Why do nocturnal animals stay up late?

When the sun goes down, the forest doesn’t sleep. There’s a whole night shift of creatures that use the cover of darkness to survive. For both predators and prey, nighttime has advantages and disadvantages. Early mammals, for example, likely evolved for living in the dark because most dinosaurs were active during the day. But, while moving in the darkness may help you escape the notice of a scary diurnal T. rex, you may miss out on a meal that is visually prominent, such as a brightly coloured fruit. These selective pressures likely helped develop an incredible sense of smell that isn’t dependent on light: you don’t see the fruit, but you can still find it with your nose. We as daytime mammals can’t smell our way to our next meal (unless the neighbour is barbecueing again), but nocturnal animals of all shapes and sizes often use smell or hearing or touch as their major sensory organs. This allows the forest to be active 24/7 and means there is a crew change as the daytime team gives way to the night shift one: hawks to owls, red squirrels to flying squirrels, butterflies to moths.

Flying squirrels

While many have a love/hate relationship with most squirrels, flying squirrels, with their big, adorable black eyes, seem to create less anger than other squirrel species. If you are lucky enough to find one, the awws at its cuteness will quickly turn to oohs if it decides to glide away. 

Flying squirrels can glide more than 20 m from tree trunk to tree trunk using their patagium, a fold of loose skin along their sides that stretches out when they launch into the air. While it’s not true sustained flight like with birds and bats—which flap their wings to attain upward motion—it certainly works for squirrels making a quick getaway from a predator. 

It can be hard to see these amazing aeronautic feats at night. Most sightings are quick glances as one glides across an opening and is silhouetted against a darkening sky. Winter bird feeders can help with observations, as these gliders will visit them for a late night snack. If a flying squirrel becomes tolerant of your presence, you might be able to get a good look at its parachute-like skin flaps.

Nocturnal advantage: By foraging at night, our two flying squirrel species (northerns and southerns) avoid direct competition with diurnal eastern gray and red squirrels as well as eastern chipmunks. But, while they do avoid daytime hunters such as northern goshawks, red-tailed hawks, and broad-winged hawks, they are a favourite prey of barred owls.

Meet the flying squirrel

Barred owls

Photo by Canadiantimber/Shutterstock

An owl’s eerie sounds are as part of the cottage at night as ghost stories, s’mores, and campfires. All owls are chock full of adaptations for a nighttime existence: large eyes; soft, silent flight; and, of course, loud, far-carrying sounds for contacting each other. Most importantly, though, who needs lots of light when you have the best hearing of any animal ever tested? Many owl species have asymmetrical ear openings, with one slightly higher than the other, allowing them to hear not only in a horizontal plane (like us) but also in a vertical plane. To understand how this works, think about keeping your head still and facing forward but with your eyes shut. A bee flies by you and you can hear it go from left to right. An owl, though, would be able to tell that the bee was moving slightly upwards as it flew by. They can pinpoint the location of noise-making prey so well that they can catch it without even seeing it.

Probably the most commonly heard cottage owl, the barred owl (above), makes the distinctive and easily imitated Who cooks for you? Who cooks for you all? call to mark their territory and to keep the love alive between a pair. In fact, if two barred owls are feeling especially amorous, their regular call pattern will break into a loud, eclectic series of laughs and hoots that sound like a troop of clowns that have become a bit tipsy at a far-off campsite. They will sometimes call during daylight hours, especially on overcast days.

Nocturnal advantage: Lots of rodents are out after dark, and owls have evolved to take advantage of this buck-toothed smorgasbord. Plus, by hunting at night, owls also avoid competing with faster hawks, eagles, and falcons.

See 11 cottage country owls


Photo by Melinda Fawer/Shutterstock

Butterflies get all the attention, but moths are really where it’s at. For one thing, there are way more species of moths in Canada (more than 5,000) than butterflies (around 300). For another, we are used to thinking of moths as drab, and while some are, there are many with a wild side. In the fall, one group to watch for are the underwings. These moths are masters of camouflage when resting on a tree trunk, but when they open their upper wings, they reveal flashes of pinks, yellows, oranges, and reds on their hindwings—which is where they get their name. One theory to explain these bright colours is that they could be used to startle a potential predator. Imagine a bird getting close to finding a camouflaged moth and then the moth flashes its colourful hindwings as it takes flight—this may startle the bird long enough for the moth to escape and hide somewhere else. It could also work the other way around, where a predator notices a flying underwing with its bright colours but when the moth lands it “disappears.” Because the predator is focussed on finding the pink or orange, it misses out on discovering the now-camouflaged insect.

 Whatever the reason, having concealed colourful hindwings is a successful strategy—there are more than 100 moth species in this group in North America.

Nocturnal advantage: By being active at night, moths avoid most insect-eating birds, which are usually diurnal. Moths also can collect nectar from flowers at night without competing with many other pollinators. In fact, some flowers only open at night to take advantage of pollinating moths.

Wolves, coyotes, and foxes

Photo by Thea Boyd

The dog-days of summer may be behind us, but are you ready for the three-dog nights of autumn? We have three members of the canine family that you might hear during fall evenings. 

Let’s start with the biggest: the wolf. While howling does occur throughout the year, both eastern (or Algonquin) wolves and timber wolves can be quite vocal in fall when it plays a role in their family dynamics. Howling lets pack members know where its members are and also lets one pack proclaim its territory to other wolves. But the howling also appears to be a bonding activity for the pack in the later summer and fall when adults start to leave their pups for the evening and go out to hunt. Pups at this stage are too big to stay in their dens but too little to go along, so they are left at “rendezvous sites,” where they have to wait until the parents return with food. A lot of social interactions happen at these sites, and when the adults make their deep drawn-out howls, you may hear their chorus interspersed with the coyote-like yapping and yipping of the pups. Once they are old enough to hunt with the pack, the rendezvous sites are no longer used and howling is less frequent.

No wolves nearby? There are likely coyotes, which really are just a small species of wolf (and, thus, deserve the same wow-factor). They make lots of noise at night—including yipping that sounds similar to wolf puppies, but can be heard all year. Wolves or coyotes (or both) will often respond to people’s attempts to wolf call. Even other sounds, like the whistle of a train, can get them going; I’ve heard up to three separate coyote packs call back at once from different directions after a train goes by.

Our third cottage canine is the red fox. This little guy is in the dog family, but isn’t closely related to wolves, coyotes, or domestic dogs. Unlike those bigger cousins, red foxes don’t really howl. Their most common sound is a screaming bark. Imagine saying the word “wow” but with a high-pitched, screechy voice. This noise, often repeated a few times, appears to be an identification call that foxes use for distant communication. Like dogs, foxes make the same sounds for different meanings, depending on the situation. As the autumn turns to winter and as we enter the fox’s breeding season, another call may be heard: a drawn-out scream made by females in heat. Heard in the depths of winter, it can certainly put a chill up one’s spine.

Nocturnal advantage: With their keen noses, these canine hunters are able to detect and surprise their prey before being noticed. Also, communicating is easier for packs at night, when the winds tend to die down, and their howls and barks can carry great distances across the dark landscape. 

This story was originally published as “Wild Night Out” in the October 2022 issue of Cottage Life. Wolf Lake, Ont., cottager Chris Earley is the interpretive biologist and education coordinator at the Arboretum at the University of Guelph.

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