Half of migratory animal species are in decline – many face extinction

Hundreds of migratory species – from humpback whales to wandering albatrosses – are under threat because of human activity, according to the first United Nations report on the animals. The State of the World’s Migratory Species report, released today, concludes that almost half of the migratory animals on a UN list of vulnerable species are seeing population declines. About a quarter of the listed species are at risk of extinction.

Billions of animals, belonging to more than 2000 species, travel vast distances every year for a variety of reasons, such as to find food or a place to breed. They include some of the world’s most iconic animals, says Amy Fraenkel at the UN’s Convention on the Conservation of Migratory Species of Wild Animals. Elephants, whales, dolphins and turtles are all migratory.

As a result of their wandering nature, though, these animals encounter a range of perils across their migratory routes, says Wolfgang Fiedler at the Max Planck Institute of Animal Behavior in Germany, who wasn’t involved in the report. “A stork can be endangered in central Europe by an electrocution risk that comes from wrongly built electricity pylons, in the Mediterranean region by environmental poisoning and habitat loss and in North Africa by illegal hunting.”

In 1983, an international UN treaty came into effect that aimed to protect these animals. Under the agreement, known as the Convention on Migratory Species (CMS), 1189 species were identified as being of particular interest, partly because they regularly cross national borders during their migrations.

“These are species that really require international cooperation for their survival and conservation,” says Fraenkel.

To understand how these migratory animals are faring today, Fraenkel and her colleagues conducted a comprehensive analysis of the conservation data for all the species.

Since 1990, 70 CMS-listed species – including the steppe eagle (Aquila nipalensis) and the Egyptian vulture (Neophron percnopterus) – have seen a rise in their risk of extinction. Significant population declines have hit 44 per cent of CMS-listed species, and 22 per cent are in danger of being wiped out entirely.

Fish have been hit especially hard: 97 per cent of CMS-listed fish, including scalloped hammerhead (Sphyrna lewini) and pelagic thresher (Alopias pelagicus) sharks, are either endangered or critically endangered.

The team also identified a further 399 migratory animals – including many species of albatross – that are vulnerable to extinction but that are not currently listed under CMS. About half of these are fish species.

Human activity is the biggest factor behind these alarming trends. Overfishing, pollution and habitat loss from deforestation and urbanisation all put species at risk. Climate change is a problem too.

“But there are solutions to these challenges,” says team member Kelly Malsch at the UN Environment Programme World Conservation Monitoring Centre.

“Tangible things include reducing light pollution or changing fishing gear to help reduce bycatch,” she says. “We also need to continue identifying these really important regions that species need in order to migrate and make them protected areas.”

“Such declines and conservation concerns may not seem unique, given the loss of natural areas and global biodiversity at large, but what is unique is the challenges in conserving migratory species, especially those that migrate long distances or travel across continental, national and cultural boundaries,” says Tong Mu at Princeton University, who wasn’t involved in the report. “To make the conservation of migratory species successful, most, if not all, of these threats need to be addressed at the right times at the right sites, during which large-scale coordination and collaboration is usually the key.”