Sharks Use Math To Hunt
by Alexandra Witze
Synopsis and resource annotations by Max Grinnell
How do sharks hunt for and find their prey? Marine scientists and others have
developed many theories on how this process works, and the question continues to
receive a large amount of attention. This compelling article by Alexandra Witze
from the July 3rd, 2010 edition of Science News examines new research on how
sharks might use mathematical strategies to find their next meal.
The piece begins by discussing a new study that appeared in June 2010 in the
magazine Nature. The study noted that sharks and other marine predators
could be following "strict mathematical strategies" while making their way
through the ocean. The suggested pattern that they follow is known as a Lévy
walk. This unusual "walk" involves animals taking long forays in a particular
direction and these forays have a distinct resemblance to different types of
fractals when taken as a whole.
Most biologists once believed that animal foraging was dominated by random
motion, however in 1996 a team of researchers observed that albatrosses made an
occasional long flight that seemed distinctly like the Lévy walk. After
this observation, biologists began to notice other animals engaging in the
Lévy walk, including deer and bumblebees. After sometime, the original
study from 1996 came under attack in the scientific community, and it was
debunked as inherently flawed.
This new study by David Sims, a researcher at the Marine Biological Association
of the United Kingdom in Plymouth, states that he and his colleagues have found
the Lévy patterns and behaviors in at least 14 species, including marlin,
tuna, and sharks. Currently, Sims and his colleagues are seeking additional
evidence of Lévy behavior in lower marine animals such as octopuses. It
remains interesting work, and it will be exciting to see how it advances in the
Found below is a list of useful resources that will illuminate and
enhance understanding of the topics found within this article.
The first link
take users to an informational website created by the Monterey Bay Aquarium.
Focused on the world of the shark, the site includes instructional resources,
videos, and information on different species of shark.
The second link
take users to the Center for Ocean Sciences Education Excellence site, which
provides a plethora of information on marine life.
The third link
users away to a fascinating site created by Paul Bourke of the University of
Western Australia, which presents some basic information on fractals.
The fourth link
interested parties to a very fun and interesting Flash-based fractal maker,
courtesy of Daniel Gries and the Mathematical Association of America.
Moving on, the fifth
leads to the Animal Diversity website, which features a database of
species organized by common or scientific name. Each entry features additional
information, including natural history, habitat details, and photographs.
Finally, the last
leads to a beautiful website from National Geographic which explores
the complex world on animal migrations, with a focus on army ants, an African
elephants, the red crab, and of course, sharks.
The University of Michigan Museum of Zoology provides the searchable
Animal Diversity Web database, with species accounts (images and
text) of some of the world's mammals, birds, amphibians, reptiles,
sharks, bony fishes, mollusks, arthropods and echinoderms. The
database is searchable by common or scientific name. For each
species account, information includes scientific and common name,
classification (Phylum through Genus), and color photographs (many
beauties). Some accounts supply additional information, such as
geographic range, physical characteristics, natural history (food
habits, reproduction, behavior, conservation, and habitat), other
comments, and references. Although the list of species is by no
means complete, these simple but effective accounts are interesting
to read and will be helpful as supplemental resources in a biology,
ecology, or statistics course.