Birds the world over are facing unprecedented challenges, a new report has found, with populations plummeting and a growing number of species under threat. But better data from the field is making it possible to pinpoint exactly where and why some categories of birds are at particular risk, paving the way for strategies designed to improve their situations.
"Our assessment unfortunately shows that birds are in decline," said Leon Bennun, director of science, information and policy for BirdLife International, a United Kingdom-led partnership of conservation groups that is meeting this week in Ottawa. "It also shows what we can do about the problem."
The report, released on Thursday, is the organization's most comprehensive snapshot yet of the state of the world's birds. It's the first such assessment since 2008. It finds a total of 1,313 bird species are threatened worldwide – many because of multiple factors. The issues range from invasive species to climate change and especially to the rise of big farming.
"We're very concerned about the spread of industrial-scale agriculture," said Stuart Butchart, a conservation biologist and BirdLife's head of science.
Dr. Butchart said the clearing of virgin forest for palm oil plantations in Southeast Asia, as well as the intensification of farming in Europe and elsewhere, are examples of how modern agriculture is transforming the planet and making it much less friendly to birds.
The pattern is also apparent in Canada, where grassland birds have been among the hardest hit, partly because of the disappearance of natural prairie but also because hay fields and pastures have increasingly been repurposed for corn and soy.
Other birds faring poorly in Canada include those that subsist on flying insects. Even the barn swallow, an iconic and common species across rural Canada, has sustained a shocking 70- to 80-per-cent loss in population since 1970, said Jon McCracken, director of national programs for Bird Studies Canada, which is based in Port Rowan, Ont.
"It's mathematically impossible to sustain these declines for more than a few decades before things blank out entirely," he said.
There are also some good news stories. For example, birds of prey and waterfowl are on the rebound in Canada due to conservation efforts and a reduction of contaminants in the environment, such as the chemical DDT.
Internationally, the new report has found birds that feed in the open ocean have been in serious decline, in part because they are susceptible to being caught up in fishing lines and nets, leading to hundreds of thousands of bird deaths a year. The recognition of this problem has led conservation groups to work with the fishing industry to develop equipment that is less likely to harm birds, Dr. Butchart said.
He added that birds are an environmental bellwether, and that the conservation of bird habitat ultimately benefits humanity. "What we need now," he said, "is to scale up the resources that are mobilized, the actions that are taken in order to save nature, upon which we all depend."