by As ominous as it may look, the total eclipse of the sun in early April will not cause frenzy in the animal kingdom.
But aside, a solar eclipse has an effect on birds, insects and others, because of how much these animals depend on the sun for orientation.
“Light is a ubiquitous cue,” said Cecilia Nilsson, who studies bird and insect movement at Lund University in Sweden.
“But it’s also a clue that’s very difficult to manipulate in any way, as a researcher. You can’t turn the sun off and on.”
That’s why she and a team of researchers used the last eclipse that shadowed parts of the United States, in August 2017, to study the movement of birds and insects. They used a network of weather surveillance radars, and the stations collect continuous data, which tells us about the weather but can also pick up biological signatures, such as migrating birds.
The birds…
The team’s hypothesis was that certain birds would take to the skies during the eclipse, as sunset during the autumn migration season is often when some flocks take off.
“They didn’t do that at all,” Nilsson told CBC News from Lund, Sweden. “There was a reduction in activity in the air. So they were moving around a lot less and there were fewer birds in the air.”
In fact, coming up to the totality of the eclipse, the birds began to show winding behavior. Nilsson theorized that they felt the pale sky as a gathering storm, which would be dangerous to fly into. But any impact disappeared when the sun came back about three minutes later.
“He was kind of like ‘huh?’ moment … and then pretty quickly returning to normal,” Nilsson said.
… And the bees
Nilsson’s research indicated that something happened at the moment, with several radar stations picking up “sudden peaks in the number of biological targets at low altitude.”
The theory is that nocturnal insects, which respond much faster to the onset of night, were active. It has long been known, for example, that honey bees rely on the sun for navigation — in fact it was a Nobel Prize-winning discovery, says Dezene Huber, a professor at the University of Northern British Columbia.
“The orientation of the dance on the comb is related to the orientation of the sun outside the hive,” said Huber. This lets the whole hive know how to get to food.
He says depending on when these insects are active – whether diurnal or nocturnal – there may be different responses to an eclipse. For example, animals that are active during the day may have the same approach, as the eclipse may involve storms.
“I would expect that some insects like honey bees might have some trouble navigating briefly,” Huber told CBC News from Prince George, B.C. But life is coming back soon, because there are other ways these animals also consider the position of the sun in the sky.
“When it’s bright again, they’ll be able to continue their way toward the flowers or back toward the hive,” Huber explained.
Hugh Danks, a retired entomologist, agrees.
“These temporary effects of a solar eclipse are unlikely to be much more dramatic than the ‘normal’ effects of weather changes,” Danks wrote in an email to CBC News.
A rare opportunity
Beyond birds and insects, zoos along the path of totality have a unique opportunity to see how large animals react to the setting sun. Granby Zoo, east of Montreal, will be closed to the public so researchers can observe those precious dark minutes.
“We are going to see if the animals go towards their night habitats, if some of them are going to vocalize,” said Chelsey Paquette, conservation coordinator with the zoo. She expects some animals to be louder than others.
“Japanese macaques are probably going a little crazy,” suggested Paquette. “We think they could vocalize, huddle in the group together. They could really look at the sun, or lack of it.”
Many other zoos along the eclipse path are also preparing for studies. Granby Zoo is contacting a zoo in Texas to compare data.
Longer term disruption
Regardless of any initial changes in behavior, experts say the eclipse is a momentary break in patterns — and that these species face many longer-term dangers.
Huber said climate change, being as rapid as it is, includes [layered] with development, pesticide use and habitat destruction, and we’re seeing massive changes out there.”
SEE | 1 in 5 migratory species at risk of extinction: UN:
A recent UN report says that climate change is affecting migratory species, as is habitat loss and overexploitation.
Huber says studying animals during an eclipse is an “intellectual exercise.”
“These little things that are happening are nothing compared to some of the large-scale things that we as humans are doing,” he said.
