Chipmunks are cute little animals that live across North America and in parts of Asia. When it comes to the sleep habits of these animals, we need first to ask, are chipmunks nocturnal or diurnal? Because of their eyesight, chipmunks are most active during the day and sleep at night, which makes them diurnal animals. This article explores the sleep behavior of chipmunks. It discusses why they are suitable for being primarily active during the day.
Sleep Behavior of Diurnal Chipmunks
Chipmunks are diurnal mammals. These animals sleep after sunset and do not leave their burrows until sunrise the following day. They then wake up at dawn and are most active in the mornings. You will likely find chipmunks foraging for food in the bushes or forest floor before taking it to their burrows. Although chipmunks are most active in the morning, they are also active in the afternoons. Sometimes, chipmunks will take naps during the day between their foraging trips.
The main reason chipmunks are diurnal is because their eyes are adapted to see during the day. Chipmunks have excellent vision and great response times during daylight. Because of this, they can protect themselves and escape from predators with ease. If chipmunks were nocturnal, they would not enjoy these advantages, easily becoming the target of predators.
Chipmunks Have Terrible Night Vision
Chipmunks are diurnal because of their weak night vision. During the daytime, they have excellent eyesight because their eye structure allows the entry of plenty of light. With so much light entering their eyes, their visibility during the day is ideal. The opposite is also true. So, chipmunks avoid going out during the dark hours of the night because this behavior will place them at significant risk of death because they cannot see predators.
Chipmunks, like other living creatures, use their eyes for multiple purposes. They use their eyes to find food, read the landscape, detect danger, and more. Because chipmunks’ instincts are astute, they can readily read environmental signs of threat and take action to avoid threats through rapid response times. For example, if a chipmunk sees the shadow of a bird of prey, their brains identify it as a sign of danger. They will immediately find shelter and protection.
Chipmunks also have a broader view of their environment because of the position of their eyes. These small mammals have eyes on the sides of their heads. In contrast, people’s eyes are in front of their heads. This positioning means that chipmunks enjoy a more expansive viewing range than the 90-degree angle that people experience.
Exploring the Chipmunks Eye Structure
No matter how diverse mammals are, they share certain similarities in their eye structures. For instance, all mammalian eyes comprise an iris and pupil that allows light to enter the eye. This light travels through the lens until it reaches the retina at the back of the eye.
The retina consists of rods and cones, enabling the animal to distinguish between certain frequencies, with some seeing specific colors and others not being able to discern colors. Despite apparent differences, the eye structure helps animals see better during the day or night because the information picked up by the retina then travels to the optic nerve and enters the brain.
Rods and Cones
Eye rods and cones function differently. Rods help the eye detect objects in areas with low light, while cones support seeing well in settings with brighter light. Rods detect motion and send basic visual information to the brain. In contrast, eye cones help to see finer movements and details and send more complex visual information back to the brain. Cones are also responsible for color detection.
More Cones Than Rods
Chipmunks have better vision during the day because their eyes have fewer rods than cones, and their eyes are also small with rounded pupils. This type of eye does not function well at night. Nocturnal animals often have large eyes with slit pupils. Because of this structural difference, nocturnal animals’ eyes are well adapted for nighttime vision and filtering light, depending on the time of day. Additionally, some nocturnal animals have a light-boosting mechanism in their eyes, known as the tapetum.
Where Do Chipmunks Sleep?
There are 25 species of chipmunk, and most of these live in North America. Chipmunks prefer to build their nests in trees, fallen logs, holes under houses, and even under the ground. These animals build burrows where they sleep, store food, and escape predators.
Chipmunks construct large tunnels with different entrances and rooms when building underground shelters. Some shelters can be 30 feet long and three feet deep. Their burrows have two levels, with the first being a shallow tunnel and the second being a deeper tunnel with multiple rooms. The second level consists of their sleeping area, food storage spaces, and bathroom.
Once they dig the burrow, the chipmunk will furnish its sleeping area with plant matter, like grass and leaves. These animals are intelligent and often build their dens on a slope to allow water to drain. They will also remove any fresh dirt from the openings of their burrows so that predators cannot find them.
Do Chipmunks Hibernate?
It depends on their location. Suppose chipmunks live in an environment with cold winters. In that case, they will hibernate, but this behavior is not as many people imagine. Chipmunks will hibernate for periods and interrupt their hibernation to wake up and eat the food they’ve foraged, like nuts and seeds. In environments where chipmunks do hibernate, they do so in late October and end this inactivity during March or April in the northern hemisphere.
Preparing for Hibernation
Chipmunks prepare for winter and hibernation by foraging and gathering food. Some species of chipmunk store the food in their burrows while others do not. These animals are not opportunistic feeders and prefer to eat foods like seeds, nuts, grains, fruits, worms, and types of fungi.
When chipmunks enter hibernation, their body temperature decreases from 94 degrees to the temperature of their burrow. Their heart rate will also reduce from 350 beats per minute and can go as low as four beats per minute. Slowing of the heartbeat keeps their body temperature down and supports waking to eat once every few days. Because of this, chipmunks do not easily rouse from their hibernation slumber.
Not All Chipmunks Hibernate
But not all chipmunks hibernate. Chipmunks living in warmer climates or areas where the temperatures rise towards the end of winter will not hibernate. A researcher from Fordham University, Craig Hank, found that non-hibernating chipmunks have a lower survival rate. Hank’s findings also show that the chipmunks that do not often hibernate do not survive till the end of winter. In contrast, chipmunks that do hibernate have an 87% survival rate.
When Are Chipmunks Most Active?
Chipmunks forage during the early morning and late afternoon. This time is when these mammals are most active. These animals forage in trees but prefer to feed on the ground. Sometimes, chipmunks will return to their burrows and sleep throughout the day to prepare themselves for their activity in the late afternoon.
How Long Do Chipmunks Sleep?
Outside of the wintertime, chipmunks need to sleep 15 hours each day. Chipmunks are highly active animals awake, so they need as much sleep as possible to reenergize for their foraging trips. Chipmunks will also take naps during the day if they have been busy to prepare for the continuation of their foraging before they sleep at night. When chipmunks hibernate, they do so for up to a few days. Their body temperature and heart rate drastically decrease, which allows them to hibernate and survive for this long. They will then wake up and adjust their bodily functions before eating and using the bathroom.
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