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The world’s first-of-its-kind catalog of bird forms is an ecological ‘gold mine’ | Science

In 2012, evolutionary biologist Catherine Sheard began an ambitious PhD. project: measure the shape of all types of passerines, or perching birds, in the world. “I thought, ‘That’s about 6,000 species, that almost seems doable,'” Sheard said. It was, and his project catalyzed an international effort to measure every bird in the world.

Today, a team of 115 researchers from 30 countries, led by Ph.D. de Sheard. Joseph Tobias, an ecologist at Imperial College London, has published anatomical measurements of 11,009 species of living birds, not just passerines like robins, but also ducks and penguins, vultures and ostriches. “It’s a gold mine,” says geneticist Nancy Chen of the University of Rochester, who was not involved in the project.

The open-source dataset, called AVONET, debuts this month in a special issue of Ecology Letters as well as articles describing its value for studying the evolution and ecology of birds, as well as the impact of climate and habitat change on vulnerable species. “For the first time, we’re gaining a holistic, quantitative perspective on bird biodiversity, which is truly amazing,” says ecologist Brian Enquist of the University of Arizona.

Tobias was inspired by a massive plant metrics database called TRY, which contains millions of records of leaf shape, chemical makeup, average bloom dates, and more. By correlating these records with other types of data such as remote sensing, plant ecologists have studied a wide range of questions, including how quickly plant diversity declines when habitats are fragmented. Yet TRY has details for less than half of the world’s 391,000 plant species, limiting its ability to answer some questions.

Assembling a comprehensive bird dataset began to look feasible after Sheard finished his efforts, carefully wielding calipers on sometimes fragile specimens to measure around 80 birds a day at five major UK museums and the United States.

In total, the authors provided data from 78 collections and a few field studies. On average, they measured eight to nine individuals for each species. To fill in the last few hundred missing species, Tobias networked and called researchers from around the world. “At this point, it was a labor of love,” he says.

The AVONET dataset contains 11 morphological traits, such as beak shape and wing length, for 90,020 individual birds from 181 countries. “It’s phenomenal what they’ve done,” says Çağan S̨ekercioğlu, an ornithologist and conservation ecologist at the University of Utah, who has created a dataset of the birds’ ecological characteristics, including their diet. and their habitat.

Earlier and incomplete versions of AVONET have already provided information. Sheard reported in 2020 in Nature Communication that geographical distributions of species, documented by previous studies, correlate with flight ability, as revealed by the ratio of hand length to wing length. Compared to migratory birds of temperate regions, sedentary birds of the tropics have stumpier wings, poorer flight, and more restricted ranges. This link between wing anatomy and flight range could help researchers assess the vulnerability of species to damage from habitat destruction or climate change, as poorer pilots may not be able to to disperse from inhospitable environments, says S̨ekercioğlu.

The articles in the special issue report new discoveries. One shows that the evolution of flight has reduced birds’ reliance on weapons, such as bone spurs, likely because these tusks add extra weight. Another confirms that communities of bird species with greater morph diversity, such as specialized beaks for niche diets, tend to be at lower risk of extinction.

Other teams can apply the data to new questions. “It really democratizes data housed in museums,” says Sahas Barve, postdoctoral fellow at the Smithsonian National Museum of Natural History. “Not only is it available to students around the world, but it is also available to scientists in the countries from which these specimens were originally taken.”

Future studies can combine measurements of body shape with genetic data, geographic distributions and environmental conditions to test theories about the evolution of birds and their role in ecosystems, says AVONET co-author Carsten Rahbek from the University of Copenhagen. For example, AVONET measurements can help estimate the maximum fruit size a species can eat and roughly how far it can travel before defecating seeds – clues to which plants it might be spreading and with which. efficiency.

Researchers could then use the dataset to predict the ecological consequences of global changes, such as deforestation and warming. “It’s the door to the future,” says Rahbek. For example, using data on specialized beaked species for unusual flowers, researchers could predict which plant species are at greater risk of extinction if their avian pollinators disappear. In some tropical countries, large fruit-eating birds are hunted intensively, and their loss could reduce seed dispersal. Around the world, conservation decisions “are going to have to be made fast and furiously,” says Enquist. “Datasets like this allow us to anticipate what is going to happen and help us know what to do next.”

Tobias and others plan to continue improving the dataset by filling in missing data for around 100 species. They will also measure more individuals and add other types of life history and behavioral information. For now, the dataset exists as a spreadsheet in a companion file to an article. Creating a community database and website like TRY would require new funding, as well as mechanisms to validate newly uploaded data, such as actions taken when researchers or volunteers capture and band live birds. . “If you put it all together,” Tobias says, “you could get an incredible resource.