The maple syrup you use to pour on your pancakes probably comes from a bottle, but one resourceful rodent goes straight to the source when it wants a taste of something sweet.
Maple syrup was first gathered by the indigenous people of North America, most commonly among Native American tribes that lived in what is now recognized as eastern Canada and the northeastern United States. An Iroquois myth explains that Native Americans initially learned how to collect sap from maple trees by watching the actions of red squirrels. According to folklore, an Iroquois youth observed a red squirrel cutting into tree bark with its teeth and later returning to lick the sap; the young Iroquois boy followed the squirrel’s lead and tried the same technique by cutting into the tree bark with a knife, thus discovering the maple tree’s sugary secret.
In the early 1990s, a scientist named Bernd Heinrich observed and reported on the sugaring behavior of red squirrels in an article published in the Journal of Mammalogy. In his study, Heinrich watched as the red squirrels bit into the tree bark of maple trees, creating a “single pair of … chisel-like grooves that punctured the tree to the sap-bearing xylem.” The squirrels did not immediately lick up any sap. Instead, they waited until water had evaporated from the sap and concentrated its sugar content, typically 24 hours after biting the trees, during the early morning hours before the sap began to run anew.
Other forest animals that eat sap, such as sapsuckers, a type of bird, do not discriminate between sap sources and will eat sap from a variety of trees and other plants. In contrast, red squirrels actively seek out sugar maple trees to tap for sugar. Heinrich also discovered that red squirrels only tap sugar maple trees when the xylem sap contains the highest sugar concentrations. The flow of sap in maple trees is caused by large changes in temperature, and typically occurs after leaves drop from the trees in autumn, on unusually warm days in winter, and in early spring before budding occurs. Heinrich found that these time periods coincided with the greatest amount of sugaring behavior in red squirrels. Squirrel bite marks on sugar maples were most common in late winter, early spring, and late fall. During the summer months, Heinrich observed no new bite marks on any trees.
Unlike some other rodent species, red squirrels do not hibernate during the winter months. Instead, in the late summer and early fall months, the squirrels begin to collect nuts and pinecones, which they store in burrows found within their territories. By the time sugaring season comes around, the squirrels’ food stores are typically quite low. The concentrated sugar content found in evaporated maple sap provides the squirrels with a much-needed energy boost.