[BLOG] Some Friday links

• Bad Astronomer Phil Plait notes how the dinosaurs seem to have been killed off 65 million years ago by a combination of geological and astronomical catastrophes.
• Centauri Dreams examines Kepler 1658b, a hot Jupiter in a close orbit around an old star.
• The Crux reports on the continuing search for Planet Nine in the orbits of distant solar system objects.
• D-Brief notes how researchers have begun to study the archaeological records of otters.
• Cody Delistraty profiles author and journalist John Lanchester.
• Far Outliers reports on the terrible violence between Hindus and Muslims preceding partition in Calcutta.
• L.M. Sacasas at The Frailest Thing suggests the carnival of the online world, full of hidden work, is actually an unsatisfying false carnival.
• Hornet Stories reports that São Paulo LGBTQ cultural centre and homeless shelter Casa 1 is facing closure thanks to cuts by the homophobic new government.
• io9 reports on one fan’s attempt to use machine learning to produce a HD version of Deep Space Nine.
• JSTOR Daily takes a look at the increasing trend, at least in the United States and the United Kingdom, to deport long-term residents lacking sufficiently secure residency rights.
• Lawyers, Guns and Money looks at the literally medieval epidemics raging among the homeless of California.
• Marginal Revolution considers how the Book of Genesis can be read as a story of increasing technology driving improved living standards and economic growth.
• The NYR Daily interviews Lénaïg Bredoux about #MeToo in France.
• The Planetary Society Blog considers the subtle differences in colour between ice giants Uranus and Neptune, one greenish and the other a blue, and the causes of this difference.
• The Speed River Journal’s Van Waffle shares beautiful photos of ice on a stream as he talks about his creative process.
• Starts With A Bang’s Ethan Siegel considers what the universe was like back when the Earth was forming.
• Window on Eurasia reports on a statement made by the government of Belarus that the survival of the Belarusian language is a guarantor of national security.
• Arnold Zwicky was kind enough to share his handout for the semiotics gathering SemFest20.

[LINK] “Eavesdropping on the Secret Social World of Giant Otters”

Wired‘s Nadia Drake reports on recent progress made in deciphering the surprisingly complex communications systems of giant otters. (The paper referred to is here.)

Giant river otters (Pteronura brasiliensis) are also known as river wolves. Like wolves, they live in large, complex social groups. And like wolves, they sometimes mark their territories and communicate by howling. Found mostly in the Amazon basin (the otters in the gallery were photographed in Peru) and Brazilian Pantanal, giant otters can grow to nearly 6 feet in length and are the largest otter species on the planet.

In addition to being huge, giant river otters also have a (relatively) huge vocabulary. Adults communicate using an array of 22 sounds, researchers report today in PLoS ONE. Otter pups are born making noise, and generate an additional 11 sounds. Scientists suspect the animals’ vocal complexity reflects the complexity of giant river otters’ social structure, which includes multigenerational family groups of more than a dozen individuals.

Learning the language of these Amazonian river wolves meant studying five families of wild otters in Peru and three captive otter families kept in German zoos. Scientists recorded the otters’ different vocalizations (see some of the videos here) and the contexts in which those sounds emerged. Then they compared the ways in which the wild and captive otters communicated with one another.

Ultimately, the team classified and described 22 different adult otter noises, which is a few more than previous researchers had found. Some of the sounds, like the warning sound Hah!, are made by all age groups. Snorts are also an alert, and scientists think information about the severity of an approaching threat is encoded in the duration and number of snorts. Barking and humming noises can be greetings, or signals that the group is changing direction and going to hunt somewhere else. And then there are the mating calls, the begging calls, the simple greetings, and more.

In general, scientists suspect that animals with more complex social structures have more complex vocabularies. Among otter species, this seems to be true. Mostly solitary otters, such as the neotropical and Eurasian otters, have vocal repertoires with fewer than 10 sounds. Semi-social otters, such as the Cape clawless otter, have a few more. The sea otters found off the coast of California make about 10 distinct vocalizations. And the giant river otters, with their complicated social lives—seriously, they have all the drama—make the most noises.