Salt Marsh Harvest Mouse
Encyclopedia
The Salt Marsh Harvest Mouse (Reithrodontomys raviventris), also known as the Red-bellied Harvest Mouse and some times called by Saltmarsh Harvest Mouse, is an endangered
rodent
endemic
to the San Francisco Bay Area
salt marsh
es in California
. There are two distinct subspecies
, both endangered and listed together on federal and state endangered species lists. The northern subspecies (Reithrodontomys raviventris halicoetes) is lighter in color and inhabits the northern marshes of the bay, and the southern subspecies (Reithrodontomys raviventris raviventris) lives in the East and South Bay marshes. They are both quite similar in appearance to their parent species, the Western harvest mouse
. Its endangered designation is due to its limited range, historic decline in population and continuing threat of habitat loss due to development encroachment at the perimeter of San Francisco Bay.
s are grooved.
This species is nocturnal
, with particularly noted activity on moonlit nights. This mouse is particularly resourceful, making use of ground runways of other rodents; moreover, he also exhibits climbing agility. It enjoys subsisting in marsh habitats where glasswort
abounds. Luckily the glasswort plant has been increasing around the San Francisco Bay perimeter since the 1980s. Its many predators feature hawk
, snake
and owl
species, as well as shorebirds and larger mammal
s. Predation by domestic cat
s is an issue due to encroachment of the limited habitat by humans at the perimeter of the San Francisco Bay.
As would be expected of a mouse native to salt marsh
es, this species is a competent swimmer and is tolerant of salt in its diet and water supply. It can drink salt water for extended periods of time if necessary, and sometimes even prefers it to fresh. It eats seeds and plants, especially pickleweed and glasswort
, one of the most common salt marsh plant species.
Similar species are the Plains Harvest Mouse
, which has a distinct but narrower stripe on its spine, and the Fulvous Harvest Mouse
, which has a longer tail. Also similar is the Western harvest mouse
, which has an underbelly fur that is whitish in color and an indistinct white stripe along the fur above its spine
. Finally the House mouse
has incisor
s without grooves, unlike those of the Salt Marsh Harvest Mouse.
s. Individual political jurisdictions have conducted research and established habitat protection strategies to protect the Salt Marsh Harvest Mouse. For example, the city of San Rafael, California
has established a shoreline setback standard to prevent any land development within fifty feet of the shoreline; this measure has been applied to several specific land developments along the San Francisco Bay
shoreline.
. The mouse was mentioned numerous times in congress by Republicans
such as Rep. Mike Pence
and Rep. Dan Lungren
to highlight the wasteful spending of the bill. The main allegation was, that $30m of the 2009 economic stimulus will be spent on habitat restoration to protect the mouse. The rumor was started by Michael Steel
, press secretary for John Boehner. This was disputed in a San Francisco Chronicle
article by Democratic U.S. Rep Jackie Speier
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
to the San Francisco Bay Area
San Francisco Bay Area
The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California. The region encompasses metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas...
salt marsh
California coastal salt marsh
California's coastal salt marsh is a wetland Plant community that occurs sporadically along the Pacific coast from Humboldt Bay to San Diego. This salt marsh type is found in bays, harbors, inlets and other protected areas subject to tidal flooding....
es in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. There are two distinct subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
, both endangered and listed together on federal and state endangered species lists. The northern subspecies (Reithrodontomys raviventris halicoetes) is lighter in color and inhabits the northern marshes of the bay, and the southern subspecies (Reithrodontomys raviventris raviventris) lives in the East and South Bay marshes. They are both quite similar in appearance to their parent species, the Western harvest mouse
Western harvest mouse
The Western Harvest Mouse is a small neotomine mouse native to southwest British Columbia, most of the western United States extending continuously to west Texas, northeast Arkansas, northwest Indiana, southwest Wisconsin, the interior of Mexico to Oaxaca...
. Its endangered designation is due to its limited range, historic decline in population and continuing threat of habitat loss due to development encroachment at the perimeter of San Francisco Bay.
