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Does the unexpected darkness during a solar eclipse have any effect on birds?

Last week a total solar eclipse swept over the Northern Hemisphere; from the Faroe Islands to Asia, the sky went dim as the moon shrouded the sun. There’s a lot of legend and superstition surrounding this phenomenon; one of them is that eclipses cause singing birds to fall silent.

We don’t know a great deal about how birds respond during a total solar eclipse (the opportunities to study it are limited to twice a year). But scientists think that the eerie avian silence occurs because diurnal birds mistake the disappearing light for night, taking it as a cue to quit their chirruping.

Researchers who have studied the event say that sometimes nocturnal birds like owls will fill in the missing audio, punctuating the brief moment of afternoon darkness with their untimely hooting and barking.

But sound isn’t the only way to gauge how birds feel about the dark. In February 1979 an ornithologist named Range D. Bayer made it his mission to observe how waterbirds at the Yaquina Estuary in Oregon responded to a solar eclipse. He noted that as darkness approached, birds stopped feeding and clustered together, as if they were seeking safety. Some birds, like gulls, even issued calls of alarm in flight. Bayer surmised that the birds were “disoriented” by the darkness and felt threatened, as if a predator was approaching them.

This response may just be species-specific, though. Some birds, such as geese, simply fly back to their roosts during an eclipse. A 2001 study on African birds in Zimbabwe revealed that other species, like herons and waders, remained unruffled by the skyward changes. The researchers noted that wading birds kept on wading, and that herons kept on fishing, even when the heavens were pitch black.

Last week, while the birds were busy resetting their internal clocks, people in Europe took the time to step out and gawk at the four-hour spectacle. Many pulled out their cameras to record the solar hiatus, capturing celestial silhouettes of birds along the way. Take a look at some of the striking shots at One Green Planet