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By Kate Yandell
February 25, 2013
Geladas practice deception when having illicit sex.
When mating with animals other than their pair-bonded partners, these
Ethiopian monkeys vocalize less than usual and try to hide, according to a
study published earlier this month (February 12) in
To unravel the geladas' mating habits,
researchers watched 19 groups of wild monkeys for 3 years. Geladas usually
live in units including one dominant male, one to 12 females, and up to five
subordinate males. While the dominant males father most of the young,
subordinate males have been found to foster around 17 percent of them.
When geladas have sex, both the male and female usually vocalize loudly.
But according to the new study, when a subordinate male copulates with a
female, they are quieter, especially when the dominant male was nearby. The
secret couples are also more likely to form at some distance from the
dominant male. When the deceptive male monkeys do get caught, the dominant
males sometimes retaliate by chasing and biting.
WIKIMEDIA, APRIL NOBILE
Ants start making sounds
to communicate while they are still pupae, according to a study published
online earlier this month (February 7) in
Current Biology. As soon as their hard exoskeletons begin to form, pupae
of the peat bog-dwelling species Myrmica scabrinodis start dragging their
legs across a hard spike on their abdomen, making a percussive noise in the
same manner that adults do. The sound is a cry for help and brings other
ants to the rescue.
Researchers recorded ants using their highly
sensitive microphones and found that, while soft larvae and immature pupae
were completely quiet, mature pupae were making a less refined version of
the sound adult ants make when seeking assistance, such as when under attack
by a predator. When the researchers played back the sounds of the pupae to
adults, the mature ants approached the speakers as though to guard them from
danger. When the speakers emitted white noise, the ants were indifferent.
Finally, the researchers removed mature pupae's abdominal spikes and found
that the adult ants stopped tending to them.
"What's very cool about
this paper is that researchers have shown for the first time that pupae do,
in fact, make some sort of a sound," Phil DeVries, an entomologist at the
University of New Orleans who was not involved in the study, told
ScienceNOW. "This was a very clever piece of natural history and
When female parasitic wasps
are in the neighborhood, fruit flies lay their eggs in alcohol to keep the
wasps from laying their eggs in the fly larvae, according to a study last
week (February 22) in
alcohol wards off the wasps, whose eggs would otherwise hatch in the
immature fruit flies and eat them from the inside out.
Last year, the
showed that infected fruit fly larvae guzzled alcohol once they already
had wasp larvae inside them, as a form of self-medication. Alcohol is
poisonous to parasitic wasps, while fruit flies, which often grow up in
fermenting fruit, are able to tolerate it.
This time, the researchers
placed mother fruit flies in a cage and allowed them to choose to lay their
eggs in alcohol-free dishes or dishes that were 6 percent alcohol. When they
were alone in the cage or when only male wasps were present, the flies
preferred the dishes without alcohol. But when female parasitic wasps were
in the cage, the flies preferred to lay their eggs in the alcoholic dish.
Flies with impaired sight did not show a preference for alcoholic dishes
even when wasps were present, indicating that flies were recognizing
parasites visually, even though they had never seen a parasitic wasp prior
to the experiment.
Male Eurasian jays are able to cater to females'
gustatory desires. In a study published earlier this month (February 4) in
Proceedings of the National Academy of Sciences, researchers showed that
males can judge which food to feed females by observing what they had eaten
earlier, thereby figuring out what foods they might be tired of and what
they might be craving. The study indicates that, in addition to being
thoughtful partners, jays may be able to understand each other's internal
The researchers tested male jays by having them watch
females eat one of two treats: mealworm larvae or wax moth larvae. The team
then gave the males a choice between the two foods to feed to a female and
found that the birds tended to bestow whichever food the females hadn't
The researchers thought that the jays might have
been responding to subtle social cues from the female jays. But when they
blocked the males' vision of the eating females, the males could no longer
provide the opposite food choice later on.
"It was long thought that
only humans could do this"--note the actions of others and take that
information into account in future decisions, Nicola Clayton, one of the
paper's authors and a psychologist at the University of Cambridge, told
Wired Science. "What we've shown in a series of experiments is that
doesn't seem to be the case."
WIKIMEDIA, VERA BUHL
It is well known
that bumblebees navigate to flowers based on their color, shape, and smell.
But according to a study published last week (February 22) in
Science, they can also sense the flowers' electric fields.
had no idea that this sense even existed," Thomas Seeley, a behavioral
biologist at Cornell University not involved in the study, told
Previous research had shown that insects tend to have a
positive charge, while flowers have a negative one. This aids the insects in
collecting pollen, as the difference in charge makes it stick to them more
readily. But it was unknown whether the bees were aware of the electrical
fields around them.
The researchers gave artificial flowers different
charges, filling one type with sugary syrup and another with a bitter
compound. They found that over time the bees learned to approach the flowers
with the tasty reward. But when they turned off the electric charge on the
flowers, the bees reverted to approaching them at random.
When a bee
lands on a flower, the flower's charge changes slightly. The researchers
hypothesized that the bees use their ability to sense electrical fields to
track these fluctuations. "We think bumblebees are using this ability to
perceive electrical fields to determine if flowers were recently visited by
other bumblebees and are therefore worth visiting," Daniel Robert, a
biologist at the University of Bristol and an author of the paper, told