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Lightweight, but
also carnivorous
By Alexandra Witze
The dinosaur family tree just added a new
relative: a small, meat-eating creature
dating back to dinosaurs’ earliest days.
Unearthed in Argentina in 230-million-
year-old rocks, the bipedal Eodromaeus,
or “dawn runner,” would have been as tall
as a 7-year-old but as light as a house cat.
Eodromaeus joins its kin Eoraptor, a
similar-sized dinosaur known to have
lived in the same time and place. In
fact, when researchers first unearthed
Eodromaeus they thought that the bones
belonged to Eoraptor. Despite the two
dinosaurs’ superficial resemblance, one
ate plants while the other ate meat.
Roughly 4 feet high, the new-
found dinosaur Eodromaeus
would have been an agile
but not fearsome hunter.
Penguins’ IDs may impair survival
Metal bands on flippers also shown to reduce reproduction
By Susan Milius
A 10-year project has found that
metal identification bands that
researchers attach to penguin
flippers can cause long-term
harm to the birds and possibly
to research results, too.
Scientists trying to tell one
tuxedoed bird from another —
no small task — in some cases
wrap metal strips with ID numbers around a part of the flipper
near the bird’s shoulder. On an
island in the southern Indian Ocean, king
penguins banded this way had 41 percent
fewer chicks and a 44 percent lower survival rate over a decade than did colony
mates carrying just an electronic tag, a
team reports online January 12 in Nature.
In another worrisome development,
the flipper-banded penguins averaged
12. 7 days away from home on foraging
trips instead of 11. 6. “One day or two days
A metal identification band on the upper part of
a flipper (penguin near center) appears to lower
penguin survival rates and reproductive success.
is a huge difference,” says ecologist and
study coauthor Claire Saraux of the University of Strasbourg and France’s CNRS
research network. Chicks at the breeding
site eat only when a parent swims home
with food collected hundreds of kilometers, sometimes thousands of kilometers,
away. And young chicks have to build up
reserves to survive their first winter, when
parental food delivery drops off to only a
Slower foraging fits with worries that
flipper bands may be increasing drag on
penguins during swimming, Saraux says.
In a swim test in a tank, an Adélie penguin wearing a band expended 24 percent
more energy than an unbanded penguin.
“From an ethical point of view, I think
we can’t continue to band,” Saraux says.
P. Dee Boersma, a biologist at the University of Washington in Seattle who has
studied various penguin species, notes
that all bands are not created equal. “In
my view, the main point of the Nature
paper is that the bands they used were
bad for king penguins at their location.”
Saraux says flipper bands may also
not be good for science. Biologists study
penguins to see how climate change
impacts life in and around the Antarctic,
but the researchers found that environmental conditions affected banded birds
more than their unbanded counterparts.
During warmer phases of the El Niño
climate cycle, when the seafood that
penguins eat is scarce, the banded birds
showed a greater tendency to arrive late
at breeding grounds.
FROM TOP: TODD MARSHALL; BENOÎT GINESTE
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