The San Luis National Wildlife Refuge Complex is located in the northern
San Joaquin Valley
The San Joaquin Valley ( ; es, Valle de San Joaquín) is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven c ...
, within
Merced County
Merced County ( ), is a county located in the northern San Joaquin Valley section of the Central Valley, in the U.S. state of California.
As of the 2020 census, the population was 281,202. The county seat is Merced. The county is named after ...
and
Stanislaus County
, image_skyline =
, image_caption = Images, from top down, left to right: Modesto Arch, Knights Ferry's General Store, a view of the Tuolumne River from Waterford
, image_flag =
, i ...
of
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
. The complex, with four federal
National Wildlife Refuge
National Wildlife Refuge System is a designation for certain protected areas of the United States managed by the United States Fish and Wildlife Service. The National Wildlife Refuge System is the system of public lands and waters set aside to c ...
s, is managed by the
U.S Fish & Wildlife Service.
Introduction
The complex is composed of the
San Luis National Wildlife Refuge,
Merced National Wildlife Refuge,
San Joaquin River National Wildlife Refuge
The San Joaquin River National Wildlife Refuge is a protected area of along the San Joaquin River in the northern San Joaquin Valley, California. It is within San Joaquin County and Stanislaus County.
It protects more than of riparian woodlan ...
, and the
Grasslands Wildlife Management Area
Grasslands Wildlife Management Area lies within the San Joaquin River basin in California and supports the largest remaining block of wetlands in the Central Valley, containing of private wetlands and associated, and surrounding of state and f ...
. The complex consists of nearly of
wetland
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...
s, grasslands, and
riparian habitats, as well as over of conservation easements on private lands for the protection and benefit of wildlife. The complex is headquartered in
Los Banos, California
Los Banos ( ), alternatively Los Baños ( ), is a city in Merced County, California, United States. It is located in the San Joaquin Valley in central California, near the junction of State Route 152 and Interstate 5. Its population was 45,532 ...
and uses the
Sierra National Forest
Sierra National Forest is a U.S. national forest located on the western slope of central Sierra Nevada in Central California and bounded on the northwest by Yosemite National Park and the south by Kings Canyon National Park. The forest is kno ...
Emergency Communication Center located in
Fresno, California
Fresno () is a major city in the San Joaquin Valley of California, United States. It is the county seat of Fresno County and the largest city in the greater Central Valley region. It covers about and had a population of 542,107 in 2020, makin ...
for emergency dispatch.
The complex is located within the
Pacific Flyway
The Pacific Flyway is a major north-south flyway for migratory birds in the Americas, extending from Alaska to Patagonia. Every year, migratory birds travel some or all of this distance both in spring and in fall, following food sources, heading ...
, a major route for migrating birds, including waterfowl. The extensive wetlands of the complex and surrounding lands provide habitat for up to a million waterfowl that arrive here each winter. Of the 30 species of waterfowl using the complex, the most common include
Ross's geese,
Aleutian cackling geese
The Aleutian cackling goose (''Branta hutchinsii leucopareia''), is a small subspecies of the cackling goose averaging in weight. It was one of 122 species of animals, birds, and fish first documented for science by the Lewis and Clark Expediti ...
,
snow geese
The snow goose (''Anser caerulescens'') is a species of goose native to North America. Both white and dark morphs exist, the latter often known as blue goose. Its name derives from the typically white plumage. The species was previously placed ...
,
green-winged teal
The green-winged teal (''Anas carolinensis'') is a common and widespread duck that breeds in the northern areas of North America except on the Aleutian Islands. It was considered Conspecificity, conspecific with the Eurasian teal (''A. crecca'') ...
,
mallard
The mallard () or wild duck (''Anas platyrhynchos'') is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa, and has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Arge ...
s,
northern pintail
The pintail or northern pintail (''Anas acuta'') is a duck species with wide geographic distribution that breeds in the northern areas of Europe and across the Palearctic and North America. It is migratory and winters south of its breeding ra ...
s,
gadwall
The gadwall (''Mareca strepera'') is a common and widespread dabbling duck in the family Anatidae.
