals housed in the University’s Bell Museum of
Natural History. Undergrad Naomi Wick used the dimension of each skull to
estimate the size of the animal’s brain. Her data show that the brains of the
mammals in cities were larger than those of their counterparts in rural areas.
Dr. Snell-Rood believes this
is a result of humans changing the landscapes. Forests and prairies yielded to
cities, displacing these mammals, influencing survival capabilities of these
animals. Lack of forests and other rural areas force animals to scavenge
farther and farther away from their homes. This can be a dangerous and
demanding task for small-brained animals.
also took note that larger-brained animals were not only more capable of
learning, but were more likely to stay alive and reproduce.
by other scientists support the connection between bigger brains and better
learning. Researchers at the University of Sweden Uppsala performed an
experiment using guppies bred for larger brains. Scientists found that the
large-brained guppies scored higher on learning tests than the small-brained
Snell-Rood’s hypothesis on the larger animal brain is still quite new. Others
in the field recognize that Snell-Rood’s ideas need to be tested in more ways
to rule out other explanations for the change in brain size. If Snell-Rood’s
idea is proven true, museum skull collections all over the world could serve as
the constant variable in further research. With continued research, we might
one day be able to more precisely measure human influence on animal
[Source: The New York Times]