Bird Behavior During a Total Solar Eclipse

Abstract

I report avian behavioral responses to a total solar eclipse on the north coast of Venezuela during the afternoon of 26 February 1998. Magnificent Frigate-birds (Fregata magnificens), Brown Pelicans (Pelecanus occidentalis), and Royal Terns (Sterna maxima), which had been foraging over the water before the eclipse, left the bay 39 (terns) or 13 (frigate-birds and pelicans) min before the eclipse became total. The frigate-birds flew inland and the pelicans went to roosts on cliffs bordering the bay. Residents of the local village, who knew the birds' behavior well, remarked that the frigate-birds and pelicans were behaving as they normally did at sunset. Laughing Gulls (Larus atricilla) ceased foraging and flew rapidly back and forth over the water in a tight flock during the 3 min 40 s of totality. Twelve minutes after the solar disc emerged, the frigate-birds and pelicans began to return to the bay, and they and the gulls resumed foraging. The terns still had not reappeared more than 1 hr after totality. Solar eclipses, although of brief duration, apparently reduce light levels sufficiently to temporarily interrupt normal avian diurnal behavior.