Taxonomy
The gadwall was first described by Carl Linnaeus in his landmark 1758 10th edition of ''Systema Naturae''. DNA studies have shown that ...
s,
American wigeon
The American wigeon (''Mareca americana''), also known as the baldpate, is a species of dabbling duck found in North America. Formerly assigned to ''Anas'', this species is classified with the other wigeons in the dabbling duck genus ''Mareca''. ...
s,
northern shoveler
The northern shoveler (; ''Spatula clypeata''), known simply in Britain as the shoveler, is a common and widespread duck. It breeds in northern areas of Europe and across the Palearctic and across most of North America, wintering in southern Euro ...
s, and
greater white-fronted geese
The greater white-fronted goose (''Anser albifrons'') is a species of goose related to the smaller lesser white-fronted goose (''A. erythropus''). It is named for the patch of white feathers bordering the base of its bill, in fact ''albifrons ...
.
The complex is an integral part of a mosaic of federal, state, and private lands in Merced and Stanislaus Counties that together constitute the largest contiguous freshwater wetlands remaining in California. This area has been recognized as a Ramsar Wetland of International Importance, an Audubon Important Bird Area, and as a Western Hemisphere Shorebird Reserve Network site.
Wildlife refuge units
San Luis National Wildlife Refuge
The
San Luis National Wildlife Refuge encompasses over of wetlands, riparian forests, native grasslands and vernal pools. A thriving population of
tule elk
The tule elk (''Cervus canadensis nannodes'') is a subspecies of elk found only in California, ranging from the grasslands and marshlands of the Central Valley to the grassy hills on the coast. The subspecies name derives from the tule (), a s ...
is showcased by one of three auto tour routes. The refuge is host to significant assemblages of birds, mammals, reptiles, amphibians, insects and plants; some of which, such as the
California tiger salamander
The California tiger salamander (''Ambystoma californiense'') is a vulnerable amphibian native to California. It is a mole salamander. Previously considered to be a subspecies of the tiger salamander (''A. tigrinum)'', the California tiger salam ...
and
San Joaquin kit fox
The endangered San Joaquin kit fox (''Vulpes macrotis mutica'') was formerly very common in the San Joaquin Valley and through much of Central California. Its 1990 population was estimated to be 7,000. This subspecies is still endangered, after n ...
, are
endangered species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...
.
In 1966, the first parcel of the refuge was purchased with
Federal Duck Stamp funds to provide a sanctuary for migratory waterfowl. Over the years the refuge has steadily grown in size and today it comprises six contiguous units: San Luis, East Bear Creek, West Bear Creek, Freitas, Blue Goose, and Kesterson. The
San Joaquin River
The San Joaquin River (; es, Río San Joaquín) is the longest river of Central California. The long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suis ...
bisects the eastern portion of the refuge.
The refuge is a major wintering ground and migratory stopover point for large concentrations of waterfowl, shorebirds and other waterbirds. Large flocks of northern shovelers, mallards, gadwalls, wigeons, green-winged teal,
cinnamon teal
The cinnamon teal (''Spatula cyanoptera'') is a species of duck found in western North and South America. It is a small dabbling duck, with bright reddish plumage on the male and duller brown plumage on the female. It lives in marshes and ponds, ...
, northern pintails,
ring-billed ducks,
canvasback
The canvasback (''Aythya valisineria'') is a species of diving duck, the largest found in North America.
Taxonomy
Scottish-American naturalist Alexander Wilson described the canvasback in 1814. The genus name is derived from Greek ''aithuia'', ...
s,
ruddy duck
The ruddy duck (''Oxyura jamaicensis'') is a duck from North America and one of the stiff-tailed ducks. The genus name is derived from Ancient Greek ''oxus'', "sharp", and ''oura'', "tail", and ''jamaicensis'' is "from Jamaica".
Taxonomy
The ru ...
s, snow geese, Ross's geese, and greater white-fronted geese swarm over the mosaic of seasonal, and permanent wetlands that comprise a quarter of the refuge. Waterfowl generally remain until mid-April before beginning their journey north to breeding areas. Some mallards, gadwalls, and cinnamon teal stay through the spring and summer and breed on the refuge.
