Mass bird deaths in Mexico likely caused by El Niño's hotter waters

The deaths of hundreds of birds along Mexico's Pacific coast in early June were likely caused by the El Niño climate phenomenon, local authorities have said.

Over the weekend of 10 and 11 June, some 300 birds of various species were found dead along the coasts of Mexico's western states of Chiapas, Oaxaca, Guerrero, Michoacan, Jalisco, Sonora and Baja California Sur. The incident occurred as the country and its surrounding oceans face an intense heatwave.

Hundreds of birds, including Neotropic Cormorants, were found dead (Clive Daelman).

Authorities had initially suspected bird flu, but a joint effort from the country's agriculture and environment ministries concluded the most likely reason was warmer oceans resulting from El Niño. With warmer waters, fish tend to swim lower in search of colder waters, which prevents seabirds from successfully hunting for their food.

The periodic natural phenomenon, which lasts between months and years, warms the Pacific Ocean fuelling tropical cyclones, floods and rainfall across the Americas and elsewhere. The U.S. National Oceanic and Atmospheric Administration (NOAA) earlier this month declared that an El Niño is now under way, after three years dominated by the cooler La Niña pattern.