At first glance the duck population numbers released by Ducks Unlimited earlier this summer are alarming.
Mallard numbers are down 11 percent from last year. Wigeon numbers decreased by 10 percent and green-wing teal are down 16 percent and redheads 13 percent.
On the other hand, the population of each of those species are still comfortably above their long-term average.
Tom Moorman, chief scientist at Ducks Unlimited, said the long-term numbers are the most important.
“There are a lot of nuances in the data; you can’t get too balled up over year-to-year change,” he said. “Annual variation happens. What we don’t want to see, for instance, is a consecutive series of years where the change from year to year is negative.
“I think hunters have some things to look forward to if we get spring and fall weather patterns that drive migrations.”
At the same time, Moorman said annual decreases can’t be totally ignored.
“It (mallard decrease) looks big, and it is big,” he said. “The way I phrase this is, you think about yourself in a hunting blind, would you notice one less bird in a flock of 10? From a hunter’s perspective, my observation on ducks is going to be much more dependent on local conditions.
“If you get the weather, and you have a breeding population of 10 million, you’ll be a pretty happy hunter. If you don’t get the weather or don’t have good habitat, you’re probably not going to be as happy.”
The numbers are also a bit clouded by the fact that Ducks Unlimited no longer does a July survey. Moorman said nesting areas had plenty of water when ducks arrived this spring. However, most nesting areas received little rainfall during the summer.
Those conditions could lead to less successful nesting, and make ducklings more susceptible to predators.
Despite those concerns, mallard, gadwall, wigeon, green-winged, blue-winged teal, shoveler, redhead and canvasback populations are strong.
“Pintails are a little problematic,” Moorman said. “Until this year they had dropped for five years in a row. (Pintail showed a 10 percent increase over last year.) That’s a bird we’re still watching. The underlying issues on the prairie where these birds row up are still there. Habitat is down.
“The general thought is that pintails have hit a new lower breeding population total. There used to be 5-6 million, now they hover around 2-3 million. That might be the new reality for pintails.”
More intense agricultural pressure in the wheat-growing area of Canada is believed to be at least partially responsible for the decline in pintail numbers.
“They nest a lot in stubble,” Moorman said. “Two things happened, in Canada there used to be something called summer fallow. It made for great pintail habitat. They switched to more intensive agricultural practices. They really like to nest in wheat stubble.”
Increased planting of an improved winter wheat variety has resulted in fewer fields being plowed up during nesting season. That could lead to a resurgence in pintail numbers.
Scaup are the other problematic species. Moorman scientists still haven’t put their finger on the cause of their decline. Scaup numbers are 13 percent below the long-term average.
Ring-necked ducks are another species of concern.
“I don’t think it is too the point hunters will notice, but those in the management community have an eye on it,” Moorman said. “We’re not looking at a harvest adjustment. We’re trying to figure out if it’s a dip or one of those longer, insidious declines.”