East urals radioactive trace: Adaptive strategy of rodents’ population

Abstract

Abstract. Population of small rodents in radiocontaminated environment is compelled to include more energy-intensive way of maintenance its ability to live -increasing of the proportion of mature young of the year (first pathway of ontogeny). Their reproductive characteristics -actual fecundity was higher, whereas embryonic mortality and the proportion of females with embryonic losses were significantly lower compared with neighboring areas. Abundance of mice in the impact zone was higher, age cross was revealed, which improves the adaptive possibility of the population. Preconditions for acceleration of evolutionary transformations of a population are created, but this process is restrained by both the local configuration of the polluted territory and migration of murine rodents. As a consequence, the population decreases the probability that certain changes will be fixed and inherited in a series of generations. Chronic low-dose radiation (stress) can be considered as the mechanism of switching of life history of cyclomorphic mammals. Thus, ontogenetic multiversality of small mammals is an important mechanism of protection strategy of population and decreasing the damaging action on biota in radiocontaminated environment. Functional approach makes it possible to reduce errors in assessing the radiological consequences and hence, can provide a reliable methodological basis for organization of biological monitoring.

Ecological effects of exposure to enhanced levels of ionizing radiation

“…Populations of pigmy wood mice (Sylvaemus uralensis Pall.) within the EURT have more males with higher fecundity, whereas embryonic mortality and the proportion of females with embryonic losses were significantly lower in comparison with uncontaminated areas (Grigorkina and Olenev, 2011). A significant increase in fertility, fecundity and maturation rate in comparison with control animals were revealed in root vole (Microtus oeconomus Pall.)…”

Stress-associated radiation effects in pygmy wood mouseApodemus uralensis(Muridae, Rodentia) populations from the East-Urals Radioactive Trace

“…Based on our own observations and the long-term monitoring of mouse-like rodent populations in the EURT zone (Grigorkina et al, 2008;Grigorkina & Olenev, 2013), an abundance of animals from 1 to 15 ind./100 trap-day was considered a small population size, from 15 to 30 ind./100 trap-day was a medium population size, and above 30 ind./100 trap-day was a large population size.…”