Timing of Major Life Events
The breeding season of northern red-backed voles generally extends from May to August. Females are polyestrous and produce two or three litters during the breeding season. The first litter is produced in late May or early June.
Litter size ranges from four to nine. The average litter size is 5.93. Young northern red-backed voles are unable to regulate their temperature successfully until about 18 days. At this time they are weaned and leave the nest. Young grow little during the winter because of low food supplies. Age of sexual maturity depends to some extent on time of birth. About 20% of females from the first litter breed during the summer of birth. The remaining 80%, and later litters, breed the following May. Martell and Fuller found that the onset of summer breeding was related to the time of snowmelt. A late spring was followed by a low rate of maturation of young-of-the-year females.
In dense populations of northern red-backed voles, sexual maturation of young females may be delayed, or they may migrate to a vacant breeding space.
Northern red-backed voles are mainly nocturnal and crepuscular but are of necessity about during the prolonged arctic daylight season.
Read more about this topic: Northern Red-backed Vole
Famous quotes containing the words timing, major, life and/or events:
“Is it a new spring star
Within the timing chill,
Talking, or just a mime,
That rises in the blood
Thin Jack-and-Jilling seas
Without the human will?”
—Allen Tate (1899–1979)
“When I see that the nineteenth century has crowned the idolatry of Art with the deification of Love, so that every poet is supposed to have pierced to the holy of holies when he has announced that Love is the Supreme, or the Enough, or the All, I feel that Art was safer in the hands of the most fanatical of Cromwell’s major generals than it will be if ever it gets into mine.”
—George Bernard Shaw (1856–1950)
“The animal is one with its life activity. It does not distinguish the activity from itself. It is its activity. But man makes his life activity itself an object of his will and consciousness. He has a conscious life activity. It is not a determination with which he is completely identified.”
—Karl Marx (1818–1883)
“It is clear to everyone that astronomy at all events compels the soul to look upwards, and draws it from the things of this world to the other.”
—Plato (c. 427–347 B.C.)