UPSIDE-DOWN EFFECT OF TOTAL ECLIPSE
Elementary school closures, outreach activities, gatherings for observation… The solar eclipse on April 8 will turn our Monday afternoons upside down, but it will also have a major impact on other living organisms. Let’s see how animals react to solar eclipses!
For hundreds of years, the impact of eclipses on animal behavior has aroused scientific curiosity. Animals are particularly sensitive to eclipses, since they regulate their daily activities according to the alternation of light and darkness. What’s more, the variation in the number of hours of light over the course of the year modulates behaviors such as reproduction, moulting or migration. [1]
grey heron, image from Pixabay
How can 2-3 minutes of total darkness accompanied by a 10-15 minute drop in temperature modulate animal behavior? Animals are used to a fairly constant number of hours of sunlight from one day to the next. The eclipse cuts the sunshine period drastically and at a highly unusual hour. In Montreal and Sherbrooke, the eclipse will be total at 3:26 pm and 3:27 pm respectively. What’s more, it will last 3.26 minutes in the Eastern Townships, but only 1.27 minutes in Montreal [2]. Curiously, some animals don’t seem to be affected, such as cows [1], zebras, elands, crocodiles, warthogs, lions and herons [3]. On the other hand, many others are greatly disturbed by this change.
Hippos, image from Pixabay
Diurnal animals
Diurnal animals are active during the day and rest at night. They use the sunny period to carry out their daily tasks (moving around, feeding, reproducing…). During an eclipse, the sudden darkness informs these animals that it’s time to rest.
During the 2001 eclipse in Zimbabwe, impalas showed nervous and alert behavior in the wake of the eclipse, although their reaction during the event was not observed. The baboons stopped feeding and moved to their resting place during the eclipse, as did several birds . At the end of the eclipse, the baboons returned to eating as if nothing had happened, but not all the bird species observed. Birds that had been singing before the eclipse fell silent during the darkness and started up again when the light returned. Day squirrels stayed in their holes and didn’t come out after the eclipse, even though they normally feed at this time of day. Butterflies landed immediately after the partial eclipse and did not fly again. [3] It has also been observed that bees returnto the hive during an eclipse, and much more quickly than usual [4]. Rohus fish have also been shown to reduce their foraging due to the drop in water temperature during an eclipse [5]. Spiders, for their part, began to unravel their webs during the eclipse and then rebuilt them [6].
Bees returning to the hive, image from Pixabay
Nocturnal animals
Nocturnal species use the dark period of the day to become active, and the light period to rest. In contrast to diurnal animals, nocturnal animals are awakened by the short period of daylight in their sleep.
During the 2001 eclipse, hippos woke up and dispersed in the water during the interlude of darkness. When daylight returned, they remained stressed for the rest of my day. For the owls, this little period of darkness stimulated their hooting. [3] Some bats showed activation during the period of darkness during the 1999 eclipse in Mexico. Some went outside, while others stayed put [7].
Bats, image from Pixabay
Considering all these different behaviors during a total eclipse of the sun, it’s worth asking which elements dictate a change in behavior or not. A better understanding of the impact of eclipses on animals also leads us to a better understanding of their behavior in non-natural environments with controlled lighting.
Don’t hesitate to let us know if you observe any particular behaviours in the wild or in your pets during the eclipse on April 8!
[1] De Henrike, L. et McLeish, T. (2024). Eclipse and Revelation : Total Solar Eclipses in Science, History, Literature, and the Arts. Oxford University Press, Incorporated. p.358. https://ebookcentral.proquest.com/lib/usherbrookemgh-ebooks/reader.action?docID=7388610&ppg=308
[2] Gouvernement du Canada. (2024). Éclipse solaire totale du https://www.asc-csa.gc.ca/fra/astronomie/eclipses/eclipse-solaire-totale.asp
[3] Murdin, P. (2001). Effects of the 2001 total solar eclipse on African wildlif. Astronomy & Geophysics, Volume 42, Issue 4, August 2001, Page 4.4, https://doi.org/10.1046/j.1468-4004.2001.0420044.4.x
[4] Waiker, P., Baral, S., Kennedy, A. et al. Foraging and homing behavior of honey bees (Apis mellifera) during a total solar eclipse. Sci Nat 106, 4 (2019). https://doi.org/10.1007/s00114-018-1597-2
[5] Jennings, S., Bustamante, R.H., Collins, K. and Mallinson, J. (1998), Reef fish behaviour during a total solar eclipse at Pinta Island, Galápagos. Journal of Fish Biology, 53: 683-686. https://doi-org.ezproxy.usherbrooke.ca/10.1111/j.1095-8649.1998.tb01010.x
[6] W. Uetz, G. et al. (1994). Behavior of Colonial Orb-weaving Spiders during a Solar Eclipse. Volume 96, Issue 1, Pages 24. https://onlinelibrary.wiley.com/doi/10.1111/j.1439-0310.1994.tb00878.x
[7] Sánchez, O., Vargas, J. A., & López-Forment, W. (1999). Observations of Bats during a Total Solar Eclipse in Mexico. The Southwestern Naturalist, 44(1), 112–115. http://www.jstor.org/stable/30055414
