By BEN NEARY
NMWF Conservation Director
It’s common for the harsh squawks of greater sandhill cranes to ring through the air in New Mexico’s Middle Rio Grande Valley at this time of year. They often sound oddly close, even when it takes careful examination to find their passing chevron formations impossibly high in the sky.
The greater sandhill crane is a big bird, with adults standing some 4 feet tall with a wingspan of over 6-feet-6. They’re primarily gray with long, pointy beaks and red crowns.
New Mexico provides important winter habitat for these bruisers, with most wintering along the Rio Grande from Albuquerque to the Bosque del Apache, south of Socorro. Some turn up in southwestern New Mexico and elsewhere.
Dan Collins, migratory game bird biologist with the U.S. Fish and WIldlife Service in Albuquerque, tracks sandhill cranes and other migratory birds in the state.
Collins will be the featured speaker at the New Mexico Wildlife Federation’s January 2024 Wildlife Wednesday event. His presentation will start at 5:30 p.m., Jan. 10,, at Marble Brewery’s Northeast Heights Taproom, at 9904 Montgomery Blvd., NE, Albuquerque. The event is free.
Sandhill cranes are among the world’s oldest bird species, with fossil records showing they’ve been largely unchanged for millions of years.
“I call them modern-day pterodactyls, because they have been on this planet for a very, very long time,” Collins said. “And the fact that they’ve been able to adapt to a multitude of changes over miillions of years is extraordinary.”
The survival of the sandhill crane for so long is all the more remarkable given that they are slow to reach reproductive age and don’t produce a lot of young, The birds often don’t breed until their five years old. Nesting females typically produce two eggs, but commonly only one chick will survive.
The anatomy of the sandhill crane’s bronchial tube helps them make their distinct noise, which can be heard for miles under certain conditions.
“Anatomically, the bronchial tube comes out of where the lungs sit into sort of the chest cavity,” Collins said. “So that bronchial tube helps them make that gurgling sound. It’s just set up differently, and allows them to make those noises, and allows that sound to carry a lot further than say, a duck or a goose.”
The sandhill cranes in New Mexico come from two different populations, Collins said. “Primarily the cranes that are on the east side of the state are going to be from the Mid-continent population,” he said. “And the birds that overwinter here in the Middle Rio Grande and southwest portion of the state are going to be from the Rocky Mountain population.”
There’s some overlap of the different populations, but Middle Rio Grande valley is considered the most important over-wintering area for the Rocky Mountain population, Collins said.
The Mid-continent population, made up primarily of lesser sandhill cranes, is well over 1 million birds, Collins said. He said the Rocky Mountain population is only about 27,000 birds, of which about 80 percent overwinters in the Middle Rio Grande Valley.
The sandhill crane population along the Middle Rio Grande is stable to slightly increasing, Collins said. The population objective is between 17,000 to 21,000 birds and the current three-year running average is about 23,000.
The Rocky Mountain population breeds and summers in Colorado, Utah, Wyoming, Idaho and Montana with only a few birds making it as far north as the southeastern portion of British Columbia and Southern Alberta, Collins said. The Mid-continent birds nest farther north.
The U.S. Fish and WIldlife Service tracks sandhill crane migrations. It has banded over 1,000 sandhill cranes and has placed GPS units on about 150. Trapping cranes to fit them with bands or GPS units to track migration and population numbers has its challenges, Collins said.
Trapping cranes to fit them with bands or GPS units to track migration and population numbers has its challenges, he said.
“When we trap, I basically tell people to watch your eyes and watch your chest because of that big, long sword on the end of their face, as well as their talons, claws, whatever you want to call them,” Collins said. “They can tear up skin really quickly…. They can be pretty ornery, and they’re very territorial.”
New Mexico allows hunting for sandhill cranes. The New Mexico Department of Game and Fish issues limited permits for birds from the Rocky Mountain population. The longterm average harvest of birds in the Rocky Mountain population is 325 per season, from 1988 through 2022. The highest harvest was 710 birds in 2022. Many hunters regard sandhill crane as among the finest meat of all.
Collins said his presentation will include information on how the USFWS makes its harvest management decisions.
Cranes aren’t picky eaters, and have a particular fondness for corn. “In a perfect world, they’re going to be omnivores,” Collins said. “I’ve seen them eat field mice, I’ve seen them eat other little critters that they can get, that they just happen to come upon, they’ll eat. They eat aquatic invertebrates, other seed sources.”