Out of the 15-crane species around the world, Sandhill cranes have the largest population and are the most wide-ranging species due to their vast migratory routes.
Migration is a fundamental aspect to avian ecology as it allows them to move between breeding sites and make the most of the favorable conditions in the different seasons. This has a positive effect on their health and reproductive success.
Amazingly, like many other bird species, Sandhill cranes have long continental flyover routes where they cover up to 400 miles a day. Along these vast routes they have stopover sites to rest and refuel in.
Sandhill cranes are noted to have both a spring and fall migratory period. Normally, the cranes migrate south between September and November and then return between February and April.
But, not all Sandhill crane subspecies migrate as some do not need to escape their region to avoid a harsh winter. Instead, the Siberia, Canada and Alaska subspecies all migrate as they are not equipped and stand a better chance of survival in the south during winter months.
Winter: At the beginning of the year, Sandhill cranes usually locate themselves in Southern USA and very near the border of Mexico. Why? Warmth. Specifically, the cranes can be spotted in Texas, California and Florida in late winter months.
Spring: Between March and April 80% of the cranes in North America are said to use a 75-mile stretch of Nebraska’s Platte River to migrate north. While doing so the birds are often spotted across states such as Colorado, New Mexico, Nebraska, Montana, Illinois and Indiana at their resting sites.
Summer: By the time summer arrives, the cranes can be found in the northern most regions of the U.S., Canada and Alaska. About one third of the Sandhill crane species nests and breeds in the boreal forest of Canada and Alaska with some even spotted as far north as Siberia.
Fall: During the autumnal months, the cranes start to make the long journey back south again.
Do They Migrate in Flocks?
Sandhill cranes are known to migrate in smaller family groups or populations. But, whilst in flight groups are said to merge together making an extremely large flock made up of thousands upon thousands of birds.
These groups emerge throughout their journey when they make individual stopovers to refuel before continuing on their long journey again.
So, we know when Sandhill cranes start migrating due to the season but their movement is more specific than that.
The cranes have six different populations due to their differences in where they nest in different seasons and over winter.
This population consists of cranes that nest in the Pacific Northwest such as Washington, Oregon and northern California. They spend winter months in southern California and migrate back in February and March.
This population has similar nesting and winter ranges to the Central Valley population but some of its birds breed further north into southern Alaska. Birds will migrate from Alaska in late August to reach their southern wintering grounds.
This population is known to nest in western states such as Montana, Idaho and Colorado and migrate to New Mexico and Arizona between August and October.
Lower Colorado River Valley:
Consisting of Nevada and south west Idaho, the lower Colorado river valley population has similar migratory patterns to the Rocky Mountain population. The only difference is that they leave their nesting grounds in September and return again in March.
This population located across eastern states of the US begins migrating as soon as September continuing into January if mild weather pursues. They fledge their wintering grounds and head north in February until April.
The largest population of Sandhill’s to migrate, this movement of cranes usually begins in August to north-west Minnesota, Canada and Alaska.
Do All Sandhill Cranes Migrate?
Short answer, no. Populations that do migrate are the lesser, greater and Canadian Sandhill crane. These cranes nest in countries such as Siberia, Canada, Alaska and states situated in the northern US and are not able to stand their harsh winter months.
Therefore, as mentioned earlier, they migrate during the fall to their wintering grounds in either Florida, Texas, New Mexico, California and even Mexico itself.
Do They Migrate During the Night?
Sandhill’s are not known to be in flight during the night. AS soon as the sun sets the birds are said to be in their stop over resting places with their beaks on the ground foraging for food.
However, if they are close to their end destination that has their annual nesting place they have been known to keep flying until they reach their known habitat.
So, it’s clear that Sandhill cranes migrate and have a variety of fly ways all across the US. Something that began out of evolutionary need and survival for the birds has become a bird watcher’s spectacle.
Watching the cranes land in wetlands and agricultural fields and forage before flying off in groups again is a highlight for bird watchers and avian scientists across America.
But, not every sub-species migrates and this is due to their home environment. If they originate from the colder northern regions then they will migrate away in winter but some species don’t feel the need when originating from Southern, sunnier, states.
We still have so much to learn about this wonderful species and how they have and will continue to roam the earth for thousands of years.