The Bill Williams River National Wildlife Refuge protects the lower course of the

Bill Williams River The Bill Williams River is a river in west-central Arizona where it, along with one of its tributaries, the Santa Maria River, form the boundary between Mohave County to the north and La Paz County to the south.''Arizona Atlas & Gazetteer,'' D ...

, to its mouth at

Lake Havasu Lake Havasu () is a large reservoir formed by Parker Dam on the Colorado River, on the border between San Bernardino County, California and Mohave County, Arizona, Arizona. Lake Havasu City sits on the Arizona (eastern) side of the lake with its ...

reservoir, in western

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

. It is located within eastern La Paz and Mohave Counties, in the Lower Colorado River Valley region. The federal

wildlife refuge A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or ...

is managed by the

United States 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 othe ...

. Recreation activities include nature walks,

bird watching Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device like binoculars or a telescope, by ...

, hiking, and kayaking on the

.Recreation.gov: Bill Williams River Wildlife Refuge info
/ref>

Natural history

The

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s of the refuge are a unique blend of

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily ...

and

Sonoran Desert The Sonoran Desert ( es, Desierto de Sonora) is a desert in North America and ecoregion that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the southwestern United States (in Ariz ...

uplands, desert

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 a ...

s, and

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

wetlands habitats, provides for a diverse array of

flora Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' ...

and fauna.

Flora

The

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

within the Bill Williams River National Wildlife Refuge is situated in an

ecotone An ecotone is a transition area between two biological communities, where two communities meet and integrate. It may be narrow or wide, and it may be local (the zone between a field and forest) or regional (the transition between forest and gras ...

(transition zone) between

and

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

s, increasing diversity of plant species present within it, There are few places in the Arizona deserts where one can view

saguaro The saguaro (, ) (''Carnegiea gigantea'') is a tree-like cactus species in the monotypic genus ''Carnegiea'' that can grow to be over tall. It is native to the Sonoran Desert in Arizona, the Mexican state of Sonora, and the Whipple Mountai ...

cacti forests, wetland broadleaf cattail (''Typha latifolia'') stands, and cottonwood woodlands in a single viewshed. The refuge protects the largest remaining stand of the cottonwood-willow forests

plant community A plant community is a collection or association of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighboring patches of different vegetation types. The components of each plant ...

along the lower Colorado River, with Fremont's cottonwood (''Populus fremontii'') and Goodding's willow (''Salix gooddingii'') the primary tree species.

Fauna

The rare desert context

riparian habitat 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 ...

of Bill Williams River NWR supports diverse resident fauna, and draws a variety of

neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

migratory bird Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting b ...

s, from Central and South America en route to their breeding grounds in the north.US-FWS: Bill Williams River Overview
. accessed 6.4.2014
/ref> The refuge is host to some endangered bird species, including the southwestern willow flycatcher (''Empidonax traillii extimus''), which nests on the refuge; and the Yuma rail (''Rallus obsoletus yumanensis'') which lives in the marsh's broadleaf cattail colonies, and is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the Lower Colorado River Valley. This refuge's wildlife includes: * Birds:

southwestern willow flycatcher The willow flycatcher (''Empidonax traillii'') is a small insect-eating, neotropical migrant bird of the tyrant flycatcher family. There are four subspecies of the willow flycatcher currently recognized, all of which breed in North America (inc ...

vermilion flycatcher The vermilion flycatcher (''Pyrocephalus obscurus'') is a small passerine bird in the tyrant flycatcher family found throughout South America and southern North America. It is a striking exception among the generally drab Tyrannidae due to its v ...

yellow-billed cuckoo The yellow-billed cuckoo (''Coccyzus americanus'') is a cuckoo. Common folk-names for this bird in the southern United States are rain crow and storm crow. These likely refer to the bird's habit of calling on hot days, often presaging rain or th ...

western tanager The western tanager (''Piranga ludoviciana''), is a medium-sized American songbird. Formerly placed in the tanager family (Thraupidae), other members of its genus and it are classified in the cardinal family (Cardinalidae). The species's pluma ...

, lazuli bunting, Yuma rail * Mammals:

North American beaver The North American beaver (''Castor canadensis'') is one of two extant beaver species, along with the Eurasian beaver (''Castor fiber''). It is native to North America and introduced in South America ( Patagonia) and Europe (primarily Finland ...

, bobcat, cougar,

gray fox The gray fox (''Urocyon cinereoargenteus''), or grey fox, is an omnivorous mammal of the family Canidae, widespread throughout North America and Central America. This species and its only congener, the diminutive island fox (''Urocyon littor ...

collared peccary The collared peccary (''Dicotyles tajacu'') is a species of artiodactyl (even-toed) mammal in the family Tayassuidae found in North, Central, and South America. It is the only member of the genus ''Dicotyles''. They are commonly referred to as ...

mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whi ...

desert bighorn sheep The desert bighorn sheep (''Ovis canadensis nelsoni'') is a subspecies of bighorn sheep (''Ovis canadensis'') that is native to the deserts of the United States' intermountain west and southwestern regions, as well as northwestern Mexico. The ...

ring-tailed cat The ringtail (''Bassariscus astutus'') is a mammal of the raccoon family native to arid regions of North America. It is widely distributed and well adapted to disturbed areas. It has been legally trapped for its fur. It is listed as Least Co ...

. * Amphibians: Colorado River toad (''Incilius alvarius'') * Fish:

razorback sucker The razorback sucker (''Xyrauchen texanus'') is a suckerfish found in rivers and lakes in the southwestern United States. It can grow to in length and is recognisable by the keel between its head and dorsal fin. It used to inhabit much of the C ...

and

bonytail chub The bonytail chub or bonytail (''Gila elegans'') is a cyprinid freshwater fish native to the Colorado River basin of Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming in the southwestern United States; it has been extirpated fro ...

Friends of the Refuge

The Friends of the Bill Williams River and Havasu National Wildlife Refuges is a

non-profit A nonprofit organization (NPO) or non-profit organisation, also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a collective, public or social benefit, in co ...

membership organization that supports the Bill Williams River National Wildlife Refuge and the Havasu National Wildlife Refuge up on the

Colorado River The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. s ...

. They advocate for and strive to obtain grants to support refuge projects, conduct fund-raising activities to support environmental education programs, assist refuge staff with several of the refuge's annual events, and help the Fish and Wildlife Service operate and maintain the refuge facilities and programs by providing volunteer labor.Friends of the Bill Williams River and Havasu National Wildlife Refuges
/ref>

References

External links