Latest news with #Aves
Yahoo
02-05-2025
- Science
- Yahoo
Scientists Mapped the Evolution of 11,000 Bird Species to Build the Avian Tree of Life
Birds are the most diverse land vertebrate on the planet, and now scientists have constructed a complete evolutionary tree of the 11,000 or so known species. This data came from hundreds of studies written from 1990 to 2024, as well as additional taxonomic information on more than a thousand birds not included in those studies. This data is now part of the Open Tree of Life (OpenTree) project—a collaboration between evolutionary biologists and taxonomists which aims to construct the evolutionary history of all known species on the planet. When it comes to diversity, no animal can quite hold a candle to birds. Being the most genetically varied land vertebrate on the planet, the class Aves thrive on every continent. And they're also impressive survivors, being as they're the direct descendants of the avian dinosaurs that survived the K-T Extinction event some 66 million years ago. Those many millions of years have given birds time to evolve into some 11,000 species, and keeping track of all those species—not to mention their evolutionary history–can be quite the challenge. Luckily, scientists from the University of California Merced and Cornell Lab of Ornithology decided that challenge was one they wanted to meet and proceeded to pour over 262 studies related to 9,239 bird species published from 1990 to 2024. After combining additional data on the 1,800 or so species not included in these studies, the team formed a complete map of avian evolutionary history. The results of this work were detailed in the journal Proceedings of the National Academies of Science (PNAS) 'People love birds, and a lot of people work on birds,' Emily Jane McTavish, the lead author of the study from UC Merced, said in a press statement. 'People publish scientific papers about birds' evolutionary relationships all the time. We synthesized all the data to have unified information all in one place.' For years, McTavish worked on software known as the Open Tree of Life (OpenTree) project, a collaboration between evolutionary biologists and taxonomists to build a comprehensive evolutionary tree of all species on the planet—not just birds. By creating a complete evolutionary history of all known birds on the planet, the experts hope to gather research in one place and make startlingly new discoveries in the future. 'Many dozens of bird phylogenies (studies of evolutionary histories using genetics) get published every year, yet their findings—with implications for everything from taxonomy to our understanding of ancestral characters—aren't necessarily being used for downstream research,' Eliot Miller, a visiting scientist to Cornell Lab and senior author of the study, said in a press statement. 'Our project should help to close this research loop so that these studies and their findings are better incorporated into follow-up research.' Because Cornell Lab is also in charge of popular citizen science bird tools like Merlin and eBird, this updated tree can also link with those datasets, providing even better models for scientists and birders alike. The team also designed the dataset to update automatically as new phylogenetic information about birds becomes available. Crucially, similar techniques used to construct this evolutionary tree can be applied to other groups of species as well, slowly revealing the incredible and inter-related animal diversity that spans the globe. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
The Guardian
10-02-2025
- Science
- The Guardian
More than 1,100 dead sea turtles washed up along southern India's coastline
More than 1,100 dead olive ridley sea turtles have washed ashore on the beaches of Tamil Nadu state in southern India this January. 'I never heard [of] such large numbers of turtles stranded at any beaches of Tamil Nadu at least in the last three decades,' Kuppusamy Sivakumar, an ecology professor at Pondicherry University said. Most of the washed up turtles were found near the state capital, Chennai. Every year, olive ridley turtles (Lepidochelys olivacea) gather off India's coast to breed. Female turtles come ashore to the beaches where they hatched to lay their own eggs, while the males remain in the water. Typically, between 100 and 150 turtles nest on Chennai's beaches annually, so the stranding of more than 1,000 turtles is surprising, Sivakumar said. Chennai resident Rajiv Rai said he had spotted about 80 dead turtles on a 2km (1.24 mile) stretch of beach near his home. He said he alerted the state's forest department, whose staff bury the carcasses, although the burials are now lagging. An initial necropsy of one carcass revealed lung lesions; many dead turtles had bulging eyes. Both observations indicate the turtles are likely to have died from suffocation and drowning, Yuvan Aves, a Chennai-based environmental activist said. The official postmortem report has not yet been made public. Aves said he had also observed an unusually large number of male carcasses on the beach. The reasons for the mass deaths are unclear. However, Sivakumar said both male and female turtles could have gathered near nesting beaches to breed. If there was net fishing in the area, the turtles, which need to surface to breathe, may have become entangled and drowned. If that were the case, Sivakumar said, it was difficult to say whether the turtles got caught in fishing nets near Chennai or further away, then ended up off Chennai due to winds or currents. Aves said commercial fishing vessels operating in Chennai's waters often do not abide by local laws, which was likely to have contributed to deaths. Tamil Nadu, for example, has banned trawlers within five nautical miles (9km) from shore, but the law is not typically enforced. Trawler nets must also have turtle excluder devices installed, but 'notoriously, nobody has it,' Aves said. After media coverage of the crisis, the Tamil Nadu government caught 24 trawler boats operating illegally in Chennai's waters, and has created a special taskforce in response. The government said in a release that a joint patrol team is now monitoring boats and ships in the area. Manish Meena, Chennai's wildlife warden, said that 'night patrols have been intensified to protect hatchlings'. The scale of death of a species that was once endangered and has only partly recovered due to conservation efforts 'exceeds one's capacity of feeling,' Aves said. 'You can stand on the coast right now anywhere in Chennai and every few strides, you can see bulge-eyed turtles till the horizon.' This story was originally published by Mongabay
