Spring is here! The equinox occurred on the twentieth. Animals are starting to become more active now, even the porcupines.
Porcupines can be found over much of Canada, the northern United States, and Rocky Mountains. Here in North Dakota they may be observed in the Turtle Mountains, Killdeer Mountains, Pembina Hills, and around Devils Lake and the Mouse, Missouri, and Red rivers. Plus, they are surprisingly common in brushy areas in the badlands of the Little Missouri River.
Porcupines do not hibernate. They have spent their winter feeding on the bark and twigs of trees and shrubs. The nutritional value of that winter diet is poor, and does not meet their minimum nutritional requirements. If all goes well for the porcupines their fat reserves helped get them through the winter in good shape.
That is particularly important for the pregnant females. Porcupines have a gestation period of 210 days, which is comparatively long for a mammal of that size. Females will give birth to a single offspring, around early May, and the young will stay with their mother for the first six months. By the way, the quills are soft and quite flexible until after birth, but harden about an hour afterwards.
As spring commences, however, and the buds on the trees and shrubs begin to swell and break dormancy, the porcupines will go on a sort of feeding binge on this fresh and nutritious food supply. Of course all the trees and shrubs do not develop simultaneously, so the porcupines will have several options upon which to dine.
In addition to the importance of high energy and protein content in their diet, the porcupines seem to crave salt during the spring. As some of you probably know, porcupines have a thing for salt. The need for salt varies throughout the year and is related to diet and physiological status of the animal. For example, female porcupines need a lot of salt when lactating.
By the way, needing supplemental salt in the diet is not unique to porcupines. For example, large ungulates such as cattle, deer, elk, and bighorn sheep also need salt. The animals that need to supplement their diets with salt are herbivores. Plant material generally does not provide enough salt to meet the animal’s needs. Animal tissue generally does. So a predator’s diet typically contains enough salt to meet their needs.
Chuck Lura
Natural North Dakota is supported by NDSU Central Grasslands Research Extension Center and Dakota College at Bottineau, and by the members of Prairie Public. Thanks to Sunny 101.9 in Bottineau for their recording services.
