Sandhill and whooping cranes, the only species of cranes in North America, have faced extinction.
Sandhill crane numbers declined in the 1930s due to hunting and habitat loss, according to George Archibald, co-founder and senior conservationist at the International Crane Foundation. Wisconsin was down to 25-30 pairs.
Now, approximately 1.25 million sandhill cranes make an annual spring migration stop on a narrow stretch in Nebraska’s Big Bend reach of the Platte River, roughly from Lexington to east of Grand Island. It’s about the halfway point on their 2,500-mile migration from wintering grounds in southeast Texas to breeding areas in northern Canada, Alaska and Siberia, and the narrowest point in the Central Flyway.
Their several-week stay allows them to rest and add up to 20% to their body weight before continuing their journey.
Whooping cranes follow a similar spring migration route, but may arrive a few weeks later. They often stay only a few days along the Platte River and at other wetlands.
Archibald said whooping crane numbers had dropped to 22 — 15 migrating and six nonmigrating in Louisiana — by 1941. He estimated there were around 75 when the International Crane Foundation was established in 1973.
Although the number is 834 today, whoopers remain the rarest (and tallest) cranes.
Approximately 600 are in the wild.The rest are in captive groups, including ones in ICF projects to establish a new migration route between Wisconsin and Florida, and re-establish the first nonmigrating flock in Louisiana in more than 80 years.
“I remember celebrating when we hit 100 and 200 whooping cranes, so we knew we were on the upswing,” Archibald recalled. He added that the pattern of growth probably has continued because whooping cranes have so far avoided a catastrophic event.
MEASURING UP
There are obvious differences between gray sandhill cranes and taller white whooping cranes with black wingtips, but they are different in other ways.
Whooping cranes
- Height: 5 feet
- Wingspan: Up to 8 feet
- Weight: 11-16 pounds
- Lifespan in the wild: 22-30 years
- Eggs: Usually 1-3
- Mating: For life
- Migration: More than 2,500 miles (southeast Texas to northern Canada) as individuals, pairs, family groups and small flocks of 5-10 birds. They primarily fly in daytime at high altitudes and up to 500 miles per flight.
Sandhill cranes
- Height: 3-4 feet
- Wingspan: 5-6 feet
- Weight: 6-14 pounds
- Lifespan: 20 years
- Eggs: 1-2
- Mating: For life
- Migration: Up to 5,000 miles (mostly southeast Texas to northern Canada, Alaska and Siberia) at 40-50 mph
Hurricane Harvey in 2017, which hit southeast Texas where whooping and sandhill cranes spend the winter, was a close call.
Bird flu is a constant concern for all crane species. Archibald said two whoopers died of bird flu last fall in Saskatchewan.
A recent migration routine change is the growing number of sandhill cranes overwintering in Nebraska. According to Crane Trust data, that happened only three times prior to 2011 — in 1964, 1977 and 1994 — and involved a few thousand cranes.
Overwintering has been observed in eight of the last 10 years, with the crane numbers growing each year.
This recent winter, Crane Trust staff counted approximately 30,000 cranes in the Platte’s 7 miles between Highway 281 and the Alda bridge, the most so far.
They said reasons for the increase include climate change, milder winters, open water, available food and the loss of wetlands in Texas, Oklahoma and Kansas.
