Sunday, June 15, 2008

Flooding Bird Nests

The massive floods in Iowa this spring are forcing animals in their path to move to higher ground. In particular, flooding has disrupted nesting for any bird species that breed along riverbanks.

What's of particular concern is how rare species of birds, reptiles and amphibians will fare, he said.

Also, there are many bird species in Iowa that winter in Central and South America, returning to Iowa in late May or early June to nest near rivers and streams, Pease said. Those birds usually nest once a year. If their nests have been swept away by the floods, "then that's it for the year," he said.

"If we get too many years in a row of this, we'll certainly see population declines," Pease said.

Harr said wildlife is resilient, and many songbirds will renest two or three times this year, and pheasants may be able to renest later this summer.

But the floods will probably take most of the nests of sandhill cranes this year, Harr said. The birds, which nest just once a year, nest along some of the state's eastern rivers.

If spring conditions are good next year, it's expected that the birds will return to nest, Harr said.
The loss of an entire year's worth of nestlings is troubling but probably will not depress the bird population too much. What is more concerning is that these types of hundred-year events could happen with more frequency. One of the many predicted consequences for climate change is an increase in the frequency and intensity of heavy storms such as the ones currently flooding the Midwest. With these types of events happening more often, we would probably start to see substantial losses in riparian bird populations.