Wood mouse
Encyclopedia
The wood mouse is a common murid rodent
from Europe and northwestern Africa. It is closely related to the yellow-necked mouse
(Apodemus flavicollis) but differs in that it has no band of yellow fur around the neck
, has slightly smaller ears, and is usually slightly smaller overall: around 90 mm (3.54") in length. It is found across most of Europe and is a very common and widespread species, is commensal with people and is sometimes considered a pest. Other common names are long-tailed field mouse, field mouse, common field mouse, and European wood mouse.
, a decrease in physiological activity. They are mainly active during the dark, and are very good climbers. While foraging, wood mice pick up and distribute visually conspicuous objects, such as leaves and twigs, which they then use as landmarks during exploration. If a wood mouse is caught by its tail, it can quickly shed the end of it, which may never regrow. The wood mouse does not hibernate
and, despite its name, it prefers hedgerows to woodland
. In order to prevent predation, wood mice tend to forage in covered microsites.
The wood mouse has a breeding season
from February to October in which multiple matings occur between males and females resulting in scramble competition. Such behavioral characteristics result in sperm competition
and multiple paternity litters. The society is polygynous
with copulation resulting from scramble competition during reproductive periods. Males possess a sac known as the cauda epididymus which stores sperm and lies underneath the scrotum
protrusion. Temperature regulation ensures maximum sperm output.
One interesting observation about the species, in particular the males, is the morphology of the spermatozoa. They develop falciform (sickle shaped) heads after meiosis
and before spermiation (release during ejaculation
). The hook located at the tip of the head adheres to the surface of the head prior to deployment. Propidium iodide staining revealed that only the basal surface of the hook is of nuclear origin. These apical hooks are deployed in female reproductive tract (mechanism responsible involved the remodeling of actin filaments in the hook). Deployed apical hooks combine with apical hooks and flagella of other spermatozoa. The aggregates of spermatozoa that result form "mobile trains", which have experimentally been determined to possess better motility in the female reproductive tract. The mobility of these mobile trains was also found to be influenced by premature acrosome reactions, altruistic
acts performed by some spermatozoa for the benefit of other genetically similar gametocyte
s. This altruism follows a "green beard
" mechanism in which spermatozoa discern the genetic similarity of surrounding gametocytes (such mechanisms are rare because they must code for a recognizable phenotype as well as response mechanisms). Once spermatozoa of similar genotypes are identified, altruism genes are turned on to elicit a response that seeks to conserve the genes present in the other cell, even if it results in the destruction of the cell performing the action.
The gestation
period of wood mice is of 25–26 days and each female produces on average five young. The offspring become independent after about three weeks and become sexually active after two months.
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....
from Europe and northwestern Africa. It is closely related to the yellow-necked mouse
Yellow-necked mouse
The Yellow-necked Mouse Apodemus flavicollis is closely related to the wood mouse, with which it was long confused, only being recognised as a separate species in 1894. It differs in its band of yellow fur around the neck and in having slightly larger ears and usually being slightly larger overall....
(Apodemus flavicollis) but differs in that it has no band of yellow fur around the neck
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
, has slightly smaller ears, and is usually slightly smaller overall: around 90 mm (3.54") in length. It is found across most of Europe and is a very common and widespread species, is commensal with people and is sometimes considered a pest. Other common names are long-tailed field mouse, field mouse, common field mouse, and European wood mouse.
Habitat
Wood mice inhabit forests, grasslands, and cultivated fields. Almost entirely nocturnal and terrestrial, wood mice burrow extensively, build nests of plants and live in buildings during harsh seasons. It is one of the most intensively studied species in the genus. In Europe it ranges north to Scandinavia and east to Ukraine. The wood mouse is also found in northwestern Africa and on many Mediterranean islands.Behaviour
Wood mice are primarily seed eaters, particularly seeds of trees such as oak, beech, ash, lime, hawthorn and sycamore. If there is a plentiful amount of seeds on the ground, they carry them back to their nests/burrows for storage. They may eat small invertebrates such as snails and insects, particularly in late spring and early summer when seeds are least available. They also consume berries, fruits and roots. They do not hibernate; however, during severe winter seasons they fall into a sort of torporTorpor
Torpor, sometimes called temporary hibernation is a state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and rate of metabolism. Animals that go through torpor include birds and some mammals such as mice and bats...
