Signs of Spring: March Means Migration

In Wisconsin the long, icy nights of February (24 out of 28 nights featured jaw-dropping “lows”, from single digits down to minus 22) tried to follow us into March – lows of minus 7, minus 13, and minus 22 all occurred within the first 6 days of the new month. But now the low temperatures are as warm or warmer than the high temperatures recorded in February. Hello, Spring!

Saying ‘goodbye’ to the ice blasts of Winter 2014.

Perhaps nothing says early spring more than bird migration, and the birders among us are keenly aware of little signs from common birds right outside their windows. For evidence I offer a post from Operation Migration’s Field Journal where Heather Ray describes what she’s seeing near the OM office in Port Perry, Ontario; and check out the observations from 28 commenters to the post, chiming in from Texas, Florida, New Jersey, Ohio, Georgia and all over the Upper Midwest.

Then there is the first sighting of sandhill cranes returning to Wisconsin, posted March 10th, by the International Crane Foundation on their Facebook page. When I read about it, I wondered instantly how normal it is to have cranes of any species, returning to Wisconsin this early – especially with the harsh winter we’ve had.

There’s little cause to worry, I learned from the ICF’s Long-Term Sandhill Crane Project Manager, Andrew Gossens. It’s not that unusual to see some cranes when there is still snow cover. “We generally see cranes in our long-term study when there is still a fair amount of snow on the ground,” Gossens wrote, adding that in general cranes are pretty cold-hardy birds. “Cranes can survive in snow-covered environments just fine as long as they can find food to eat and water to drink and roost in.”

A sandhill crane, pictured in an International Crane Foundation file photo. The sandhills are much more numerous in Wisconsin than the rare and endangered whooping crane.

Gossens speculates that the early arriving sandhills are mostly breeding territorial adults. He said:

“The reason for some birds’ early arrival has to do with the fact that these birds are most likely returning breeding adults who want to get back to reclaim their territories before other birds can claim them for their own. Territories (places where breeding pairs nest and raise young) are a limiting factor for these birds and if a pair cannot claim a territory early, they will not be able to breed and raise young.”

And what about the much more rare – only 100 or so – whooping cranes that will soon be returning here? Through Gossens I learned that Eva Szyszkoski, the Tracking Field Manager for the Whooping Crane Eastern Partnership,  says that whooping crane arrivals usually coincide with general warming trends, water bodies thawing, and south winds favorable for a northward migration. That said, whooping cranes, too have been known to arrive back in Wisconsin when the marshes and ponds of their nesting grounds are still completely frozen.

Whooping Cranes have sometimes returned to Wisconsin when ponds like this are still frozen solid. (Photo, courtesy of International Crane foundation.)

WCEP just recently published its periodic status update for the Eastern Migratory Population – the whooping cranes that nest here in Wisconsin. Dated December 16, 2013 – February 28, 2014, the WCEP Update says these birds were distributed across Florida, Alabama, Georgia, Kentucky, Tennessee, Illinois and Indiana.