Dan Collins, a migratory game bird biologist for the U.S. Fish and Wildlife Service, said he wanted to “peel back the curtain” and give people a view into the work federal biologists do with sandhill cranes.

In the 1970s, there were only 25 mating pairs of Rocky Mountain greater sandhill cranes in Colorado, and though that number has rebounded to between 250 and 300, according to the Colorado Crane Conservation Coalition, the Rocky Mountain greater sandhill crane remains a Tier 1 protected species. 

Before a crowded room on Saturday, Sept. 3 — the third day of the Yampa Valley Crane Festival — Collins gave a keynote presentation about the methods biologists use to survey and monitor sandhill cranes, what their research entails and plans for future studies of this iconic species. 

---

---

Collins has tracked and marked nearly 1,000 cranes. He showed a brief video of biologists using “rocket nets,” which are angled to shoot netting several feet above grounded cranes and safely ensnare them before they take flight.

“Then you send graduate students running out,” Collins said.

---

---

The biologists wrap bands around the cranes’ feet that track their location and take morphological measurements to determine whether they are greater or lesser sandhill cranes.

Since their research began in December 2012, Collins and his colleagues have banded 952 cranes across eight Western states, primarily in New Mexico. Collins said he receives an update whenever a bird pings a cellphone network, and so far the trackers have identified more than 3 million GPS locations of cranes. 

Collins said his research team continues to make new discoveries about the migration patterns of sandhill cranes, and the maps showing their habitats will keep evolving over time.

The sandhill cranes’ diet and migratory trends are the most central aspects of Collins’ research.

One of the biggest challenges of preserving sandhill cranes is to ensure they have plenty to eat without relying on food grown on private property. 

The chili farms in New Mexico, for example, have attracted the attention of many sandhill cranes, much to the dismay of the property owners.

“So corn was put on the ground and is now used as a management tool to keep these birds off the local producers,” Collins said.

An important task for researchers, according to Collins, is to identify when are where it’s best to supply food. Using a process called “stable isotope analysis,” biologists analyze tissue from sandhill cranes to determine their diet, and combined with GPS tracking data, researchers can determine when and where sandhill cranes are searching for the specific food they need.  

Collins and his team have determined that sandhill cranes look for corn especially from mid-December to mid-February. Collins said their research is also helping prevent oversupplying the birds’ diets.

“We figured out that we didn’t need 3.1 million pounds of corn,” Collins said. “We need about 2 million pounds of corn, so that reduces the footprint.”

Collins provided models that demonstrate how effective the supplemental feed programs have been. Using GPS data of banded sandhill cranes in the Middle Rio Grande Valley, where an estimated 80% of Rocky Mountain sandhill cranes spend the winter, Collins showed a graph suggesting the birds have a strong preference for public lands with feed, instead of private.

“That tells us that the supplemental feed program is working,” Collins said. “It’s keeping those birds off of those local producers.”

Collins finished his talk by expressing a desire to partner with more private landowners to coordinate strategies for future conservation efforts.

“We need to engage these folks,” Collins said. “They’re conservation-minded. “We just we need to learn how to talk with them. I will end it with that.”

To reach Spencer Powell, call 970-871-4229 or email him at spowell@SteamboatPilot.com