How animals reacted to the eclipse: Sheep froze, chickens grew sleepy and a donkey’s heart began racing

More than 30 animals in Spain were fitted with sensors as scientists tracked what happened on the ground while millions of people watched the eclipse in the sky.

Early findings from the universities of Zaragoza and Salamanca showed no single animal response. Chickens reacted mainly to the sudden loss of light, sheep moved almost as one herd, and equines varied substantially from one animal to another.

At the University of Zaragoza’s veterinary school, researchers monitored 10 sheep for six days. Near the phenomenon’s peak, between 20:24 and 20:28, the herd’s average activity dropped by about 40%. All 10 sheep stopped almost simultaneously, and nine remained less active than usual shortly afterward. Their physiological responses differed, however. Some sheep had slower heart rates, others faster ones, and body temperature showed no shared pattern.

Sixteen chickens monitored in Zaragoza did not reduce their total daily activity, but changed when they moved. After the peak, they remained still temporarily and began displaying dusk-like behavior about 18 minutes earlier. Near Burgos, five of six chickens shifted into evening inactivity 40 to 60 minutes early, while all six became less active than expected and showed a longer slowdown in heart function.

Three mares, a mule and a donkey were monitored in a wetland area of Teruel province. Their initial responses differed, but all five later became less active, with average activity falling 18.6%. The donkey first reduced its movements, then exceeded its usual activity levels. Its heart rate rose from 46 beats per minute at 20:25 to about 60 to 63 during and after the eclipse peak.