| Merced National Wildlife Refuge | |
|---|---|
IUCN category IV (habitat/species management area) | |
 A flock ofsandhill cranes landing | |
  Map of the United States | |
| Location | Merced County, California,United States |
| Nearest city | Merced, California |
| Coordinates | 37°10′45″N120°38′12″W / 37.17911°N 120.63658°W /37.17911; -120.63658[1] |
| Area | 10,262 acres (41.53 km2) |
| Established | 1951 |
| Governing body | U.S. Fish and Wildlife Service |
| Website | Merced National Wildlife Refuge |
TheMerced National Wildlife Refuge encompasses 10,262 acres (41.53 km2) ofwetlands, nativegrasslands,vernal pools, andriparian areas in California. It was established in 1951 under theLea Act to attract winteringwaterfowl from adjacent farmland where their foraging was causing crop damage. In the last few decades, changes in agricultural practices and refuge management have reduced these wildlife/crop issues.
The refuge plays host to the largest wintering populations oflesser sandhill cranes andRoss's geese within thePacific Flyway. Each autumn over 20,000 cranes and 60,000 arctic nesting geese terminate their annual migrations fromAlaska andCanada to make the refuge home for six months. Here they mingle with thousands of other visiting waterfowl, waterbirds and shorebirds making the refuge a true winter phenomenon.
The refuge also provides important breeding habitat forSwainson's hawks,tri-colored blackbirds,marsh wrens,mallards,gadwall,cinnamon teal, andburrowing owls. Tri-colored blackbirds, a colonial-nestingsongbird, breed in colonies of over 25,000 pairs.Coyotes,ground squirrels,desert cottontail rabbits,beaver, andlong-tailed weasels can also be seen year-round.
Vernal pools are another type of wetland found on the Merced National Wildlife Refuge. These special pools form when natural shallow depressions underlaid with clay soils fill with winter rainwater. The pools come to life as they fill with water:fairy andtadpole shrimp emerge fromcysts embedded in the soils the previous year. Theendangeredtiger salamander, along with other amphibians, lays eggs and rear tadpoles. The vast number of aquatic invertebrates found in these pools provides a food source for wintering and migrating birds as they prepare for the long flight north to their breeding grounds.
As spring arrives and the water in the vernal pools evaporates, wildflowers – such asgoldfields,purple owl's clover, andbutter-and-eggs – germinate in colorful patterns of thick rings or halos around the pool basins. Once the vernal pools have dried out,Downingia andColusa grass, a rare California species, appear in the parched basins. This annual coloring ledJohn Muir to describe the valley floor as the "floweriest part of the world" he had seen.
In addition to managing natural habitats, the Merced National Wildlife Refuge contains approximately 300 acres (1.2 km2) of cultivatedcorn and winterwheat crops and over 500 acres (2.0 km2) of irrigated pasture for wildlife. Not only do these managed agricultural areas provide important sources of nutrition (carbohydrates) to the tens of thousands of arctic-nesting geese and sandhill cranes that make Merced County their winter home, they also help ensure that the birds will have adequate nutrient stores to make the long migration to their northern breeding grounds. Local farmers, under agreements with the refuge, oversee the ground preparation, seeding, and irrigation of these croplands. The refuge incorporates a livestock grazing program that works in partnership with local ranchers and farmers.Grazingcattle andsheep is a management tool used by the refuge to help control invasiveweeds, provide and maintain short stature grasslands for goose grazing, and encourage native grasslands to thrive.
This article incorporatespublic domain material from websites or documents of theUnited States Fish and Wildlife Service.
Media related toMerced National Wildlife Refuge at Wikimedia Commons| International | |
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