When the Moon completely covers the Sun this Wednesday, at certain points in Spain the day will transform for a few moments into a kind of twilight. For some animals, this sudden alteration of light can activate behaviors normally associated with the end of the day.
The scientific observations made during previous eclipses have documented birds that modify their songs, crickets that begin to make sounds, animals that seek shelter, and nocturnal species that increase their activity. The response, however, depends on each species, the place, and the environmental conditions.
Birds may interpret the eclipse as dusk
Birds are among the animals in which the most changes have been observed during solar eclipses.
The sudden drop in brightness can provoke behaviors similar to those of sunset. Some species reduce or modify their songs, seek places to perch, or temporarily change their activity. When the light returns, they can regain their usual behavior.
There is, however, no universal reaction. The accumulated observations show different responses depending on the species and the circumstances of the eclipse.
Crickets, frogs, and other animals may "believe" that night has arrived
The change can be particularly striking among animals whose activity is closely related to light and darkness cycles.
Crickets have begun to emit their characteristic sounds during previous eclipses. Changes have also been observed in frogs and other animals with crepuscular or nocturnal habits.
Specifically, NASA promoted during the 2024 American eclipse the citizen science project Eclipse Soundscapes, dedicated to studying through recordings how animals reacted —with special attention to crickets— to the arrival of that "false night."
And bats? They don't always come out when it gets dark due to the eclipse
One of the most intuitive images would be to think that bats come out of their shelters when the sky suddenly darkens. Research shows a reality that is quite more complex.
During the total eclipse of 2024, for example, it was not observed that millions of Mexican free-tailed bats left a cave in Texas during totality. Previous studies had also not detected clear changes in some populations.
The researchers point out that factors such as the duration of the totality, the temperature, the species, or the place where the animal rests can determine the response. Bats located in dark caves, for example, receive much fewer signals of the external change in brightness than those that rest in places exposed to light.
Can the eclipse affect dogs and cats?
In the case of dogs and cats, the eclipse does not pose a special danger by itself. Veterinarian Sonia Lois Peña explains to RTVE that these animals do not feel the human curiosity to contemplate the phenomenon and normally have no reason to stay looking directly at the Sun.
That does not mean that their eyes are immune. One should not force a pet to look at the Sun, as direct exposure can cause eye damage, according to the veterinarian.
There may also be temporary changes in behavior. Animals that are especially sensitive could react to the unexpected darkness, crowds, or, above all, to the behavior of the people around them.
Therefore, for domestic dogs and cats, the recommendation is simple: maintain a normal routine and not try to make them observe the eclipse.
Other animals may begin their nighttime routines
There are also historical and scientific observations of striking behaviors in other species.
During previous eclipses, it has been observed that some cows return to the barns, while certain insects begin their activity and some species that normally activate at dusk respond to the sudden decrease in brightness.
Even web-weaving spiders have been studied. There are observations that suggest that some may dismantle their webs during an eclipse, a behavior that researchers have tried to document systematically.
Not all animals will react to the eclipse
The available evidence requires avoiding a generalization: it cannot be stated that all animals will behave in a certain way this August 12.
Total eclipses are infrequent events in the same place, and that makes it difficult to obtain large amounts of comparable data. Researchers have also found that individuals of the same animal category can respond differently depending on their environment.
What is documented is that the sudden decrease in light and the environmental changes associated with totality can temporarily alter the signals that certain species use to regulate their daily activity. For a few minutes, while millions of people look at the sky, some birds, insects, and nocturnal animals may interpret that the day has ended prematurely.