Sandhill Cranes
A poster-bird for migration.
The Sandhill Crane Fest in Monte Vista, Colorado, recently posted:
So, it’s a good time to repost my Sandhill Cranes write-up from last March. Enjoy! If you can, it’s definitely worth the road trip to see this for yourself! - Karen
I could still hear cranes in my sleep. Twenty-seven thousand Sandhill crane calls have embedded their distinctive sound deep into my psyche.
My daughter and I spent two days at the various viewpoints at the Monte Vista, Colorado, National Wildlife Refuge. Our entire time was spent watching, and hearing, thousands of Sandhill Cranes that have returned to their Spring migration rest stop on their way back north. Four-foot tall cranes filled the sky and covered the ground as they moved from roosting sites, for overnight resting/sleeping, to feeding sites in the farm fields, and loafing sites for leisure and mating dance rituals. Often, they collected in smaller groups of several dozen moving together, we would watch wave after wave of these crane groups arriving at one of the sites. Other times, nearly the entire flock would rise in a murmuration-like cloud so clamorous it drowns out all other sounds or even talking to the person next to you. (Sound on for the video! Loudest at the end.)
The cranes’ seasonal return to places like Monte Vista, Colorado, or Kearney, Nebraska, has been repeated since long before we humans knew to watch for it and create festivals around it. For hundreds of thousands of years, untold generations of cranes have been returning with their offspring each year back to their nesting sites, teaching the next generation the places to rest on the journey north (or south in the Fall). Their migration takes them from wintering in South Texas, Northern Mexico, and Florida, to back up around the Arctic Circle in Canada and Alaska for summer breeding. Travel days can cover up to 500 miles, staying aloft at 6,000 to 13,000 feet and higher. We have seen them many times flying high over the Foothills, and their distinctive honking is heard well before we spot them. Their stop-overs mid-country will last for 30–40 days before they move on once again. By mid-April, the cranes and their honks (distinctive from Canadian Geese honks) will leave Colorado once again.
The Sandhill Crane has become a ‘poster bird’ for migration in North America. Their size and noise create enough havoc for us to take notice with fascination. They are the very visible envoys of a broader activity that is happening at the same time. Worldwide, birds, butterflies, and even moths will take to the air soon to return from warmer wintering areas to summer breeding sites long-established in their evolutionary patterns. Similar patterns are happening in the oceans and on land as well, but we’ll stick to the birds for this short essay.
As much as we think it is seasonal cues such as food resources running low, sun angles, longer or shorter days, or star positions to assume birds know when it’s time to migrate, the whole picture is still less clear. When the combination of these cues comes together, birds begin to exhibit Zugunruhe,[1] a German word for ‘migration anxiety’. They become restless and prepare for their travel days. When it comes time to take off, their compasses guide them to return to birthplaces and the resting areas their parents brought them to previously. But how do they find their way?
Humans figured out using the magnetic poles for navigation in the 1400s, this was 2000 years after magnetism was first discovered in 600bc. Humans need tools to tell us about the magnetic poles to make use of the consistent properties to find our way. Many creatures, however, have a ‘magnetoreception’ sense, an internal biological compass. From moths to whales, the ‘6th sense’ of magnetoreception is an internal guide they follow.
While we can attribute sight to the cell receptors in our eyes and smell to the design of our nasal passages, the sense of magnetoreception is not one that can be dissected to discover. Magnetic fields pass right through our biological matter, so we have yet to learn what picks up the sense. Several theories are being tested, from the mineral magnetite, to electromagnetic induction like sharks have, to quantum physics. Research is ongoing, and many scientists are eager for answers. Suffice it to say that the birds and many other creatures know where to go and how to get there.
Getting there is a wild ride also. Flying at altitudes of 6,000 to over a staggering 30,000 feet (airliner cruising altitude), migrating birds of all sizes get on the move in the spring in flocks so thick they are spotted on radar. Back in the 19th century, migrating passenger pigeons would darken the sky for days as billions of birds were on the move. When they would land to rest, so many pigeons filled the trees that strong branches broke under the weight.
Often flying during the night, guided by starlight and by their internal compasses, birds can cover thousands of miles. Many types of birds can make the flights non-stop and can even ‘sleep on the wing’, alternately resting a half of their brain at a time. There’s a lot of ongoing study on this to understand it better. Some make stop-overs like the Sandhill Cranes; others will travel over 90 hours at a time to reach their destination, likely forgoing sleep. Each migration is a marvel of their adaptations to arrive to their instinctive destinations.
Migration is an exhausting endeavor and a vulnerable time for birds. As much as they follow their internal senses to migrate, a lot of external elements come into play as well. Weather patterns, storms, airplanes, city lights, pollution, tall buildings, glass windows, and predators make this a perilous journey. Since many of these obstacles are human caused, we can be a part of making conscientious decisions to reduce these dangers. Lights are the number one way we can do our part. Birdcast.com will post updates on high migration nights. Here’s Park County, Colorado. You can plug in your own location as well. Cornell Labs, which runs Birdcast.com will send out Migration alerts on their Facebook page. Turning off extra lights will help with bird navigation. (And gives you a better night sky, chimes in my proofreading astronomy student.)
As we move into this Spring, get those binoculars ready to watch your property for birds you might not see regularly. We had a visit of 75 or so Bohemian Wax Wings last April, and I love spotting a Western Tanager at the feeder. When you see a new bird, you can look it up with the Merlin app and report the sighting on eBird or iNaturalist, which are monitored by many scientists to see where migrating birds are passing through. It’s a bit of citizen science and your participation would be greatly appreciated. Let me know who visits you!
Thank you for stopping by. My hope is always to point to what is around us and highlight its purpose on the planet, its role in the broader ecology, and the interactions with humanity. The more we know, the more we will care about, and will desire to keep around for future generations. We are all a part of the grand ecology of planet earth.
If you’ve benefited from these posts, I would be immensely grateful for supporting the research and writing time spent with a paid subscription. - Karen
📷 All photos are credited: The Abert Essays unless otherwise noted.
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Sources:
- https://en.wikipedia.org/wiki/List_of_birds_by_flight_heights
- An Immense World: How Animal Senses Reveal the Hidden Realms Around Us, by Ed Young. Link is public library
- Vesper Flights, by Helen McDonald. Link is public library.
- What It’s Like to be a Bird, by David Sibley. Link is Amazon
- https://naturesdepths.com/magnetic-migration/
- https://www.scientificamerican.com/article/how-migrating-birds-use-quantum-effects-to-navigate/
- https://www.allaboutbirds.org/guide/Sandhill_Crane/overview#
- https://www.fws.gov/sites/default/files/documents/2023%20Crane%20Viewing%20Brochure.pdf
- https://www.alamosa.org/905-faq-the-sandhill-crane-migration-in-the-slv
- https://www.audubon.org/field-guide/bird/sandhill-crane
- https://en.wikipedia.org/wiki/Bird_migration
- https://www.fws.gov/story/migration-its-risky-journey

[1] “When the time comes for birds to migrate, they become visibly restless. Even in captivity, they’ll hop, flit, and flutter. These frantic movements are known as Zugunruhe—a German word that means “migration anxiety.””
— An Immense World: How Animal Senses Reveal the Hidden Realms Around Us by Ed Yong. https://a.co/53QrZ3s
We have them year-round here in Florida, but I’ve never seen them in large groups like that. Would love to see them migrate! I can only imagine the spectacle!