Hundreds of birds turned up dead under mysterious conditions — is El Niño the ruthless killer?

In an ecological true crime playing out on Mexico’s Pacific Coast, hundreds of seabirds have turned up dead on ocean beaches — and the prime suspect in the case has recently shifted from avian flu to the climatological phenomenon El Niño.

What happened?

Originally, authorities assumed the deaths of the birds — found earlier this year from the southern state of Chiapas north to Baja California — would be attributed to the latest strain of bird flu, reported the Associated Press.

That was logical. An ongoing outbreak of this disease has led to unprecedented wild bird mortality in the past few years, involving possibly millions of animals across five continents.

However, the 300-some dead birds in Mexico — most of which were seagoing types, including shearwaters, gulls, and pelicans — turned out to have died of starvation, not flu, which the Mexican government reported in June after testing tissue samples.

This turned suspicion toward El Niño. The naturally occurring climate cycle, whose effects are amplified by human-induced global warming, brings warm surface water to the ocean off Mexico. Fish that seabirds normally eat dive lower to reach colder water — out of birds’ reach.

“The starvation is happening because of … global warming and the El Niño phenomenon, in which the water temperatures are rising, and that makes the fish that [birds] feed on go deeper,” Roberto Navarro, a Mexican official, said in a translated statement shared by Reuters and Yahoo! Life.

Why are bird deaths due to El Niño concerning?

Although El Niño is part of a natural cycle, its effects are intensifying, and evidence suggests a strong El Niño year, according to the National Weather Service.

The coastal casualties in Mexico, along with other downed fliers in South America, may be the seabird version of canaries in a coal mine. The deaths of the birds could foretell significant impacts ahead — for people and animals.

El Niño is the “warming” part of the climate cycle and can bring an intensification of droughts and deluges, depending on your location. Hazards such as storms may be amplified when natural shifts are compounded by climate change.

What can I do about El Niño and birds?

El Niño is a natural event that can take nine to 12 months to run its course, but we can all do things to reduce long-term climate changes that intensify its effects.

The United Nations lists actions for individuals through its Act Now campaign. This program lets you learn about sustainability and track the impact of activities through an app.

To understand impacts on wildlife, we can participate in citizen science projects, including iNaturalist’s. If you find a dead bird in the U.S., experts recommend you report it.

Because, who knows? You might help solve an environmental mystery.

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