Shorebirds including
sandpipers
Sandpipers are a large family, Scolopacidae, of waders. They include many species called sandpipers, as well as those called by names such as curlew and snipe. The majority of these species eat small invertebrates picked out of the mud or soil. ...
and
plovers
Plovers ( , ) are a widely distributed group of wading birds belonging to the subfamily Charadriinae.
Description
There are about 66 species in the subfamily, most of them called "plover" or "dotterel". The closely related lapwing subfa ...
can be found in the tens of thousands from autumn through spring. Large flocks of
dunlin
The dunlin (''Calidris alpina'') is a small wader, formerly sometimes separated with the other "stints" in the genus ''Erolia''. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from ''dun'', "dull brown ...
,
long-billed dowitcher
The long-billed dowitcher (''Limnodromus scolopaceus'') is a medium-sized shorebird with a relatively long bill belonging to the sandpiper family, Scolopacidae. In breeding plumage, adults are characterized by a beautiful rufous head and underpar ...
s,
least sandpiper
The least sandpiper (''Calidris minutilla'') is the smallest shorebird. The genus name is from Ancient Greek ''kalidris'' or ''skalidris'', a term used by Aristotle for some grey-colored waterside birds. The specific ''minutilla'' is Medieval Lat ...
s and
western sandpiper
The western sandpiper (''Calidris mauri'') is a small shorebird. The genus name is from Ancient Greek ''kalidris'' or ''skalidris'', a term used by Aristotle for some grey-coloured waterside birds. The specific ''mauri'' commemorates Italian bota ...
s can be found feeding in shallow seasonal wetlands, whereas flocks of
long-billed curlew
The long-billed curlew (''Numenius americanus'') is a large North American shorebird of the family Scolopacidae. This species was also called "sicklebird" and the "candlestick bird". The species breeds in central and western North America, migrat ...
s are found using both wetlands and grasslands. Over 25 species of shorebirds have been documented at the San Luis NWR.
The San Luis NWR has played a key role in the recovery of the
Tule Elk
The tule elk (''Cervus canadensis nannodes'') is a subspecies of elk found only in California, ranging from the grasslands and marshlands of the Central Valley to the grassy hills on the coast. The subspecies name derives from the tule (), a s ...
, a non-migratory elk subspecies found only in California. Prior to the mid-19th century, an estimated 500,000 Tule Elk lived in California. Due to over-hunting and loss of natural habitat, they were nearly driven to extinction by the turn of the 20th century – by some accounts, the population was down to 10-20 individuals. In 1974 a herd of 18 animals was established in a large enclosure at the San Luis NWR and has since thrived. Elk from this herd are periodically relocated to establish new or join other Tule Elk herds throughout California. A true wildlife recovery success story, the statewide Tule Elk population has recovered to over 4,000 animals.
Less well known are the extensive upland habitats found on the refuge. Many of these habitats are characterized by saline or alkaline conditions which are accentuated by the low rainfall and arid conditions that characterize the San Joaquin Valley. These habitats support a rich botanical community of native
bunchgrasses
Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennia ...
, native and exotic annual grasses, forbs, and native shrubs. Trees, such as the
valley oak,
cottonwood, and
willow
Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...
are found along riparian corridors. In these areas, visitors might encounter
coyotes
The coyote (''Canis latrans'') is a species of canis, canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecologica ...
,
desert cottontail
The desert cottontail (''Sylvilagus audubonii''), also known as Audubon's cottontail, is a New World cottontail rabbit, and a member of the family Leporidae. Unlike the European rabbit (''Oryctolagus cuniculus''), they do not form social burrow s ...
s,
ground squirrels
Ground squirrels are members of the squirrel family of rodents ( Sciuridae), which generally live on or in the ground, rather than trees. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known ...
