Effects of seasonal, ontogenetic, and genetic factors on lifespan of male and female progeny of Arvicola amphibius

Abstract

The water vole (Arvicola amphibius) in the forest-steppe of West Siberia is known to have wide fluctuations in abundance. These fluctuations are accompanied by changes in birth and death rates, sex-age structure of the population, and individual morphophysiological and behavioral characteristics of the animals. Survival of the animals depends on season, phase of population cycle, and sex. Based on the data of long-term captive breeding of water voles, the maximal lifespan of males was found to be 1188 days and that of females, 1108 days. There were no differences between the sexes in mean lifespan. The probability of living 2 years or longer was 0.21. Individuals who began breeding at an older age had a significantly longer lifespan and produced more offspring. The survival curves of the spring-born animals were steeper than of those summer-/autumn-born. Maternal factors had a differential effect on males and females with respect to lifespan. Male lifespan correlated negatively with maternal age, parity, and litter size, whereas female lifespan did not correlate with these characteristics. To estimate heritability, parent-offspring correlations of lifespan were calculated, as well as full-sib intraclass correlations. No statistically significant correlation was found for lifespan between sons and mothers, sons and fathers, and daughters and fathers. Daughters' lifespan correlated positively with maternal lifespan (r = 0.21, p < 0.001). Female full-sibs and male full-sibs had the same intraclass correlations, 0.22, p < 0.001.

Population dynamics of an island population of water voles Arvicola amphibius (Linnaeus, 1758) with one major predator, the eagle owl Bubo bubo (Linnaeus, 1758), in northern Norway

“…A litter of 4.5 young at 5 g/young is 22.5 g (Stoddart 1971;Nazarova 2013), easily accounting for the weight difference between females and males in summer. Many males also lost mass during the summer, due to the costs of searching and fighting for females (Frafjord 2016).…”

“…Many males also lost mass during the summer, due to the costs of searching and fighting for females (Frafjord 2016). Females should theoretically be able to produce 3-4 litters during May-July (sensu Stoddart 1971;Nazarova 2013), but the demands of reproduction may have increased the risk of being predated. This fact alone could explain the modest population increase of maximum 3.5 times during the summer on Trolløya.…”

“…Because animals with larger body size in general tend to have slower individual and population growth rates, size may at least potentially affect the length of the population cycle (Krebs 2013). In captivity, female and male water voles had a mean lifespan of 368 and 393 days, with maximum 1100-1200 days (Nazarova 2013). Litter size at birth was around 4.3 and females had around four litters in their lifespan.…”

“…Litter size at birth was around 4.3 and females had around four litters in their lifespan. Young born in spring could reproduce in the summer, but not those born later (Nazarova 2013). Food availability may influence water vole growth rates and mass at sexual maturity, and increased density may reduce maturation rates (Moorhouse et al 2008).…”

From theories of aging to anti-aging interventions

“…Novoseltsev and Novoseltseva ( 2013 ) used mathematical approaches to assess the origin of stochasticity in Drosophila reproduction, in relation to life expectancy. To add to mathematical predictions, analysis of long-term captive breeding of water voles demonstrated that individuals who began breeding at an older age had a significantly longer lifespan and produced more offspring (Nazarova, 2013 ).…”