scholarly journals Effects of litter size on pup defence and weaning success of neighbouring bank vole females

2002 ◽  
Vol 80 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Pernilla Jonsson ◽  
Jep Agrell ◽  
Esa Koskela ◽  
Tapio Mappes
Keyword(s):  
Reproductive Success ◽  
Body Mass ◽  
Litter Size ◽  
Bank Vole ◽  
Dominance Rank ◽  
The Other ◽  
Clethrionomys Glareolus ◽  
Bank Voles ◽  
Litter Size Manipulation

Reproductive success of territorial female mammals depends partly on their capability to defend their young from conspecific intruders. However, how this is related to the characteristics of females and their litter sizes is largely unknown. The defence activity of 25 female bank voles (Clethrionomys glareolus) in relation to the number of offspring was studied in a behavioural arena by manipulating litter sizes (–2 pups or +2 pups). Infanticidal male bank voles were used as intruders–predators. Moreover, the weaning success (weaned at least one offspring or none) of 15 pairs of neighbouring females was investigated in a large indoor runway system. In each pair of females, the litter size of one female was reduced (–2 pups) and the litter size of the other enlarged (+2 pups). Defence activity of females increased with the number of offspring and the mother's size. However, weaning success of neighbours was related only to their body mass, and litter-size manipulation did not affect weaning success. Present results indicate that, although bank vole females increase their defence intensity with an increase in the number of pups, the weaning success of neighbouring females may be primarily determined by their size and dominance rank.

Relation between fertility and adrenal growth after mating in the bank vole, Clethrionomys glareolus

1981 ◽  
Vol 59 (3) ◽  
pp. 329-331
Author(s):  
Bertil Andersson ◽  
Torgny Gustafsson
Keyword(s):  
Bank Vole ◽  
The Other ◽  
Clethrionomys Glareolus ◽  
Adrenal Weight ◽  
Corpora Lutea ◽  
Bank Voles ◽  
The Relationship

The relationship between adrenal status and fertility in primiparous female bank voles, Clethrionomys glareolus, was examined. Out of 68 primiparous females, killed 4.5 or 6 days postcoitum, only 36 were pregnant. The pregnant ones had significantly larger adrenals than the nonpregnant ones. The nonpregnant females also had smaller ovaries, but the presence of corpora lutea proved that ovulation had occurred. Similarly, only 5 out of 11 females, mated with vasectomized males, were pseudopregnant with large corpora lutea, 6 days postcoitum. The remaining ones had ovaries similar to those in the other nonpregnant females. The pseudopregnant females had significantly larger adrenals than the nonpseudopregnant. This relationship between fertility and adrenal growth is unexpected, as in previous experiments an increase in adrenal weight has been shown to take place in direct reponse to mating, in the absence of ovaries and embryos.

Reproduction in a laboratory colony of bank vole, Clethrionomys glareolus

1980 ◽  
Vol 58 (6) ◽  
pp. 1016-1021 ◽  
Author(s):  
Torgny Gustafsson ◽  
Bertil Andersson ◽  
Lilian Westlin
Keyword(s):  
Litter Size ◽  
Bank Vole ◽  
Clethrionomys Glareolus ◽  
The Third ◽  
Bank Voles ◽  
Laboratory Colony ◽  
The Mean ◽  
Postpartum Estrus

Reproduction was studied in a laboratory colony of bank voles, Clethrionomys glareolus. Litter size was mainly dependent on parity, the mean being 4.3 in primiparous and 5.3 in multiparous females. Mortality of young during the nursing period was also affected by the order of litter, with a minimum in the third litter (14%). Most of this mortality took place during the first 3 days after birth. Gestation was 18.3 days in primiparous females. Postpartum estrus and mating was usual and the length of the resulting pregnancy was prolonged by lactation (19.1 days for zero sucklings vs. 22 days for four or more sucklings).

Determinants of reproductive success in voles: space use in relation to food and litter size manipulation

2002 ◽  
Vol 16 (5) ◽  
pp. 455-467 ◽  
Author(s):  
Pernilla Jonsson ◽  
Tommi Hartikainen ◽  
Esa Koskela ◽  
Tapio Mappes
Keyword(s):  
Reproductive Success ◽  
Litter Size ◽  
Space Use ◽  
Litter Size Manipulation

Adrenal growth during pregnancy in the bank vole, Clethrionomys glareolus: initiation by mating

1980 ◽  
Vol 58 (8) ◽  
pp. 1458-1461
Author(s):  
Torgny O. Gustafsson ◽  
C. Bertil Andersson
Keyword(s):  
Bank Vole ◽  
Ovarian Hormones ◽  
Clethrionomys Glareolus ◽  
Adrenal Weight ◽  
Induced Ovulation ◽  
Bank Voles

The relative roles of mating and the ovary in the initiating of adrenal growth in pregnant bank voles, Clethrionomys glareolus, were studied. In one experiment females were ovariectomized shortly after mating; 4 days later they had significantly heavier adrenals than unmated, ovariectomized controls. In another experiment females were ovariectomized and brought into oestrus by oestradiol- 17β injections. Half of the females were mated and after 4 days their adrenals were significantly larger than those of unmated controls. We conclude that the increase in adrenal weight during pregnancy in bank voles is triggered directly by mating, without involvement of ovarian hormones. The mechanism is suggested to be a neuroendocrine reflex, acting via the hypothalamus and the pituitary. The mechanism may be the same as that involved in the induced ovulation in this species.