,
western meadowlark
The western meadowlark (''Sturnella neglecta'') is a medium-sized icterid bird, about in length. It nests on the ground in open grasslands across western and central North America. It feeds mostly on bugs, but will also feed on seeds and berri ...
s,
yellow-billed magpie
The yellow-billed magpie ''(Pica nuttalli)'', also known as the California magpie, is a large bird in the crow family that is restricted to the U.S. state of California. It inhabits the Central Valley and the adjacent chaparral foothills and m ...
s,
loggerhead shrike
The loggerhead shrike (''Lanius ludovicianus'') is a passerine bird in the family Laniidae. It is the only member of the shrike family endemic to North America; the related northern shrike (''L. borealis'') occurs north of its range, however it ...
s, as well as
northern harriers and
white-tailed kite
The white-tailed kite (''Elanus leucurus'') is a small raptor found in western North America and parts of South America. It replaces the related Old World black-winged kite in its native range.
Taxonomy
The white-tailed kite was described in 18 ...
s coursing over the vegetation and other raptors.
Great blue herons
The great blue heron (''Ardea herodias'') is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North America and Central America, as well as the Caribbean and the Galápagos Isl ...
,
great egret
The great egret (''Ardea alba''), also known as the common egret, large egret, or (in the Old World) great white egret or great white heron is a large, widely distributed egret. The four subspecies are found in Asia, Africa, the Americas, and ...
s, and
white-faced ibis
The white-faced ibis (''Plegadis chihi'') is a wading bird in the ibis family, Threskiornithidae.
This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western United States south ...
es are frequently sighted throughout the refuge.
The refuge has three auto tours routes with associated nature trails and observation decks for the public to view and photograph wildlife and nature. The refuge also allows fishing at designated sites and has a large waterfowl hunting program.
Merced National Wildlife Refuge
The
Merced National Wildlife Refuge is within
Merced County
Merced County ( ), is a county located in the northern San Joaquin Valley section of the Central Valley, in the U.S. state of California.
As of the 2020 census, the population was 281,202. The county seat is Merced. The county is named after ...
. It is divided into four units: Merced Unit, Arena Plains Unit, Snobird Unit, and Lonetree Unit.
It encompasses of wetlands, native grasslands,
vernal pool
Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...
s, and
riparian zone
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...
areas. It was established in 1951 under the Lea Act to attract wintering waterfowl 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 of
lesser sandhill cranes and Ross's geese within the Pacific Flyway. Each autumn over 20,000 cranes and 60,000 arctic-nesting geese terminate their annual migrations from
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
and
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
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 for
Swainson's hawk
Swainson's hawk (''Buteo swainsoni'') is a large bird species in the Accipitriformes order. This species was named after William Swainson, a British naturalist. It is colloquially known as the grasshopper hawk or locust hawk, as it is very fond ...
s,
tricolored blackbird
The tricolored blackbird (''Agelaius tricolor'') is a passerine bird of the family Icteridae. Its range is limited to the coastal areas of the Pacific coast of North America, from Northern California in the U.S. (with occasional strays into Oreg ...
s,
marsh wren
The marsh wren (''Cistothorus palustris'') is a small North American songbird of the wren family. It is sometimes called the long-billed marsh wren to distinguish it from the sedge wren, also known as the short-billed marsh wren.
Taxonomy
The ma ...
s, mallards, gadwalls, cinnamon teal, and
burrowing owl
The burrowing owl (''Athene cunicularia''), also called the shoco, is a small, long-legged owl found throughout open landscapes of North and South America. Burrowing owls can be found in grasslands, rangelands, agricultural areas, deserts, or an ...
s. Tricolored blackbirds, a
colonial-nesting songbird, breed in colonies of over 25,000 pairs. Coyotes, ground squirrels, desert cottontails,
beavers
Beavers are large, semiaquatic rodents in the genus ''Castor'' native to the temperate Northern Hemisphere. There are two extant species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers a ...
, and
long-tailed weasel
The long-tailed weasel (''Neogale frenata''), also known as the bridled weasel, masked ermine, or big stoat, is a species of Mustelidae, mustelid distributed from southern Canada throughout all the United States and Mexico, southward through all ...
s can also be seen year-round.
