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Borneo orangs fish for their dinner
By Bruce Bower
Orangutans swim just
about as well as they fly,
but research on three
Indonesian islands shows
that these long-limbed
apes nonetheless catch and
eat fish.
Orangutans living in Borneo scavenge fish that wash
up along the shore and
scoop catfish out of small
ponds for fresh meals, Anne
Russon of York University
in Toronto reported on April
14. Over two years, Russon
saw several animals on parts
of the forested island learn on their own
to jab at catfish with sticks, so that the
panicked prey would flop out of ponds
and into a red ape’s waiting hands.
“If orangutans can do this, then
early hominids could
also have practiced
tool-assisted fishing,”
Russon said.
orangutans in Borneo sup-
plement their diets with
catfish that they snatch
out of shallow ponds.
brain growth. Good archaeological evidence of fish-eating goes back no further
than about 2 million years in members of
the Homo genus, which includes modern
humans.
Russon and her colleagues monitored
daily behavior among orangutans in
Borneo from 2004 to 2006. In 2007, the
researchers stocked a small pond with
catfish and videotaped orangutan visits
to the pond over the course of one day.
Seventeen times orangutans scavenged for fish or grabbed fish out of
ponds— several times from the prestocked pond—and immediately ate
their prey. Apes used sticks to jab at
catfish in the prestocked pond and in
other ponds as well.
Orangutans’ determined fishing
efforts underscore the nutritional importance of aquatic foods for apes in general,
not just people, Russon said. Individual
orangutans in Borneo may have discovered by accident that they could grab
fish along the shore and in ponds. These
animals then adapted sticks to the task of
catching elusive pond catfish.
Debate anew on
long-dead bones
Ancient species may have
initiated rise of Homo genus
By Bruce Bower
Fossils described last year as representatives of an ancient species crucial to
human evolution have reentered the scientific spotlight and set off a new round
of debate over the find’s true identity.
Researchers described analyses of
new and previously recovered remains
of a South African species, called
Australopithecus sediba, on April 16.
Evidence is accumulating, the scientists
reported, that 2-million-year-old
A. sediba formed an evolutionary connection bet ween relatively apelike members
of Australopithecus and the Homo genus,
which includes living people.
It’s now clear that A. sediba shares more
features with early Homo specimens than
any other known Australopithecus spe-
cies does, said Darryl de Ruiter of Texas
A&M University in College Station. “We
think A. sediba is a possible candidate
ancestor for the genus Homo.”
De Ruiter suspects that an isolated
population of the hominid species Aus-
tralopithecus africanus gradually evolved
into A . sediba, resulting in a species char-
acterized by an unusual mix of skeletal
traits, some typical of Australopithecus in
general and others of early Homo.
That scenario, outlined in symposium presentations by De Ruiter and
Lee Berger of the University of the
Witwatersrand in Johannesburg, South
Africa, remains controversial despite
new fossil discoveries.
The new A. sediba fossils, many belonging to the previously discovered partial
skeletons, underscore this ancient species’ mosaic anatomy, Berger said. A
largely complete female pelvis displays
relatively straight, vertically aligned hips
and an elongated birth canal, much like
early Homo species. Other
Australopithecus females possessed a relatively short,
wide pelvic opening and flaring hip bones.
New A. sediba foot bones include a
chimplike heel and a humanlike ankle,
Berger said. Fossils from the shoulders,
rib cage and spine, as well as surprisingly
long arm bones, typify Australopithecus.
Ian Tattersall of the American
Museum of Natural History in New
York City endorsed A. sediba as a distinct species, probably closely related
to A. africanus. “I wouldn’t classify it
as the root of the Homo genus, though,”
he said.
INDRAYANA
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