Lights out

 作者:温援     |      日期:2019-03-07 06:03:00
By Julia Hinde Wildlife buffs will join astronomers at the total solar eclipse in southern Africa on 21 June. More than 200 enthusiasts will gather in Zimbabwe for one of the world’s first large-scale studies of how wild animals behave during an eclipse. During the few minutes of darkness while the Moon completely blots out the Sun, the temperature drops dramatically and it becomes eerily quiet. There are some small studies and plenty of anecdotal evidence to indicate that birds head back to their nests to roost, goats come down from the mountains, and nocturnal animals prepare for a night’s foraging. Members of Wildlife and Environment Zimbabwe, a voluntary organisation made up mostly of amateur wildlife enthusiasts, will be setting up camp in the Mana Pools National Park in northern Zimbabwe for two days either side of the eclipse. The park is directly in the path of the total solar eclipse, which will be the first of the 21st century. Astronomers predict that the park will be plunged into darkness for a full three minutes when the Moon passes over the face of the Sun at 1518 local time. Meteorologists will record temperature, light levels and wind changes during the eclipse. Small teams of researchers will track mammals and birds – including elephants and lions – to record their normal behaviour at sunrise, sunset and mid-afternoon. Teams will record what they find and see every five minutes for up to two-and-a-half hours at a time. They will compare behaviour during the eclipse with the animals’ activity on days before and after the event. “We have anecdotal records dating back to 1200,” says Shirley Cormack, president of Wildlife and Environment Zimbabwe, but there have been very few large-scale studies. “We are following up the anecdotal reports and trying to give them a statistical backdrop,” she says. The observers will also be joined by Richard Estes, an expert in African animals’ behaviour and an associate at the Harvard Museum of Natural History in Boston, and Paul Murdin of Britain’s Particle Physics and Astronomy Research Council. Murdin predicts that insects will be strongly affected, as they are highly sensitive to temperature. “One feels uneasy during an eclipse,” he says. “The temperature falls, there’s a chill, insects will suddenly become very quiet. In terms of human reactions, as well as seeing the spectacle in the sky, there are many physiological effects. I would expect sensitive animals such as elephants to notice these things too.” Estes thinks the mammals most likely to be affected by the sudden nightfall of the eclipse are bats, bushbabies, hippos,