Decoding Pandas’ Come-Hither Calls
During mating season, the solitary mammals bleat important information to each other through their dense bamboo habitat.
By Douglas Quenqua
- For solitary animals, giant pandas have an awful lot to say to one another. Their vocal repertoire comprises more than a dozen distinct grunts, barks and squeaks, most of which amount to some version of “leave me alone.”
But when mating season rolls
around, both male and female giant pandas turn to their preferred
come-hither call: a husky, rapid vibrato that’s commonly known as the
bleat.
A Male Panda’s Bleat
A recording of a male panda’s vocalization.A Female Panda’s Bleat
A recording of a female panda’s vocalization.
Advertisement
The bleat not only alerts other pandas to the presence of an available mate, it contains important information about the vocalist’s size and identity.
Given the dense bamboo thicket that limits visual contact in most panda
habitats and the brevity of panda mating season — females ovulate just
once a year and can conceive for only a few days — the pandas’ ability
to perceive the bleat is critical to reproduction among this
once-endangered species.
Now, researchers have determined that the bleat works best as a local call. A panda can discern aspects of a caller’s identity. like its size, from a bleat within about 65 feet, but the caller’s gender is only perceptible within about 33 feet, according to a study published Thursday in Scientific Reports.
You have 1 free article remaining.
Subscribe to The Times
Subscribe to The Times
Megan
Owen, a conservation ecologist at the San Diego Zoo Institute for
Conservation Research and an author of the study, offered a human
analogy for how this ability works.
“If
you’re walking into a crowded room and someone calls out your name,
there’s a certain point where you can identify who that is, or maybe you
can identify that it’s a male or female that is calling your name,” she
said. “There’s information that’s encoded in that call, but that
information degrades over distance.”
[Like the Science Times page on Facebook. | Sign up for the Science Times newsletter.]
To
conduct the study, Dr. Owen and her colleagues — including Ben
Charlton, another San Diego institute researcher who has studied panda
bleats — obtained recordings of giant pandas from Chengdu, China, during
breeding season. They then played those recordings through a speaker in
a section of the San Diego Zoo Safari Park that contains bamboo similar
in type and density to a typical panda habitat. By placing recording
devices throughout the bamboo, the researchers were able to capture and
analyze the bleats from various distances.
Advertisement
“We
measured how far the transmissions were received as well as the
different frequency components of those transmissions,” said Dr. Owen.
The
ability to hear and respond to bleats could affect panda populations
beyond simple reproduction, said Dr. Owen. Male pandas must often
compete with one another to find mates, and the identifying information
contained in a bleat can help them decide which ones to tangle with.
“If
you can ID an individual that you’ve had a competitive interaction
with, that’s valuable information as to whether that’s a bigger, tougher
male than you are, and whether it’s worth taking that risk,” she said.
“There are real tangible benefits to knowing who you’re dealing with
when you’re out there.”
Giant pandas
climbed off the endangered species list in 2016 following decades of
rescue efforts by conservationists. But with fewer than 2,000 now living
in the mountains of Western China — the only region where they are
found in the wild — the much-beloved animal is still considered
vulnerable. Last year, a study found that panda habitats are in serious decline, which could make their rebound a short-lived victory.
The
current study could help refine the efforts of conservationist trying
to encourage pandas to breed within those dwindling habitats.
“Everything we learn about their habitat helps us better understand how
its degradation may influence their biology and ecology,” said Dr. Owen.
“It definitely adds an important piece of information to the puzzle of
panda communication.”
Earlier reporting on pandas
No comments