Ask a Naturalist: Why do some animals migrate while others stay put?

This article was written by Elizabeth Poulson, Minneapolis Parks and Recreation Board Naturalist, North Mississippi Regional Park

Each year, large groups of animals move from one place to another. This movement, better known as migration, is a concept with which many are familiar. Some of the most astonishing feats of endurance are demonstrated by long-distance migrants of the animal world. These large-scale movements of animals across landscapes have fascinated humans for millennia.

The spectacle of animal migration has been intertwined with human history dating back to the Stone Age. Early hunter-gatherers recorded images of animals that could possibly have served as records for areas rich with hunting opportunities as well as the influence of those animals in their culture. Nomadic groups of people were dependent on particular populations of animals for large parts of their livelihood and would often move across a landscape as the animal moved. For example, the American Bison played a pivotal role in American Plains Indian culture as a source of food, medicine, clothing and spirituality.

Often, when we think of migration, large flocks of birds may come to mind first. Birds are one of the most commonly noticed groups of animals moving from one place to another during different times of the year. Other well-known migrants include salmon returning from the ocean to their natal inland streams, and caribou moving across the Arctic tundra.

Perhaps the most well-known insect migrant is the Monarch butterfly. It is the only butterfly known to make a two-way journey similar to avian migrants. Monarchs complete a 2,500 mile trip from Canada to Mexico and back again. No single individual completes the whole round trip, as the length of it exceeds their lifespan. Instead there is a kind of intergenerational relay as individuals make their journey.

Migration occurs in all animal groups on Earth, including humans, for one reason or another. Most often though, the heart of migration boils down to one instinct: survival. Migration allows a species to adapt to meet its basic needs and also prevents the long-term depletion of food sources in one area. These periodic movements mean each individual has a better chance of finding enough to eat as well as better opportunities for breeding.

For animals that have been observed migrating each year for many years, it also begs the question of how they know when to begin their seasonal movements and, furthermore, how they find their way.

Unlike humans, wild animals can’t track changes throughout the year with a hand-held calendar. Instead, they use environmental cues such as changes in light, food supply or temperature to trigger their migration. Some also rely completely on internal cues such fat reserves and instinct to help guide them.

Additionally, one of the most visible guides migrants will use is the topography of the local landscape. The Mississippi Flyway is an obvious route that generally follows the Mississippi River from northern Minnesota to the Gulf of Mexico. The river itself helps guide birds in addition to providing good sources of water, food and cover as they make their journeys. About 40 percent of migrating birds and waterfowl take advantage of this route due to the lack of navigational obstacles such as mountains or ridges of hills.

In Minnesota there are many opportunities to view migrating birds, due in large part to the amount of water bodies our state has. The Mississippi Flyway, as mentioned above, which runs along the Mississippi River is one of those places in the heart of Minneapolis where you can view many species of birds making their seasonal migrations. To learn more about migration and the Mississippi River Flyway, join a naturalist at the Kroening Interpretive Center for Watchful Wednesdays every other week (Nov. 6 and 20) from 8:30-10 a.m.

November Public Programs–Free unless otherwise noted. November 2 – Bird Watching: Mississippi Flyway, 8:30-10 a.m.; November 2 – Trail Trekkers: Adults 10-11 a.m. and families 10:15-11:15 a.m.; November 7  – Campfire Mingle, 6-8 p.m. ages 18+; November 9 – Hike: River in the City, 10:30-11:30 a.m.; November 10  – Nature Tots: Floating & Flying Ducks 3-4 p.m. ages 2-6, $5/child; November 14 – Homeschool Day: Decomposer Exposure, 1-3 p.m., $5/child; November 16 – Outdoors: Tracks & Scat, 2-3:30 p.m.; November 23 – Nature Art: Cornucopias, 1:30-3 p.m.; and November 29 – Nature’s Black Friday Fun, 11-3 p.m.


Find registration for these programs and more at or call 612-370-4844 for more details. Do you have a question about nature in your own backyard? Then send it our way by emailing and it could appear in a future article. Like us on Facebook to stay in the loop about what is happening at your park.