Description and comparison to similar species
The Salt Marsh Harvest Mouse has dark brown fur above and a pinkish cinnamon or tawny belly; moreover, the tail is likewise bicolored. An adult's length is twelve to eighteen centimeters (5 to 7 inches) and a tail length of six to ten centimeters (2 to 4 inches). The height is between 1.5 and 2.1 centimeters (0.6 to 0.8 inches). Weight of a mature mouse is approximately 10 to 20 grams (0.35 to 0.7 ounces). The upper incisorIncisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s are grooved.
This species is nocturnal
Nocturnal animal
Nocturnality is an animal behavior characterized by activity during the night and sleeping during the day. The common adjective is "nocturnal"....
, with particularly noted activity on moonlit nights. This mouse is particularly resourceful, making use of ground runways of other rodents; moreover, he also exhibits climbing agility. It enjoys subsisting in marsh habitats where glasswort
Glasswort
Salicornia is a genus of succulent, halophyte plants that grow in salt marshes, on beaches, and among mangroves. Salicornia species are native to North America, Europe, South Africa, and South Asia...
abounds. Luckily the glasswort plant has been increasing around the San Francisco Bay perimeter since the 1980s. Its many predators feature hawk
Hawk
The term hawk can be used in several ways:* In strict usage in Australia and Africa, to mean any of the species in the subfamily Accipitrinae, which comprises the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter genus includes goshawks,...
, snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
and owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
species, as well as shorebirds and larger mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s. Predation by domestic cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s is an issue due to encroachment of the limited habitat by humans at the perimeter of the San Francisco Bay.
As would be expected of a mouse native to salt marsh
Salt marsh
A salt marsh is an environment in the upper coastal intertidal zone between land and salt water or brackish water, it is dominated by dense stands of halophytic plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh...
es, this species is a competent swimmer and is tolerant of salt in its diet and water supply. It can drink salt water for extended periods of time if necessary, and sometimes even prefers it to fresh. It eats seeds and plants, especially pickleweed and glasswort
Glasswort
Salicornia is a genus of succulent, halophyte plants that grow in salt marshes, on beaches, and among mangroves. Salicornia species are native to North America, Europe, South Africa, and South Asia...
, one of the most common salt marsh plant species.
Similar species are the Plains Harvest Mouse
Plains Harvest Mouse
The Plains Harvest Mouse is a species of rodent in the family Cricetidae.It is found in northern Mexico and the central United States.-References:...
, which has a distinct but narrower stripe on its spine, and the Fulvous Harvest Mouse
Fulvous Harvest Mouse
The Fulvous Harvest Mouse is a species of rodent in the family Cricetidae.It is found in El Salvador, Guatemala, Honduras, Mexico, Nicaragua, and the United States.-References:...
, which has a longer tail. Also similar is the Western harvest mouse
Western harvest mouse
The Western Harvest Mouse is a small neotomine mouse native to southwest British Columbia, most of the western United States extending continuously to west Texas, northeast Arkansas, northwest Indiana, southwest Wisconsin, the interior of Mexico to Oaxaca...
, which has an underbelly fur that is whitish in color and an indistinct white stripe along the fur above its spine
Vertebral column
In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...
. Finally the House mouse
House mouse
The house mouse is a small rodent, a mouse, one of the most numerous species of the genus Mus.As a wild animal the house mouse mainly lives associated with humans, causing damage to crops and stored food....
has incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s without grooves, unlike those of the Salt Marsh Harvest Mouse.
Range
This organism is known to be found in the following specific locales (among others):- Sonoma CreekSonoma CreekSonoma Creek is a stream in northern California. It is one of two principal drainages of southern Sonoma County, California, with headwaters rising in the rugged hills of Sugarloaf Ridge State Park and discharging to San Pablo Bay, the northern arm of San Francisco Bay. The watershed drained by...
discharge area known as the Napa Sonoma MarshNapa Sonoma MarshThe Napa Sonoma Marsh is a wetland at the northern edge of San Pablo Bay, which is a northern arm of the San Francisco Bay in California, USA. This marsh has an area of 48,000 acres , of which 13,000 acres are abandoned salt evaporation ponds... - Alman Marsh, adjacent to Shollenberger ParkShollenberger parkShollenberger Park is a wetland park located in Petaluma, California.. Together with the Alman Marsh, and Ellis Creek opening to the public in July 2009, a total of will be accessible to the public. Named after Richard Shollenberger, a park chief, the park is one of the last wetlands of its...
