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First global survey finds 44% of migratory species in decline

Some migratory species are improving but 22% of those listed are threatened with extinction, including nearly all the fish.

A U.N. treaty covers 1,189 species in need of international protection.
A U.N. treaty covers 1,189 species in need of international protection. (AN/Jordi Rubies/Unsplash)

Climate change, pollution, illegal hunting and fishing, and loss of habitat increasingly endanger the lives of animal species that often fly, swim or walk long distances to breed or find food.

The first-ever U.N. survey on migratory animals worldwide finds our efforts to protect these iconic species – sea turtles, whales, sharks, elephants, songbirds, monarch butterflies and many others – are deteriorating, putting the survival of many of them at risk.

The survey unveiled on Monday points to declining populations among 44% of the 1,189 animals listed as needing international protection under the Convention on Migratory Species.

The biodiversity treaty, known as CMS, is the only one that is specifically geared toward the conservation of migratory species, their habitats and migration routes. It aims to protect wildlife through international cooperation and coordinated action.

Some migratory species are improving, the survey shows, but more than one-in-five, or 22%, of all species listed under the treaty are threatened with extinction, including nearly all of the fish.

But the growing extinction risk for migratory species globally extends beyond those covered by the treaty.

The survey contains data on 3,000 non-CMS listed migratory species, and shows 399 migratory species not covered by the treaty that are threatened or near-threatened with extinction.

Some of the data comes from the International Union for Conservation of Nature’s Red List, which tracks the extinction risk for species and is used by governments to reduce biodiversity loss.

"Unsustainable human activities are jeopardizing the future of migratory species – creatures who not only act as indicators of environmental change, but play an integral role in maintaining the function and resilience of our planet’s complex ecosystems,” said Inger Andersen, U.N. Environment Program's executive director.

More international cooperation needed

The survey's release coincided with the opening of a U.N. wildlife conference hosted by Samarkand, Uzbekistan, where delegates will evaluate conservation proposals and whether to add new species to the treaty's list.

The loss and fragmentation of habitat and barriers to migration – such as highways, dams, and agricultural development – remain a major threat for migratory species.

While about half the sites identified as being important for migratory species receive some level of protection, many still face unsustainable levels of human-caused pressure.

Other key threats to animals on the move are pollution, including light and noise, the warming climate, and invasive species.

“The good news is that the actions that are needed are clear,” said Amy Fraenkel, the CMS executive secretary. "When species cross national borders, their survival depends on the efforts of all countries in which they are found."

At the national level, she said, more needs to be done to reduce illegal hunting, eliminate the phenomenon of bycatch – mainly fish and other marine life hooked or entangled in fishing gear meant to catch other species – and protect important sites for migratory species.

The main recommendations are:

  • Strengthen and expand efforts to tackle illegal and unsustainable taking of migratory species and incidental capture of non-target species.
  • Increase actions to identify, protect, connect and effectively manage important sites for migratory species.
  • Urgently address those species in most danger of extinction, including nearly all CMS-listed fish species.
  • Scale up efforts to tackle climate change and light, noise, chemical and plastic pollution.
  • Consider expanding CMS listings to include more at-risk migratory species in need of national and international attention.