Delmarva fox squirrel
Encyclopedia
The Delmarva fox squirrel, Sciurus niger cinereus, is an endangered subspecies
of the fox squirrel
.
, southeastern Pennsylvania and southern New Jersey, but its natural occurrence is now limited to parts of the Eastern Shore of Maryland and Virginia. In these areas the Delmarva fox squirrel's habitat has been degraded and its survivability rates have decreased. It has, however, been successfully reintroduced in other parts of its historical range.
Like all fox squirrels, the Delmarva fox squirrel has a full, fluffy tail. The Delmarva fox squirrel is frosty silver to slate gray with a white belly and can grow to be 75 centimetres (29.5 in) long, including up to 38 centimetres (15 in) of tail. They weigh around three pounds.
The Delmarva fox squirrel like many squirrel species, use trees to elude predators. Their preferred habitat is mature forest of both hardwood
and pine trees with an open understory
. An open understory within the forest is needed for the squirrels to successfully feed on nuts and seeds of the many trees such as oaks, hickories, sweet gum, walnut, and loblolly pine during the fall season when these trees are dispersing their seeds. In the summer and early fall they often feed on mature green pine cones. Other less important food sources include bud
s, fruit
, insect
s, and grain
.
These fox squirrels prefer to make their dens in the hollows of trees. However, they will also make a nest of leaves and twigs in the crotch of a tree, in a tangle of vines on a tree trunk, or near the end of a large branch.
Mating
occurs in late winter and early spring. Gestation
is about 44 days, with most young born between February and April. Litters average 1-6 young, which the female raises by herself.
Over the past several years the populations of Delmarva fox squirrels have been declining rapidly and in 1967 the U.S. Fish and Wildlife Service listed them as an endangered species.
by the U.S. Fish and Wildlife Service in 1967. A recovery plan was developed in 1979 and revised in 1983 and 1993. A principal strategy for species recovery is protection of its habitat
.
The Delmarva fox squirrel was listed as an endangered species in 1967 because only 10% of their historical population was remaining. The cause of their significant decline in individuals was due to overhunting and habitat loss or destruction. Habitat destruction has been influenced by timber harvesting and farm land production. Housing developments, roads and increased commercial property are some other major factors for the continued loss of habitat. Along with human induced causes, predation plays a large role in the decline of numbers. Red and gray foxes, weasels, minks, eagles and other animals are the cause of high predation rates as the Delmarva Fox Squirrel’s habitat is within their range.
Many efforts have been made to restore habitat and increase the number of Delmarva fox squirrels within their historical range.
In 1979, the first recovery plan was developed to protect the habitat and increase the population of the Delmarva fox squirrel (. In completing this plan, the biologists projected that the habitat would become more suitable to the lifestyle of the squirrels as well as other animals that share the same habitat. The plan consisted of 11 sites in Maryland that attempted to reintroduce between 8 and 42 individuals within a 1-3 year process. At each site the same number of males and females were released to assess the reproduction rates and survivability of each sex. Many tests were done after reintroduction by live trapping and recruitment within 9 of the overall 11 sites.
In a more recent conservation effort many private and publicly owed lands were used to serve as habitat restoration areas. Private lands within the Delmarva fox squirrel range constitute for ~87% of the entire historical range of the DFS, while only 13% is of public land. A relationship between both public and private land owners allowed habitat restoration to occur in the 1990s. Different techniques were used by the Chesapeake Bay/Susquehanna River Ecoteam on public lands to monitor and reintroduce the Delmarva fox squirrel. Many private land owners also contributed to the restoration process by allowing biologists to assess their land.
Within the recovery plan made in the late 1970s, the idea of translocations was a prominent tool used to increase the population of the Delmarva fox squirrel. The most recent effort allowed for trapping and relocation of the Delmarva fox squirrel to different habitats that would allowed them to survive. The major goal was to reduce the probability of extinction, restore ecological diversity, and broaden the involvement of many areas in conservation effort. 83 squirrels were used in this effort and they were all radio-collared for post release tracking. The radio collars let biologists study the range and movements of the squirrels and tracked the distance traveled within a certain time period.
The Delmarva fox squirrel conservation effort has been an increasing success. The population within the historical range has increased and the many efforts have allowed for the habitats to become bettered suited for the Delmarva fox squirrel. Many issues have threatened the DFS with extinction but continued work to restore habitat must be done in order for this species to have a sustainable population and for the Delmarva Fox Squirrels to be released from the Endangered Species List.
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...
of the fox squirrel
Fox Squirrel
The fox squirrel is the largest species of tree squirrel native to North America...
.
Background
The Delmarva fox squirrel also known as the eastern fox squirrel or Sciurus niger cinereus, is an endangered subspecies of fox squirrel. Its historical range included the Delmarva PeninsulaDelmarva Peninsula
The Delmarva Peninsula is a large peninsula on the East Coast of the United States, occupied by most of Delaware and portions of Maryland and Virginia...
