A Norfolk sheepdog named Peggy spent most of her life working on a farm and helping her human herd animals from place to place. She was great at her job, which requires keen intelligence and the ability to listen to a shepherd’s signals. But everything changed when Peggy suddenly went deaf for unknown reasons.

Peggy was sent to an animal shelter in 2018. With the shelter full, staffers tried to find a foster family for her to spend the holidays with. Thankfully, animal welfare manager Chloe Shorten stepped up to take her in! “We decided she could stay with us temporarily while we found somewhere more permanent to take her in, but we completely fell in love with her almost immediately and it soon became clear that she wouldn’t be going anywhere!” Chloe said. “She was greasy and out of condition, untrusting, and frightened,” the shelter added.

“She soon started to bond with me and we started taking her fun places like the beach, something we don’t think she has ever experienced before,” Chloe said. “With some tender loving care and good food, Peggy soon started to adjust to life. Several months on and Peggy has blossomed into a dog who is continuing to improve daily.”

One of the biggest ways Peggy’s new family helped her adjust was getting her back to work. Working dogs are bred to do a specific job, and without a purpose, they can grow depressed and bored. So Chloe introduced the dog to hand signs and taught her to use her eyes in place of her ears while on the job. Now that she’s 10, she’s “generally retired,” but she still enjoys herding and continues to impress her family with how quickly she learns new skills.

Domestic cats, like many other animals, use smelly substances from anal sacs (肛门囊) to mark territory and communicate with other animals. The new study shows that many smelly compounds from a cat are actually made by a group of bacteria living in the anal sacs.

“Cats use a lot of smelly chemicals for signaling, and they probably don’t make the mall,” says David Coil, project scientist at the Genome Center at the University of California. The project grew out of the Kitty Biome Project, which started by researcher Holly Ganz, professor of evolution and ecology.

The researchers obtained anal sac substances from a single male Bengal cat. They extracted DNA for sequencing (排序) to identify types of bacteria, and also took samples for chemical smell analysis in Professor Cristina Davis’ laboratory in the mechanical and aerospace engineering department.

Davis’ lab focuses on technology for detecting and characterizing low levels of volatile (挥发性的) organic compounds that can be markers of health and disease, from flu in humans to a disease in fruit trees. Sequencing showed that the microbial community was not very diverse and controlled by a small number of bacterial type. “There are not a lot of players there,” Coil says.

The researchers grew the most abundant bacteria from the screen in culture. Researcher Mei Yamaguchi analyzed the volatile chemicals that the bacteria gave off. Yamaguchi and Davis were able to detect 67 volatile compounds that the bacterial cultures released. Of the compounds, 52 were also found directly in the anal sac substances. The results support the idea that the bacterial community, not the cat itself, produces many of the smells the cat uses to communicate.

Coil and colleagues want to follow up by looking at more cats. If bacteria make these smells, why do cats smell different from each other? How do cats acquire the bacteria and do they change over life? Understanding how microbes influence their smell could have wide implications for understanding smell communication in animals.

Sharks are now at the edge of extinction. Numbers of oceanic sharks have declined by an alarming 71 percent over the past 50 years, according to research published in Nature on Jan 27. “Such steep declines are shocking even to experts, especially when compared to land animal statistics,” Sonja Fordham at Shark Advocates International, a US-based nonprofit, told New Scientist magazine. This alarming data may be an underestimate of reality due to unreported fish catches, Nathan Pacoureau, the study researcher, noted.

The study analyzed 31 species; 24 now risk extinction, and three shark species are now classified as critically endangered, including the oceanic white-tip shark (远洋白鳍鲨) and great hammerhead (锤头鲨). The study found the decline hit the largest species first before impacting smaller ones over time, according to the International Union for Conservation of Nature (IUCN). It also revealed that shark finning and fishing worldwide have driven the decline. “The Indian Ocean is the worst. There is almost no (fisheries) management at all,” said Pacoureau.

“Overfishing of sharks and rays endangers the health of entire ocean ecosystems as well as food security for some countries,” said Nicholas Dulvy, a professor of Simon Fraser University in British Columbia, Canada. The researchers are calling on immediate action to secure a brighter future for these “extraordinary, irreplaceable animals”, according to the BBC.

Although the situation looks gloomy, the future of sharks is not doomed (劫数难逃的) yet. Twenty-five species have recovered, due to long-term conservation campaigns in the past decades. A couple of shark species, including the great white, have started to recover through science-based fishing limits, Fordham said. These examples “provide living proof that the world can set, and meet, ambitious biodiversity targets”, Jane Smart, global director of the International Union for Conservation of Nature, said in a statement.