Vernal pools
Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...
are another type of wetland found on the Merced NWR. 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
A fairy (also fay, fae, fey, fair folk, or faerie) is a type of mythical being or legendary creature found in the folklore of multiple European cultures (including Celtic, Slavic, Germanic, English, and French folklore), a form of spirit, ...
and
tadpole shrimp
The order Notostraca, containing the single family Triopsidae, is a group of crustaceans known as tadpole shrimp or shield shrimp. The two genera, '' Triops'' and ''Lepidurus'', are considered living fossils, with similar forms having existed sinc ...
emerge from cysts embedded in the soils the previous year. The endangered
tiger salamander
The tiger salamander (''Ambystoma tigrinum'') is a species of mole salamander and one of the largest terrestrial salamanders in North America.
Description
These salamanders usually grow to a length of with a lifespan of around 12–15 years. ...
, along with other amphibians lay 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 as goldfields,
purple owl's clover, and
butter-and-egg – germinate in colorful patterns of thick rings or halos around the pool basins. Once the vernal pools have dried out, ''
Downingia
''Downingia'' is a genus of 13 annual plants native to western North America and Chile. Commonly known as calico flowers, they are notable for forming mass displays of small but colorful blooms around vernal pool
Vernal pools, also called ver ...
'' and
Colusa grass, a rare California species, appear in the parched basins. This annual coloring led
John Muir
John Muir ( ; April 21, 1838December 24, 1914), also known as "John of the Mountains" and "Father of the National Parks", was an influential Scottish-American naturalist, author, environmental philosopher, botanist, zoologist, glaciologist, a ...
to describe the valley floor as the "floweriest part of the world" he had seen.
In addition to managing natural habitats, the Merced NWR contains approximately of cultivated corn and winter wheat crops and over 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. Grazing cattle and sheep is a management tool used by the refuge to help control invasive weeds, provide and maintain short stature grasslands for goose grazing, and encourage native grasslands to thrive
San Joaquin River National Wildlife Refuge
The
San Joaquin River National Wildlife Refuge
The San Joaquin River National Wildlife Refuge is a protected area of along the San Joaquin River in the northern San Joaquin Valley, California. It is within San Joaquin County and Stanislaus County.
It protects more than of riparian woodlan ...
is located in
Stanislaus County
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, image_caption = Images, from top down, left to right: Modesto Arch, Knights Ferry's General Store, a view of the Tuolumne River from Waterford
, image_flag =
, i ...
and
San Joaquin County
San Joaquin County (; Spanish language, Spanish: ''San Joaquín'', meaning "Joachim, St. Joachim"), officially the County of San Joaquin, is a county (United States), county in the U.S. state of California. As of the 2020 United States Census, 20 ...
. It encompasses over of riparian woodlands, wetlands and grasslands that host a diversity of wildlife native to California's Central Valley. The refuge is situated where three major rivers, the
San Joaquin,
Tuolumne and
Stanislaus River
The Stanislaus River is a tributary of the San Joaquin River in north-central California in the United States. The main stem of the river is long, and measured to its furthest headwaters it is about long. Originating as three forks in the high ...
s, join providing key
wildlife corridor
A wildlife corridor, habitat corridor, or green corridor is an area of habitat connecting wildlife populations separated by human activities or structures (such as roads, development, or logging). This allows an exchange of individuals between ...
habitat. The refuge was established in 1987 under the
Endangered Species Act
The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...
and the
Migratory Bird Treaty Act of 1918
The Migratory Bird Treaty Act of 1918 (MBTA), codified at (although §709 is omitted), is a United States federal law, first enacted in 1918 to implement the convention for the protection of migratory birds between the United States and Canada . ...
.
The refuge has played a major role in the recovery of Aleutian cackling geese by serving as a key wintering area and continues to be of major importance to this species. By 1975, the total population was under 1,000 geese; however, removing nest predators (non-native introduced foxes) from the breeding grounds in Alaska's Aleutian Islands and improving wintering habitat resulted in its delisting as an endangered species and a population well over 100,000 and growing. Restoring wetlands and providing grasslands and croplands at this refuge has provided ideal wintering habitat for the geese.
