Fall on the Prairie

Late in September the days grow shorter and the nights get longer, indicating that fall is fast approaching. Snowfall in early October is not uncommon in the northern parts of the prairie and freezing temperatures team up with the wind to remind the fauna and flora that it is time to disperse, migrate, go dormant or fatten up because winter is right around the corner.

Young black-footed ferrets, called kits, are adult-sized by early fall and many have left their mother’s territory. This is a very crucial time for a ferret kit because it will have to strike out to find new, unoccupied territory while being exposed to predators and other hazards. Despite being less than 2 feet long (including the tail), a black-footed ferret can move quickly across a landscape and cover relatively large distances. Prairie Wildlife Research has documented moves of 13+ miles by a ferret over a short time period. One of the great mysteries is how a ferret knows what direction to travel and how far to travel before it will encounter another prairie dog colony, if they know at all. They might just be that bold and curious to strike out into the unknown.

Burrowing owls in South Dakota usually leave by the first week in October to begin their migration south. Cooler temperatures translate into fewer insects to forage on. Prairie dog colonies, spread across the landscape, serve as stopping points for many migrating birds. Raptors like bald eagles appear temporarily on prairie dog colonies because of the great hunting opportunity as they move through. Large flocks of ducks, geese and songbirds can be seen and before you know it….they are gone.

Most prairie grasses turn yellow and brown in late summer but some of the forbs and other vegetation remain green until the fall. As the weather sets in the plants begin to go dormant and the contrasting earthtones of yellows, reds and browns are set against the blue sky. Typically the fall months see some rainfall (or snow) on the prairie which replenishes the soil moisture and gives many plants that last little bit of help to endure the harsh winter.

With the breeding season over, pronghorn gather into large bands and, in some places, even begin a long migration. Sometimes the pronghorn migration is made more difficult by man-made objects that these animals never had before. For instance, have you ever seen a pronghorn jump a fence? They have the physical capabilities to do so but rarely will you see it jump. Pronghorn will crawl under a fence but if the bottom wire on the fence is too low then it will create problems. Often they will run along a fenceline until an appropriate place to cross is found and then, one by one, they will duck under the fence.

Prairie dogs spend much of the fall getting fat, gorging themselves on grasses and forbs to put on extra layers. White-tailed prairie dogs, found in Wyoming, Utah and Colorado, become inactive and begin hibernation in the fall. The most common species of prairie dog, the black-tailed, does not typically hibernate and is generally active in the fall. After molting the prairie dogs have a heavier fur layer to withstand cold temperatures and wind but they can always retreat to the relative warmth and security of the burrow. Fall is also a time for burrow maintenance including building up the mound, gathering new nesting materials and patrolling the territorial boundaries.

By mid-December the prairie has changed quite a bit from the summer with far fewer birds, dormant vegetation, fluffier mammals and scatterings of snow on the ground. The flora and fauna are now prepared to deal with the harsh realities of winter.