, southeastern Pennsylvania and southern New Jersey, but its natural occurrence is now limited to parts of the Eastern Shore of Maryland and Virginia. In these areas the Delmarva fox squirrel's habitat has been degraded and its survivability rates have decreased. It has, however, been successfully reintroduced in other parts of its historical range.
Like all fox squirrels, the Delmarva fox squirrel has a full, fluffy tail. The Delmarva fox squirrel is frosty silver to slate gray with a white belly and can grow to be 75 centimetres (29.5 in) long, including up to 38 centimetres (15 in) of tail. They weigh around three pounds.
The Delmarva fox squirrel like many squirrel species, use trees to elude predators. Their preferred habitat is mature forest of both hardwood
Hardwood
Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...
and pine trees with an open understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
. An open understory within the forest is needed for the squirrels to successfully feed on nuts and seeds of the many trees such as oaks, hickories, sweet gum, walnut, and loblolly pine during the fall season when these trees are dispersing their seeds. In the summer and early fall they often feed on mature green pine cones. Other less important food sources include bud
Bud
In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of the stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be specialized to develop flowers or short shoots, or may have...
s, fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
, insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, and grain
GRAIN
GRAIN is a small international non-profit organisation that works to support small farmers and social movements in their struggles for community-controlled and biodiversity-based food systems. Our support takes the form of independent research and analysis, networking at local, regional and...
.
These fox squirrels prefer to make their dens in the hollows of trees. However, they will also make a nest of leaves and twigs in the crotch of a tree, in a tangle of vines on a tree trunk, or near the end of a large branch.
Mating
Mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
occurs in late winter and early spring. Gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
is about 44 days, with most young born between February and April. Litters average 1-6 young, which the female raises by herself.
Over the past several years the populations of Delmarva fox squirrels have been declining rapidly and in 1967 the U.S. Fish and Wildlife Service listed them as an endangered species.
Conservation
The Delmarva fox squirrel was listed as an endangered speciesEndangered 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...
by the U.S. Fish and Wildlife Service in 1967. A recovery plan was developed in 1979 and revised in 1983 and 1993. A principal strategy for species recovery is protection of its habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
.
The Delmarva fox squirrel was listed as an endangered species in 1967 because only 10% of their historical population was remaining. The cause of their significant decline in individuals was due to overhunting and habitat loss or destruction. Habitat destruction has been influenced by timber harvesting and farm land production. Housing developments, roads and increased commercial property are some other major factors for the continued loss of habitat. Along with human induced causes, predation plays a large role in the decline of numbers. Red and gray foxes, weasels, minks, eagles and other animals are the cause of high predation rates as the Delmarva Fox Squirrel’s habitat is within their range.
Many efforts have been made to restore habitat and increase the number of Delmarva fox squirrels within their historical range.
In 1979, the first recovery plan was developed to protect the habitat and increase the population of the Delmarva fox squirrel (. In completing this plan, the biologists projected that the habitat would become more suitable to the lifestyle of the squirrels as well as other animals that share the same habitat. The plan consisted of 11 sites in Maryland that attempted to reintroduce between 8 and 42 individuals within a 1-3 year process. At each site the same number of males and females were released to assess the reproduction rates and survivability of each sex. Many tests were done after reintroduction by live trapping and recruitment within 9 of the overall 11 sites.
In a more recent conservation effort many private and publicly owed lands were used to serve as habitat restoration areas. Private lands within the Delmarva fox squirrel range constitute for ~87% of the entire historical range of the DFS, while only 13% is of public land. A relationship between both public and private land owners allowed habitat restoration to occur in the 1990s. Different techniques were used by the Chesapeake Bay/Susquehanna River Ecoteam on public lands to monitor and reintroduce the Delmarva fox squirrel. Many private land owners also contributed to the restoration process by allowing biologists to assess their land.
Within the recovery plan made in the late 1970s, the idea of translocations was a prominent tool used to increase the population of the Delmarva fox squirrel. The most recent effort allowed for trapping and relocation of the Delmarva fox squirrel to different habitats that would allowed them to survive. The major goal was to reduce the probability of extinction, restore ecological diversity, and broaden the involvement of many areas in conservation effort. 83 squirrels were used in this effort and they were all radio-collared for post release tracking. The radio collars let biologists study the range and movements of the squirrels and tracked the distance traveled within a certain time period.
The Delmarva fox squirrel conservation effort has been an increasing success. The population within the historical range has increased and the many efforts have allowed for the habitats to become bettered suited for the Delmarva fox squirrel. Many issues have threatened the DFS with extinction but continued work to restore habitat must be done in order for this species to have a sustainable population and for the Delmarva Fox Squirrels to be released from the Endangered Species List.
External links
- Delmarva fox squirrel, Sciurus niger cinereus, U.S. Fish and Wildlife Service, Chesapeake Bay Field Office
- Delmarva Fox Squirrel, Maryland Department of Natural Resources