Some bacteria trigger their own destruction by making their environment uninhabitable, a process that researchers have named ‘ecological suicide’. Many microbes produce by-products that alter the acidity of their environment, but large pH changes can cause their cells to burst.
Birds share more readily after being given the avian equivalent of oxytocin, a hormone linked with social bonding and maternal behaviour in mammals.
The hormone mesotocin boosts gregariousness in birds. To see what other powers it might have, Juan Duque and his colleagues at the University of Nebraska–Lincoln trained caged pinyon jays (Gymnorhinus cyanocephalus) to choose between sending a gift of a mealworm to a nearby jay or sending the treat to an empty cage.
The flippers of sea turtles are superbly adapted for swimming, leading many scientists to assume that the flap-like appendages are not suited to other tasks. But Jessica Fujii at the Monterey Bay Aquarium in California and her colleagues have compiled evidence that turtles use their flippers to handle and eat prey.
Scientists have long puzzled over why marine mammals tend to be much larger than land mammals. An analysis of nearly 7,000 living and extinct species suggests that sea-going mammals grew big to keep warm. William Gearty at Stanford University in California and his colleagues found that of the four groups of marine mammals in the oceans today, three have evolved an average mass of about 500 kilograms: sea cows; seals and their relatives; and toothed whales such as dolphins.
An enhanced version of a common screening test for cervical cancer can also detect early-stage ovarian and endometrial cancers. The Papanicolaou test, also known as the Pap test or cervical smear, catches cervical cancers while they are still curable. But reliable screening tests for endometrial and ovarian cancers are lacking, and these malignancies often metastasize before they cause symptoms.
Scientists have smashed a size limit on the range of proteins that can be imaged in 3D with electron microscopy.
Proteins can be reconstructed in 3D detail by photographing samples under a transmission electron microscope at temperatures below −150°C. This technique, known as cryo-electron microscopy, is used to image viruses and other structures that contain multiple protein molecules. But the technique is difficult to apply to individual proteins because of their small size.
Hungry seals provide direct evidence that plastic travels up the ocean food chain from prey to predator.
Researchers have long assumed that marine predators ingest microscopic fragments of plastic by eating prey filled with it. To test this idea, Penelope Lindeque at the Plymouth Marine Laboratory, UK, and her team analysed faeces from captive male grey seals (Halichoerus grypus) at a seal sanctuary...
A new study identified 142 dams currently in operation or under construction in the Andes headwaters of the Amazon, twice the number previously estimated. An additional 160 are in the planning stages.
If proposed Andes dams go ahead, sediment transport to the Amazon floodplains could cease, blocking freshwater fish migratory routes, disrupting flow and flood regimes, and threatening food security for downstream communities, impacting up to 30 million people.
Most dams to date are on the tribu...
Climate change could force millions of king penguins to seek new breeding grounds by the end of the century.
King penguins (Aptenodytes patagonicus) breed on islands throughout the Southern Ocean and feed where the ocean’s warm and cold waters meet. Emiliano Trucchi at the University of Ferrara in Italy, Céline Le Bohec at the...
Despite a 76 percent decline in deforestation rates between 2003 and 2015, the incidence of forest fires is increasing in Brazil, with new research linking the rise in fires not only to deforestation, but also to severe droughts.
Seeds consumed by a mouse can still sprout and grow — if the mouse is eaten by a rattlesnake. Randall Reiserer at the University of California, Berkeley, and his colleagues examined 50 museum specimens of rattlesnake encompassing three species: sidewinder (Crotalus cerastes), Mojave rattlesnake (C. scutulatus) and Southwestern speckled rattlesnake (C. pyrrhus). In the snakes’ stomachs and intestines, the researchers discovered a total of 971 seeds that had been collected by rodents...
An arachnid found in 100-million-year-old Burmese amber from Myanmar boasts a curious mix of characteristics. The spider-like creature (Chimerarachne yingi) has a tail-like appendage similar to those of other early arachnids, but also has traits seen in modern spiders, such as multi-segment silk-spinning organs.
Plants are locked in an ancient arms race with hostile viruses, but genome editing is giving crops the upper hand.
In 2011, Noah Phiri was working with local farmers in Kenya to combat the fungal pathogen that causes coffee leaf rust when another virulent plant disease began wiping out maize in the country’s southwest corner. Infected plants developed pale streaks on their leaves, then wilted and died. Some farmers lost as much as 90 percent of their crop that year.
Sounds from noisy motorboats prevent fish from learning to recognize new predators.
Maud Ferrari at the University of Saskatchewan in Saskatoon, Canada, and her colleagues played recordings of either the natural sounds heard near a coral reef or the sounds of both a reef and a motorized dinghy to juvenile coral-reef damselfish (Pomacentrus amboinensis).