Dan Collins, a migratory bird biologist for the US Fish and Wildlife Service, said he wanted to “raise the curtain” and give people a glimpse of the work federal biologists do with sandhill cranes.
In the 1970s, there were only 25 mating pairs of Rocky Mountain sandhill cranes in Colorado, and while that number has rebounded to between 250 and 300, according to the Colorado Crane Conservation Coalition, the Rocky Mountain Greater Sandhill Crane remains a level 1 species protection.
In front of a packed room on Saturday, September 3 – the third day of the Yampa Valley Crane Festival – Collins gave a keynote presentation on the methods biologists use to investigate and monitor sandhill cranes, what their research involves and plans for future studies of this iconic species. .
Collins tracked and tagged nearly 1,000 cranes. He showed a brief video of biologists using “rocket nets”, which are angled to shoot nets several feet above ground cranes and trap them safely before they take flight.
“Then you send graduate students missing out,” Collins said.
Biologists wrap bands around the feet of cranes that track their location and take morphological measurements to determine whether they are larger or smaller sandhill cranes.
Since their research began in December 2012, Collins and his colleagues have banded 952 cranes in eight western states, mostly in New Mexico. Collins said he receives an update every time a bird pings a cell phone network, and so far trackers have identified more than 3 million GPS locations of cranes.
Collins said his research team continues to make new discoveries about sandhill crane migration patterns, and maps showing their habitats will continue to evolve over time.
The diet and migratory patterns of sandhill cranes are the most central aspects of Collins’ research.
One of the biggest challenges in preserving sandhill cranes is ensuring they have plenty to eat without relying on food grown on private property.
Chili farms in New Mexico, for example, have caught the attention of many sandhill cranes, much to the dismay of owners.
“So the corn was put on the ground and is now being used as a management tool to keep these birds away from local growers,” Collins said.
An important task for researchers, according to Collins, is to identify when it is best to provide food. Using a process called “stable isotope analysis”, biologists analyze the tissues of sandhill cranes to determine their diets and, combined with GPS tracking data, researchers can determine when and where sandhill cranes are looking for the specific food they need.
Collins and his team have determined that sandhill cranes look for corn in particular from mid-December to mid-February. Collins said their research also helps prevent overfeeding of bird diets.
“We figured out we didn’t need 3.1 million pounds of corn,” Collins said. “We need about 2 million pounds of corn, which reduces the footprint.”
Collins provided models that demonstrate the effectiveness of supplementary feeding programs. Using GPS data from banded sandhill cranes in the middle Rio Grande Valley, where about 80% of Rocky Mountain sandhill cranes overwinter, Collins showed a graph suggesting the birds have a strong preference for public lands. with food, rather than private.
“That tells us the supplemental feeding program is working,” Collins said. “It keeps these birds away from these local producers.”
Collins ended his speech by expressing a desire to partner with more private landowners to coordinate strategies for future conservation efforts.
“We have to hire these people,” Collins said. “They are conservation conscious. “We just need to learn to talk to them. I’ll finish with this.
To reach Spencer Powell, call 970-871-4229 or email him at [email protected]