Natural Notes: Animals of the Night

Are you a night owl?  If you're an Illinois wildlife species, than chances are, yes!  However, many animals besides owls are active at night.  In fact, the majority of wildlife species in Illinois are hunting, gathering mates, establishing territories, and moving about during the nighttime hours!

A daytime walk on a trail through a forest preserve might yield some common wildlife sightings such as gray squirrels (Sciurus carolinensis) or sparrows.  Most animals that people see around Illinois are active during the day, or  diurnal.  Humans are a great example of a diurnal animal.   Other animals though are most active active at different times of the day (figure 1).  Late in the afternoon or early in the day, many folks encounter white-tailed deer (Odocoileus virginianus).  Deer are a great example of a wildlife species that is crepuscular, or active at dawn or dusk.

Figure 1:  In Illinois, most wildlife species are more active at certain times of the day. 

For those brave enough to venture out during the nighttime, the woods can feel quiet and eerie.  You can be rest-assured though that it is otherwise, as the forests at night are filled with some rarely seen but common nocturnal wildlife species that are out and about in the middle of the night:

The Southern Flying Squirrel (Glaucomys volans) (see figure 2) is actually a more common species than the notorious gray squirrel but is rarely seen due to its nocturnal behavior.  Despite its name, flying squirrels do not actually fly but instead glide from tree to tree using a flap of skin on their underside known as a patagium (see figure 3).  Southern flying squirrels have enlarged eyes for easier night vision and can glide as much as 20 feet from one tree to another.

Figure 2:  The Southern Flying Squirrel is a common yet rarely encountered nocturnal animal.  Photo credits:  Paul J. Dako.  

Figure 3:  Flying Squirrels do not actually fly but use their patagium to glide from tree to tree.  

Owls are the "hawks of the night" and fill the niche of their daytime counterparts, hawks, as birds of prey.  Like hawks, owls have sharp talons and beaks and prey most frequently small rodents.  However, owls are uniquely adapted to hunting at night as they have soft layers of downy feathers on their wings and even on their feet that buffers the "swooshing" sound that most birds produce when they flap their wings.  This gives owls the ability of silent flight, which prevents them from scaring their prey items.  Their large eyes allow maximum light exposure resulting in keen vision as they stalk their midnight prey.

Most bat species in Illinois migrate south for the winter, or if caves are nearby as they are in Southern Illinois, will overwinter there.  Bats use echolocation to navigate at night and to detect food sources.  Bats are the only class of mammals that has wings and can fly (figure 4).  Never pick up a bat that is on the ground as it could have rabies.  Generally, bats that are healthy and are actively flying around do not have rabies.  Bats are often misunderstood animals, but they play an important role in the ecosystem, eating nuisance insects like mosquitoes and keeping gnat and no-see-um populations in check.  In Illinois, all bat species are obligate insectivores (they eat only insects). Bats are difficult to identify down to species but one of the most common bat species in northern Illinois is the Little Brown Bat (Myotis lucifugus).

Figure 4:  Little Brown Bat.  Photo Credits:
U. S. Fish & Wildlife Service.  

Skunks are not often an appreciated animal as their defense mechanism is both strange and unpleasant.  Skunks have scent glands underneath their tail that can shoot out a putrid smelling liquid that's bad enough to make a fox hurl!  Skunks can spray at distances as much as 50 feet or more when threatened.  Skunks are usually active on mild nights but are less active (dormant) during cold or inclement weather. 
 The most common skunk species encountered in Illinois is the Striped Skunk (Memphitus memphitus) (see figure 5).   Although they are known to ravage garbage cans, they can also play a beneficial role in suburban landscapes by eating grubs, beetle larvae, and other nuisance animals.

Figure 5:  Striped skunk.  Photo credits:  River Trail Nature Center,
Forest Preserves of Cook County.  

Racoons are known as "bandits of the night" and this title is well-deserved. They have become well suited to living in urban areas and are often caught red-pawed digging through a dumpster in densely populated places like downtown Chicago and other urban areas. Racoons are very closely related to the much more charismatic Red Panda (Ailurus fulgens) native to Southwest Asia.  
 

Coyotes (Canus latrans) are closely related to the wolf (C. lupis), but are much smaller in size and are not commonly found in packs (see figure 6).  Coyotes were originally found in the Rocky Mountains and points westward but are now found throughout the United States.  Coyotes are adapting well to urban environments and are now a common wildlife species in the Greater Chicago Area.   Coyotes are a keen animal, and have been observed to wait for traffic to clear before crossing the street.  Coyotes are most active in the night, but in the winter it’s possible to spot a coyote during the day when temperatures are a little more mild.  

Figure 6:  A coyote catches a small rodent along the Des Plaines River in Cook County, Illinois.  Photo credits:  Jerry Aterre/Forest Preserves of Cook County.  

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Of course, there are many other animals active at night in Illinois, but most of us never see any of them as humans are diurnal by nature.  Now that you know a little something about some our nighttime critters, perhaps you'll get lucky and spot some of these amazing animals of the night.