They may not have the gravitas of bald eagles or the mysterious allure of condors, but North America’s ducks — a classic harbinger every year of the changing seasons — have done something remarkable.
Scientists say the number of mallards, teals, canvasbacks and other ducks this year has reached the highest level ever recorded, with a total estimate of 48.6 million breeding ducks in Canada and the United States.
The number is 7 percent higher than last year, according to a survey released this week from the U.S. Fish and Wildlife Service, and 43 percent higher than the historic average going back to 1955.
The trend is good news for hunters, bird watchers and biologists, experts say, but also for people who live near areas like San Francisco Bay, which is a key stop for migrating ducks every fall along the Pacific Flyway.
“I’m excited. It’s encouraging,” said Walt Rhodes, a flyway biologist with the U.S. Fish and Wildlife Service who flew thousands of miles in small planes surveying the birds this spring.
“It let’s you know that maybe we’re doing something right,” he said. “Overall it seems like things are headed in the right direction. A wetland without waterfowl is just not right.”
More than a dozen duck species fly south every year for the winter, some traveling thousands of miles from Alaska, the Yukon Territory, the Dakotas and other Northern areas to warmer wintering grounds across the United States and into Mexico.
There the birds fatten up and head north again every April to breed, lay eggs and raise a new generation for the annual migration. But when they return north, the birds need wetlands and wild grassy areas to stay free from predators and raise their young.
Researchers say favorable weather conditions in 2010 and 2011 — mainly rains in the spring and significant snow melt — have created lots of new wetlands and ponds in the Canadian prairies where ducks breed. Places like Saskatchewan are so important to waterfowl populations, they are known as the “duck factory.”
“Last year, we made a pile of ducks. This year, we’re counting them,” said Frank Rohwer, the scientific director for Delta Waterfowl, a research and advocacy group based in Bismarck, N.D.
More ducks means more food for predators, such as peregrine falcons, golden eagles, foxes and bobcats.
Drought conditions in the 1980s and a steady loss of wetlands to farming and development sent duck populations crashing by the mid-1980s to about 25 million. Alarmed, federal regulators reduced the hunting season to 30 days and the bag limit to three ducks per hunter in many areas. Today, by comparison, the hunting season and bag limits have doubled.
Along with a run of good weather years, several key events sent populations rising steadily to today’s record levels.
In 1985, President Reagan signed a farm bill that created a new program that paid farmers if they allowed some parts of their lands to go fallow and planted native grasses, trees and other vegetation. Known as the Conservation Reserve Program, the policy created millions of acres of new habitat for ducks, pheasants and other wildlife, and a similar program was put in place by Canada.
Also, a ban on lead shot 20 years ago in national wildlife refuges reduced the number of ducks that died from lead poisoning, Rhodes said. And rice farmers in areas from the Sacramento Valley to Texas have been flooding their fields in the winter, creating habitat for ducks, rather than burning the leftover rice plants.
Despite the positive trends, however, there are significant concerns still looming.
This year was drier than normal across much of Canada and the Northern Plains. This week’s survey found a 32 percent reduction in ponds there compared to last year, although the total number is still up slightly from the historic average. That could mean duck populations in future years may fall if dry conditions continue.
Meanwhile, in an effort to save money, Congress is cutting back on the Conservation Reserve Program. Last week the Senate passed a new farm bill that reduces the acreage that can be preserved under the program from 32 million acres nationwide to 25 million acres by 2017. The House is expected to follow suit.
Come September or October, this year’s migration of mallards, wigeons, teals and other ducks will begin arriving in San Francisco Bay, the vast grasslands of Merced County and other parts of Northern California.
“Ducks are an indicator of the overall health of the environment,” said Mark Biddlecomb, operations director for Ducks Unlimited, a nonprofit conservation and hunting organization, in Sacramento.
“If we can sustain numbers of birds like we’re seeing now in Canada and the U.S., then we have a healthy environment. And if the numbers are going down, then the environment is not what it should be.”
Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/PaulRogerssjmn.