, Petaluma - Sausalito baylands
- San RafaelSan Rafael, CaliforniaSan Rafael is a city and the county seat of Marin County, California, United States. The city is located in the North Bay region of the San Francisco Bay Area...
baylands - San Francisco BaySan Francisco BaySan Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
sloughs in Alviso
Conservation
The Salt Marsh Harvest Mouse has been forced out of much of its habitat by extensive development of bayside marshland. Pollution, boat activity, commercial salt harvesting; moreover, decrease in native plant material has also reduced the species' numbers. It has been on the endangered lists since the 1970s, and has protected habitat within numerous Bay Area wildlife refugeWildlife refuge
A wildlife refuge, also called a wildlife sanctuary, may be a naturally occurring sanctuary, such as an island, that provides protection for species from hunting, predation or competition, or it may refer to a protected area, a geographic territory within which wildlife is protected...
s. Individual political jurisdictions have conducted research and established habitat protection strategies to protect the Salt Marsh Harvest Mouse. For example, the city of San Rafael, California
San Rafael, California
San Rafael is a city and the county seat of Marin County, California, United States. The city is located in the North Bay region of the San Francisco Bay Area...
has established a shoreline setback standard to prevent any land development within fifty feet of the shoreline; this measure has been applied to several specific land developments along the San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
shoreline.
Reference in 2009 economic stimulus debate
The preservation of the Salt Marsh Harvest Mouse habitat was a subject of discussion in 2009 Economic Stimulus packageAmerican Recovery and Reinvestment Act of 2009
The American Recovery and Reinvestment Act of 2009, abbreviated ARRA and commonly referred to as the Stimulus or The Recovery Act, is an economic stimulus package enacted by the 111th United States Congress in February 2009 and signed into law on February 17, 2009, by President Barack Obama.To...
. The mouse was mentioned numerous times in congress by Republicans
Republican Party (United States)
The Republican Party is one of the two major contemporary political parties in the United States, along with the Democratic Party. Founded by anti-slavery expansion activists in 1854, it is often called the GOP . The party's platform generally reflects American conservatism in the U.S...
such as Rep. Mike Pence
Mike Pence
Michael Richard "Mike" Pence is the U.S. Representative for Indiana's , and previously the , serving since 2001. The 6th district covers much of Eastern Indiana. He is a member of the Republican Party....
and Rep. Dan Lungren
Dan Lungren
Daniel Edward "Dan" Lungren is the U.S. Representative for , serving since 2005. The district covers most of Sacramento County and part of Solano County, as well as all of Alpine, Amador and Calaveras counties...
to highlight the wasteful spending of the bill. The main allegation was, that $30m of the 2009 economic stimulus will be spent on habitat restoration to protect the mouse. The rumor was started by Michael Steel
Michael Steel (North Carolina)
Michael Steel is the spokesman for House Speaker John Boehner. He has a bachelor's degree from the University of North Carolina and a master's degree in journalism from Columbia University. Steel has previously worked as the press secretary for Representatives John Shadegg and Jim McCrery. He...
, press secretary for John Boehner. This was disputed in a San Francisco Chronicle
San Francisco Chronicle
thumb|right|upright|The Chronicle Building following the [[1906 San Francisco earthquake|1906 earthquake]] and fireThe San Francisco Chronicle is a newspaper serving primarily the San Francisco Bay Area of the U.S. state of California, but distributed throughout Northern and Central California,...
article by Democratic U.S. Rep Jackie Speier
Jackie Speier
Karen Lorraine Jacqueline "Jackie" Speier is the U.S. Representative for , serving since 2008. She is a member of the Democratic Party. The district includes the northern two-thirds of San Mateo County and the southwest quarter of San Francisco.She is also a former member of the California State...
Further reading
- National Audubon Society Field Guide to North American Mammals, ed. by John O. Whitaker Jr., Chanticleer Press (1997) ISBN 0-679-44631-1 Database entry includes a brief justification of why this species is vulnerable and the criteria used