The distinct, soothing warble of a sandhill crane floated across marsh water and through tall cattails, wafting down into a waterfowl hunter’s camouflage blind.
Placid water filled the grassy wetlands, disturbed only by a light wind or the liftoff of an egret or mallard.The Merced National Wildlife Refuge looks peaceful and serene. But considerable action buzzes under the surface to get the marshland ready for this season.
October is a prime time for visitors, whether they come by boot or wing. And wildlife managers spend months preparing the 10,262 acres of refuge space for thousands of birds flying in from Alaska and Canada to winter here.
Much of these efforts benefit hunters. On Saturday they descended on the western and southern portions of the refuge for the start of waterfowl hunting season. Eighteen hunt blinds are now open on Wednesdays and Saturdays until Jan. 27.
Not everyone comes bearing firearms. Photographers and birders know this is also the time to hunt for sightings. Red-tailed hawks, great blue herons, black-necked stilts, northern shovelers and many more species can be spotted by anyone traveling the auto-tour route at the center of the refuge. “We’re getting into prime birding season,” said Rich Albers, assistant wildlife refuge manager for the Merced refuge.
More than 18,000 Lesser sandhill cranes have been counted on the refuge as of last week, he said. Wildlife managers are offering free guided Crane Day tours on Oct. 27, beginning at 8 a.m., for anyone hoping to spot flocks of these dramatic 4-foot-tall white and red-capped birds.
Although thanks must always be given to Mother Nature, she isn’t the only one keeping this space in shape to welcome its hunters, birders and wildlife.
Less than 5 percent of the wetlands stay wet all year round. Their water is drained in the spring and flooded in the fall. This is to mimic the natural pattern of nature that would occur if the San Joaquin River’s tributaries still touched this area, said Jack Sparks, outdoor recreation planner for the San Luis National Wildlife Complex, which the Merced refuge is a part of.
This process stimulates the growth of plants that feed the birds, such as swamp timothy and smartweed. Plants need a dry period to germinate and a wet period to grow, Albers said. The invertebrates birds feed on also thrive in these alternating wet and dry conditions.
Merced Irrigation District supplies about 15,000 acre- feet of water to begin flooding this land toward the end of August. (One acre-foot of water, according to U.S. consumption rates, is enough to meet the industrial and municipal needs of four people for a year.)
After the MID irrigation season ends in late October, the marshes depend on groundwater pumps to fill them. But drought caused the season to end early this year, sending wetland managers to the pumps early — which has made the refilling process go slower, Albers said. “Wells don’t pump the same amount. It takes more energy. It’s more touch and go.”
When the 41 wetland pools in the Merced refuge are drained from February to April, the water flows into the east side bypass and eventually spills into San Joaquin River. Some of it also kept and recycled for the small percentage of marshes that stay filled in the summer.
Other maintenance is ongoing to keep these natural spaces in play. Three or four marshes each year get rehabbed every five to seven years. Once these wetlands are drained, wildlife managers disk the land to turn soil over and stimulate plant growth or rid the area of weeds. Some marshes are also flushed out and mowed. “These wetlands are evolving,” Albers said. “They get more mature, vegetation gets higher and thicker. Going in and disking it up allows for more desirable food plants.”
While the refuge maintains a selection of growth that attracts wildlife for habitat or food, plants must be managed to appeal to a range of finicky birds. Cattails are good for cover, but they can grow out of control fast and must be trimmed often.
Some birds like to hide in dense vegetation, while other like more open water — this is all taken under consideration in deciding tactics for the refuge’s upkeep. Pastures of corn are also grown on site to give the birds a boost of carbohydrates before they leave for their long flight home at the end of the season.
The California Department of Fish and Game keeps the hunters who benefit from this process in check. During hunting season Fish and Games works with the U.S. Fish and Wildlife Service, which manages this refuge, to ensure that everyone respects the land, shoots by the rules and stays safe.
Hunters get to the refuge before the sun rises, so light is a key safety issue, said Jason Strohmenger, Fish and Game check station manager at the Merced refuge. Proper lighting and parking must be provided as they check in to show their licenses and hear about regulations and limits on the birds they can take home.
This season the daily bag limit is seven, which may include up to seven mallards, but not more than two females; one pintail; one canvasback, two redheads and three scaup.
It takes about two-and-a-half weeks to organize the check station and parking lot before hunting season, Strohmenger said, but much like marsh maintenance, the planning goes year-round.
Hunters, birders and waterfowl aren’t the only ones who benefit from this land management. “Other species depend on this, although waterfowl is the big eye catcher,” Sparks explained.
About 250 species of birds can be found between Los Banos and Merced, but coyotes, cotton tail rabbits, badgers and other critters also depend on this wetland habitat.
And they also depend on wildlife managers to give Mother Nature the push and pull she needs to keep the hydraulic cycle moving.
Reporter Dhyana Levey can be reached at 209 385-2472 or firstname.lastname@example.org