It is estimated that 95 percent of the San Joaquin Valley's
riparian woodlands were lost during the late 19th and 20th centuries due to changing land and water uses. However, this refuge is in the process of restoring this critical habitat. Within the borders of the San Joaquin NWR is one of California's largest riparian forest
habitat restoration
Restoration ecology is the scientific study supporting the practice of ecological restoration, which is the practice of renewing and restoring degraded, damaged, or destroyed ecosystems and habitats in the environment by active human interrupt ...
projects: 400,000 native trees such as willows, cottonwoods, and oaks have been planted across of river floodplain creating the largest block of contiguous riparian woodland in the San Joaquin Valley. This important riparian woodland habitat is host to many rare animals. Swainson's hawks nest in the canopy of tall cottonwood trees. Herons and cormorants form communal nesting colonies within the tops of the large oaks. Endangered riparian brush rabbits have been re-introduced to this restored habitat from captive-reared populations. These woodlands also support a diversity of breeding songbirds including
grosbeak
Grosbeak is a form taxon containing various species of seed-eating passerine birds with large beaks. Although they all belong to the superfamily Passeroidea, these birds are not part of a natural group but rather a polyphyletic assemblage of dist ...
s,
orioles,
flycatchers,
warblers
Various Passeriformes (perching birds) are commonly referred to as warblers. They are not necessarily closely related to one another, but share some characteristics, such as being fairly small, vocal, and insectivorous.
Sylvioid warblers
Th ...
, as well as least
Bell's vireo
Bell's vireo (''Vireo bellii'') is a songbird that migrates between a breeding range in Western North America and a winter range in Central America. It is dull olive-gray above and whitish below. It has a faint white eye ring and faint wing bars ...
s – a threatened species which last nested in the San Joaquin Valley over 50 years ago.
A wildlife viewing platform along Beckwith Road is a favorite location for viewing the Aleutian cackling geese along with other waterbirds from October through March.
Grasslands Wildlife Management Area
The
Grasslands Wildlife Management Area
Grasslands Wildlife Management Area lies within the San Joaquin River basin in California and supports the largest remaining block of wetlands in the Central Valley, containing of private wetlands and associated, and surrounding of state and f ...
(GWMA) was established by the
U.S. Fish and Wildlife Service
The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with oth ...
in 1979 and is composed of privately owned lands on which perpetual conservation easements have been purchased. These easements preserve wetland and grassland habitats and prevent conversion to croplands or other uses not compatible with migratory bird and other wildlife values. Daily management operations remain under the landowner's control. The majority of easement properties are wetlands managed for waterfowl hunting. From 1979 to-date, over have been placed under conservation easements.
The GWMA is located in western
Merced County, California
Merced County ( ), is a county located in the northern San Joaquin Valley section of the Central Valley, in the U.S. state of California.
As of the 2020 census, the population was 281,202. The county seat is Merced. The county is named after ...
, within the
San Joaquin River
The San Joaquin River (; es, Río San Joaquín) is the longest river of Central California. The long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suis ...
basin and supports the largest remaining block of contiguous wetlands in the Central Valley. It is divided into an eastern and western division separated by the San Joaquin River. In the heart of the western division is the Grassland Resource Conservation District (GRCD), an area of of private wetlands and associated grasslands, and over of federal National Wildlife Refuges and state Wildlife Management Areas.
These private wetlands constitute 30% of the remaining wetlands in California's Central Valley and are extremely important to Pacific Flyway waterfowl populations. Over 60 million duck use-day and 3 million goose use-days occur annually in the GWMA. The wetlands support diverse habitats including seasonally flooded marshlands, semi-permanent marsh, riparian habitat, wet meadows, vernal pools, native uplands, pastures, and native grasslands. This habitat diversity supports raptors, shorebirds, wading birds, and other wildlife species. Several federal and state listed, endangered, and threatened plants and animals are present in the area and benefit by the habitat protection provided by the easement program.
See also
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References
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National Wildlife Refuges in California
Parks in the San Joaquin Valley
San Luis
Wetlands of California
Protected areas of Merced County, California
Protected areas of Stanislaus County, California
Natural history of the Central Valley (California)
Los Banos, California
San Joaquin River
Geography of Merced County, California
Geography of Stanislaus County, California
Animal shelters in the United States
Animals and humans
Grasslands of California