Initiation of breeding after winter in bank voles: effects of food and population density

2001 ◽  
Vol 79 (10) ◽  
pp. 1743-1753 ◽  
Author(s):  
Jana A Eccard ◽  
Hannu Ylönen
Keyword(s):  
Population Density ◽  
Bank Vole ◽  
Local Density ◽  
Local Population ◽  
Food Supplements ◽  
Clethrionomys Glareolus ◽  
Environmental Stability ◽  
Food Treatment ◽  
Bank Voles ◽  
Winter Food

We studied factors causing variation in the initiation of reproduction after winter in the bank vole (Clethrionomys glareolus), an iteroparous seasonal breeder, by offering different winter food supplements and monitoring local density variation. We used either sunflower seeds or barley to supplement the diet of populations of bank voles in grassland enclosures. In a parallel experiment we used spruce seeds, a natural winter food, to supplement the diet of bank vole populations in unfenced spruce forest. Survival, maturation, and breeding were monitored by livetrapping. Population density decreased during winter in grassland enclosures and remained constant in the forest, with no difference between food treatments. Breeding was initiated earlier in the grassland enclosures than in the forest, probably because of the supplemental food supply in both seed treatments and social and environmental stability in enclosures. Within both experiments, we found no differences in timing of parturition between food treatments. Inter actions of food treatment with density of females influenced the time of initiation of breeding in both experiments. At low densities, breeding started up to 1 month earlier than the population average. At high densities, a proportion of females did not breed during spring. Massive food supplements advanced the initiation of breeding, but among animals with similar food supplies, local population density seemed to have stronger regulatory effects. Local density variations may therefore create asynchronous breeding patterns within populations under similar wintering conditions.

Body mass influences maternal allocation more than parity status for a long-lived cervid mother

2019 ◽  
Vol 100 (5) ◽  
pp. 1459-1465 ◽  
Author(s):  
Eric S Michel ◽  
Stephen Demarais ◽  
Bronson K Strickland ◽  
Jerrold L Belant ◽  
Larry E Castle
Keyword(s):  
Reproductive Success ◽  
Body Mass ◽  
Litter Size ◽  
Reproductive Value ◽  
Lifetime Reproductive Success ◽  
Reproductive Tactics ◽  
High Quality ◽  
Maternal Body ◽  
Individual Offspring ◽  
Maternal Allocation

Abstract Mothers should balance the risk and reward of allocating resources to offspring to optimize the reproductive value of both offspring and mother while maximizing lifetime reproductive success by producing high-quality litters. The reproductive restraint hypothesis suggests maternal allocation should peak for prime-aged mothers and be less for younger mothers such that body condition is not diminished to a level that would jeopardize their survival or future reproductive events. We assessed if reproductive tactics varied by maternal body mass and parity status in captive female white-tailed deer (Odocoileus virginianus) to determine if prime-aged mothers allocate relatively more resources to reproduction than primiparous mothers. Maternal body mass, not parity status, positively affected maternal allocation, with heavier mothers producing both heavy litters and heavy individual offspring. Conversely, maternal body mass alone did not affect litter size, rather the interaction between maternal body mass and parity status positively affected litter size such that maternal body mass displayed a greater effect on litter size for primiparous than multiparous mothers. Our results suggest that heavy white-tailed deer mothers allocate additional resources to current year reproduction, which may be an adaptation allowing mothers to produce high-quality litters and increase their annual reproductive success because survival to the next reproductive attempt is not certain.

Sterile matings initiate the breeding season in the bank vole, Clethrionomys glareolus. A field and laboratory study

1982 ◽  
Vol 60 (3) ◽  
pp. 387-391 ◽  
Author(s):  
Lilian M. Westlin ◽  
Erik Nyholm
Keyword(s):  
Male Sterility ◽  
Breeding Season ◽  
Laboratory Study ◽  
Bank Vole ◽  
Laboratory Experiments ◽  
Clethrionomys Glareolus ◽  
Bank Voles ◽  
Young Of The Year

The start of the breeding season of overwintered female bank voles, Clethrionomys glareolus, and also the start of breeding in young of the year, was characterized by a general occurrence of sterile ovulations. Similarly, in laboratory experiments, 23 out of 42 young virgin females failed to become pregnant after the first mating, and often mated several times before becoming pregnant. The experiments indicated that the sterile ovulations were attributed to temporary sterility of the females during maturation either at adolescence or at the beginning of the new breeding season, and not a result of (1) initial ovulations of the season being spontaneous, (2) male sterility, or (3) male-induced pregnancy blockage.

Sign in / Sign up

Export Citation Format

Share Document