Here in Park County, change is in the air. For those willing to slow down and perceive them, the subtle signs of Spring approaching have been present for weeks.
The change in temperatures is just part of it. Several passerine species (song birds), have started to show up, and with them they have brought the realization that spring is near.
It will not be long before fishermen are stopping on the shore of South Park’s reservoirs to cast a line rather than walking on top of ice to their favorite ice fishing spots. Soon after, the birth pulse for the majority of wildlife will occur and spring will be in full swing with newborns entering the world.
Many wildlife species around the world use migration as a means of following seasonal and geographic changes in weather and food availability. Migration is present across the animal kingdom in mammals, fish, birds, reptiles and even some insect species.
When migration is brought up, many folks think of the massive wildebeest migrations in Africa that conjure up visions of frantic river crossings with crocodiles lying in wait. Migration in mammals is quite diverse with species ranging from bats to whales and caribou, to seals taking part in their own annual pilgrimages. Migration is everywhere.
With the vast expanse of the planet’s oceans at their disposal, some marine fish species make gruelling migrations. The Atlantic bluefin tuna makes remarkable migratory movements that span the width of the Atlantic Ocean, from the coasts of South Carolina to northern Ireland.
Birds are not to be outdone, with some species covering tens of thousands of miles each year. The world champion is the Arctic tern which travels from pole to pole and back; literally from one end of earth to the other and back.
Through the use of GPS, some terns have been documented traveling nearly 60,000 miles on this journey while chasing the sun.
Insect migrations are some of the most fascinating. The Monarch butterfly, an animal that weighs less than a coin, travels from parts of Canada to central Mexico. Yet the distance pales in comparison to the fact that the individual has never been to its final destination and neither its parents nor grandparents had ever been there before.
Due to the phenomenon of inter-generational migration, it is returning to a destination where its great-grandparents left.
Migration is not an exotic adaptation that only occurs in far-flung animals. Many of the species right here in South Park migrate.
South Park’s elk herd is migratory, with individuals from at least eight different Game Management Units settling into South Park each winter. South Park also lays claim to one of the highest elevation pronghorn populations in the world.
South Park’s pronghorn are highly migratory, because they are living at the species’ temperature and elevation tolerance threshold. Every winter the pronghorn from around Park County move to the southeast side of South Park, near the base of Wilkerson Pass.
This is fairly obvious for those of you that routinely travel U.S. Highway 24 during the winter months. The herd uses the same routes to access this area year after year. After the spring thaw, the herd will again disperse about the region.
In August, Governor Polis signed an executive order directing the Department of Natural Resources and Division of Transportation to ensure the ongoing conservation of wildlife winter range and migration corridors.
In order to maintain healthy wildlife populations, the routes that these species use should be kept in mind in plans for future developments. Residential and commercial development can negatively affect, if not altogether cut off, crucial migration routes for our native wildlife.
Therefore, care must be taken to ensure that the routes these species have used for thousands of years remain available. People feeding wildlife can also alter migratory behaviors and put wildlife at risk. Lastly, it’s important to remind ourselves to be extra vigilant while driving during migration seasons as vehicle-wildlife collisions rise during those times of year.