For the Birds Radio Program: Sandhill Cranes Facing the Cold
Today Laura Erickson talks about the difficulties Sandhill Cranes faced during this cold spring. 4:13
This has been such a difficult winter and spring for northland owls that it’s hard to imagine that the season’s been equally hard in other areas of the country. But odd Gulf Stream patterns have brought frigid temperatures down further south than normal. When I went to Nebraska the first weekend of March, it was ten below, and had been even colder the days before I arrived. The Platte River had been open for weeks beginning in February, but the sudden arctic blast froze the river again, after most of the Sandhill Cranes had already arrived.
The first I realized that this was a unique situation was when I saw my first cranes flying in. Cranes fly with their outstretched feet trailing behind. They have such little blood flow in their legs and feet that this doesn’t normally affect their body temperature at all, even when the weather’s cold. But this cold exceeded anything cranes are adapted to, so every bird I saw tucked its feet inside its belly feathers in flight. I’d never seen anything like this, and most of the birders I’ve talked to, including those that have watched cranes for years, hadn’t either. Cranes in flight are beautifully balanced, their long, skinny neck outstretched fore and their long, skinny legs sticking out aft. These poor birds looked stunted and odd, like they’d been sliced with a machete. They tucked in their legs the moment they took off, and kept them tucked in until inches before hitting the grounds.
If the cranes in flight looked awkward and weird, they were at least more comfortable in the air than in the river. Most of the Platte was frozen, and the flowing open water carried big chunks of ice, which would pummel and abraid any crane legs that stood in it. So at day’s end, the birds had a terrible time finding safe places to sleep for the night. Although they normally settle in to the river around sunset, during this awful period many of them were still flying back and forth over the river searching for a safe bed of water well after dark. And in the darkness, may of them smacked into the power lines strung across the river.
There are two sets of wires at the Rowe Sanctuary where tens of thousands of cranes sleep. These wires have been regular death traps for the cranes, and in these conditions they were worse than ever. Birds don’t see straight lines–in studies in the Great Plains, 68 percent of ducks didn’t adjust their flight when approaching power lines in daylight, and in the dark, these poor cranes didn’t have a chance. Seventeen dead ones were found under one set of wires. The leg of one and the wing of another had been ripped off by the impact. One crippled crane huddled on the ice. It would eventually freeze or starve unless an eagle or coyote got it first. Each dead or crippled bird represents a double loss, because its bereaved mate won’t accept a new mate until about a year of mourning.
Another set of wires had been fitted with plastic spirals designed to be visible to birds. Only one dead bird was found beneath those. The Audubon sanctuary paid a third of the cost to put those spirals on, and the pattern of this season’s deaths prove that they work. But the power company won’t cover any of the costs to fit the other wires with spirals, so the sanctuary is trying to raise the entire cost themselves. Nebraskans apparently don’t appreciate the national treasure that runs through their midst. The sanctuary hasn’t been able to raise even a hundred dollars so far, and they need $3,000. So for now, cranes will continue to bonk into wires over the Platte River, an awfully high price to pay for electricity.