Do flamingos nap during a solar eclipse? Phoenix Zoo wildlife reveal varied reactions

A little past 11 a.m. on Monday, the moon covered more than half of the sun as the solar eclipse neared its peak. The trees' shadows projected lights on the ground at the Phoenix Zoo in the shape of little crescent moons.

Most of the animals behaved normally.

But while the zoo was more crowded than other Mondays, there was a distinct calm. Most of the birds stopped chirping and singing when the sunlight dimmed.

That morning started with an overcast sky and weak sunlight, but as it progressed, the clouds dissipated, and the animals enjoyed the sun's warmth.

The flamingos had bickered with each other as they normally do, according to senior bird keeper Kyle Waites.

"They are pretty feisty with all the breeding going on," Waites said. "They bicker a lot because the pairs are trying to find a little spot to build their nest, and then, they like to build them really close to each other, but they also don't like other ones being that close."

Demonstrating the knowledge zookeepers can share with the public, Waites explained in depth the typical behavior of flamingos and other birds.

Zookeepers usually work with animals during the day, and they are most familiar with their behaviors during that time.

"I've seen them a couple of times at night when we've had nighttime events like Zoo Lights," Waites said. "It is interesting seeing the birds at night because you don't really know where they sleep or things like that. You can have signs, but unless you put up cameras, you don't really know."

Then around 11:30 a.m., when the moon had covered the sun as much as it would in Phoenix, making it seem like a smile, almost all of the flamingos stood on one of their long legs, hid their heads in their feathers and began napping.

Once the sunlight shone on everything again, the flamingos awoke, eating, bathing in their pond, and pecking their beaks with each other.

Changes in animal behavior during partial eclipses are unexpected

Arizona zoos did not anticipate significant animal reactions because, as with an eclipse in 2017, the state was not under the path of totality, and the moon covered only about 65% of the sun.

Drew Foster, director of Living Collections at the Phoenix Zoo, recalls not noticing any significant changes in the animals' behavior that August morning in 2017. Still, he remembers the air cooling down while the sunlight remained dim.

Decreases in temperature and light are two factors most associated with changes in animal behavior during total eclipses.

"Animals' behavior is driven by what they're experiencing in the environment. And with a full eclipse, the environment is changing rather drastically, going from a sunny day, perhaps, to quite dark," Foster said.

Transitions in their conduct might mimic behavior shifts related to the end of the day, when diurnal animals may prepare to go to sleep, he said, "but then again, the eclipse passes, and the environment changes again. So you see that behavior shift back to the normal daytime behavior."

Still, determining the reason for certain animal behaviors is more challenging than it sounds.

Centuries of studying animal behavior changes during eclipses

Historical records offer a glimpse into the enduring curiosity surrounding this topic.

In 1239, Italian scholar Ristoro D'Arezzo documented how "animals and birds became frightened" in his description of a total solar eclipse. Similarly, in 1560, German astronomer Christoph Clavius described how birds fell to the ground during another eclipse, overwhelmed by the sudden darkness.

Advancements in biological sciences have led to numerous studies. Although most research has been conducted on animals during total eclipses, and much remains to be documented about partial eclipses, the discoveries made thus far are edifying, they say.

Some remarkable observations analyzing animals reacting to eclipses include:

• 1984: Chimpanzees facing the eclipse and gesturing in the same direction

• 1991: Spiders taking down webs in the darkness of totality

• 1998: Birds foraging over the water before the eclipse, as they usually did at sunset

• 2001: Hippos and impalas acting nervous because of the disruption in their routines

• 2017: Some 75% of observed species in a zoo engaging in their evening or nighttime behaviors. The other most frequent response was apparent anxiety.

• 2018: Bees cease flying during complete darkness at totality.

In 1991, scientists observed desert cicadas during a partial eclipse and noticed a long stop in their calling.

In Tucson, black-and-white ruffed lemurs raise a ruckus

Netzin and Dieter Steklis observed the animals' reaction to the eclipse at the Reid Park Zoo in Tucson.

The couple are faculty members in the School of Animal and Comparative Biomedical Sciences and co-directors of the Human-Animal Interaction Research Initiative (HAIRI) at the University of Arizona.

Both have extensive experience investigating primates and working in animal conservation. They lived in Africa for a while studying wild chimpanzees, "and then we spent about 15 years working with mountain gorillas," Dieter Steklis said.

The couple have converged on professional similarities.

"Both of us are fundamentally motivated by our interests and deep love for animals and their protection," he said.

Their strategy to watch animals' behavioral changes was to separate at the zoo so they could cover more species.

"I was watching the giraffes because there are some published reports that show giraffes, both in the wild and in at least one zoo, during a full eclipse, running around, kind of going crazy," Dieter Steklis said, "but they weren't fazed by it at all."

The long-necked animals didn't react differently to the eclipse, but in another part of the zoo, Netzin Steklis heard a loud ruckus, and immediately recognized the sound of a primate.

The black-and-white ruffed lemurs use vocalizations to communicate. The calls alert their group of threats and help locate food.

Even after noticing only that sign in a single species, both agreed that there is still so much left to understand.

"This eclipse is shining a light on the amazing diversity of animal perceptive abilities and sparking curiosity," Netzin Steklis said.

The scientists said there is still much to learn about animals' reactions to natural events and their responses to human-caused environmental effects, such as air or light pollution.

Trilce Estrada Olvera writes about environmental issues for The Arizona Republic and azcentral. Send comments and story tips to trilce.estradaolvera@arizonarepublic.com.

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This article originally appeared on Arizona Republic: Animal behavior during eclipse: insights from a day at the zoo