, a decrease in physiological activity. They are mainly active during the dark, and are very good climbers. While foraging, wood mice pick up and distribute visually conspicuous objects, such as leaves and twigs, which they then use as landmarks during exploration. If a wood mouse is caught by its tail, it can quickly shed the end of it, which may never regrow. The wood mouse does not hibernate
Hibernation
Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...
and, despite its name, it prefers hedgerows to woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
. In order to prevent predation, wood mice tend to forage in covered microsites.
Reproduction
Breeding season
The breeding season is the most suitable season, usually with favourable conditions and abundant food and water, for breeding among some wild animals and birds . Species with a breeding season have naturally evolved to have sexual intercourse during a certain time of year in order to achieve the...
from February to October in which multiple matings occur between males and females resulting in scramble competition. Such behavioral characteristics result in sperm competition
Sperm competition
Sperm competition is a term used to refer to the competitive process between spermatozoa of two different males to fertilize an egg of a lone female. Competition occurs whenever females engage in promiscuous mating to increase their chances in producing more viable offspring...
and multiple paternity litters. The society is polygynous
Polygyny
Polygyny is a form of marriage in which a man has two or more wives at the same time. In countries where the practice is illegal, the man is referred to as a bigamist or a polygamist...
with copulation resulting from scramble competition during reproductive periods. Males possess a sac known as the cauda epididymus which stores sperm and lies underneath the scrotum
Scrotum
In some male mammals the scrotum is a dual-chambered protuberance of skin and muscle containing the testicles and divided by a septum. It is an extension of the perineum, and is located between the penis and anus. In humans and some other mammals, the base of the scrotum becomes covered with curly...
protrusion. Temperature regulation ensures maximum sperm output.
One interesting observation about the species, in particular the males, is the morphology of the spermatozoa. They develop falciform (sickle shaped) heads after meiosis
Meiosis
Meiosis is a special type of cell division necessary for sexual reproduction. The cells produced by meiosis are gametes or spores. The animals' gametes are called sperm and egg cells....
and before spermiation (release during ejaculation
Ejaculation
Ejaculation is the ejecting of semen from the male reproductory tract, and is usually accompanied by orgasm. It is usually the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. In rare cases ejaculation occurs because of prostatic disease...
). The hook located at the tip of the head adheres to the surface of the head prior to deployment. Propidium iodide staining revealed that only the basal surface of the hook is of nuclear origin. These apical hooks are deployed in female reproductive tract (mechanism responsible involved the remodeling of actin filaments in the hook). Deployed apical hooks combine with apical hooks and flagella of other spermatozoa. The aggregates of spermatozoa that result form "mobile trains", which have experimentally been determined to possess better motility in the female reproductive tract. The mobility of these mobile trains was also found to be influenced by premature acrosome reactions, altruistic
Altruism
Altruism is a concern for the welfare of others. It is a traditional virtue in many cultures, and a core aspect of various religious traditions, though the concept of 'others' toward whom concern should be directed can vary among cultures and religions. Altruism is the opposite of...
acts performed by some spermatozoa for the benefit of other genetically similar gametocyte
Gametocyte
A gametocyte is a eukaryotic germ cell that divides by mitosis into other gametocytes or by meiosis into gametids during gametogenesis. Male gametocytes are called spermatocytes, and female gametocytes are called oocytes....
s. This altruism follows a "green beard
Green-beard effect
The gene-centered view of evolution postulates that natural selection will increase the frequency of those genes whose phenotypic effects ensure their successful replication...
" mechanism in which spermatozoa discern the genetic similarity of surrounding gametocytes (such mechanisms are rare because they must code for a recognizable phenotype as well as response mechanisms). Once spermatozoa of similar genotypes are identified, altruism genes are turned on to elicit a response that seeks to conserve the genes present in the other cell, even if it results in the destruction of the cell performing the action.
The 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 ....
period of wood mice is of 25–26 days and each female produces on average five young. The offspring become independent after about three weeks and become sexually active after two months.
External links
- Apodemus sylvaticus in the Smithsonian Museum of Natural History MSW Scientific Names
- Apodemus sylvaticus in the Catalogue of Life: 2007 Annual Checklist
- Apodemus sylvaticus in Fauna Europaea
- Apodemus sylvaticus in the Animal Diversity Web
- The wood mouse, an excellent article in French
- The market effect in the wood mouse, an excellent abstract of research done on grooming and reproduction in wood mouse