Search results for "Glare"
showing 10 items of 103 documents
Distinct bhaplotype structure at the innate immune receptor Toll-like receptor 2 across bank vole populations and lineages in Europe
2015
Abstract: Parasite-mediated selection may contribute to the maintenance of genetic variation at host immune genes over long time scales. To date, the best evidence for the long-term maintenance of immunogenetic variation in natural populations comes from studies on the major histocompatibility complex (MHC) genes, whereas evidence for such processes from other immune genes remains scarce. In the present study, we show that, despite pronounced population differentiation and the occurrence of numerous private alleles within populations, the innate immune gene Toll-like receptor 2 (TLR2) displays a distinct haplotype structure in 21 bank vole (Myodes glareolus) populations across Europe. Haplo…
Female bank voles ( Clethrionomys glareolus ) prefer dominant males; but what if there is no choice?
1996
Both intra-sexual competition between males and female mate choice have been found to affect mating behaviour in rodents. We studied female choice in the bank vole (Clethrionomys glareolus) under circumstances where male-male competition was excluded and the female could interact and mate freely with the males. Mating behaviour was observed in two situations: (1) the female encountered two males with a clear dominance relationship; and (2) the two males were equal in their social status. In all tests where a female in postpartum oestrus had a choice between males of different social rank she mated with the dominant one. When choosing between an even pair of males there was no difference in …
Behaviour of cyclic bank voles under risk of mustelid predation: do females avoid copulations?
1993
Mustelid odours have been shown to suppress breeding in captive bank voles (Clethrionomys glareolus) from cyclic populations (Ylonen 1989; Ylonen and Ronkainen 1994). The mechanism behind the suppression is unknown. Based on a series of behavioural trials and breeding experiments with pairs of bank voles in breeding condition, we suggest that the primary cause for breeding suppression is a change in female mating behaviour. Experimental female-male pairs (n=34) exposed to mustelid odour decreased their general activity compared to control pairs (n=34). When encountering males in behavioural trials, females exposed to stoat odour were more aggressive and actively avoided precopulatory behavi…
Data from: Temporal dynamics of Puumala hantavirus infection in cyclic populations of bank voles
2017
Understanding the dynamics of zoonotic pathogens in their reservoir host populations is a prerequisite for predicting and preventing human disease epidemics. The human infection risk of Puumala hantavirus (PUUV) is highest in northern Europe, where populations of the rodent host (bank vole, Myodes glareolus) undergo cyclic fluctuations. We conducted a 7-year capture-mark-recapture study to monitor seasonal and multiannual patterns of the PUUV infection rate in bank vole populations exhibiting a 3-year density cycle. Infected bank voles were most abundant in mid-winter months during years of increasing or peak host density. Prevalence of PUUV infection in bank voles exhibited a regular, seas…
Acs optiskās kvalitātes ietekme uz kontrastjutību un redzes asumu
2017
Darbs ir uzrakstīts angļu valodā uz 50 lapaspusēm, satur 37 figūras, 1 tabula un 41 literatūras avotus. Pētījuma mērķis bija novērtēt redzes kvalitāti dalībniekiem ar dažādām izmaiņām acs optiskajās vidēs. Augsta kontrasta redzes asums, mezopiskais redzes asums un kontrastjutība ir labi parametri acs optiskās kvalitātes novērtēšanai. Mezopiskais redzes asums ir ar augstu jutību, lai atklātu dalībniekus ar nelielas pakāpes apduļķojumiem acs optiskajās vidēs (agrīna katarakta). Kontrastjutības tests ir jutīgs uz izmaiņām acs optiskajās vidēs dalībniekiem ar ortokeratoloģijas lēcām. Augsta kontrasta redzes asums ir pietiekami jutīgs uz cita veida izmaiņām acs struktūrās
Changing female spacing behaviour and demography in an enclosed breeding population of Clethrionomys glareolus
1988
The social organization of Clethrionomys glareolus Schreber was studied by live trapping in an enclosure of 0.8 ha in Central Finland between the years 1982–1986. The enclosure consisted of three habitats: abandoned field, brushwood, and moist spruce heath forest. The population density increased from 50 voles ha−1 in 1982 and 1983 to 150 ha−1 in 1984 and 1985. In the summer of 1986 the population crashed to almost zero. In the summer of 1984 after winter breeding the number of breeding females grew to 22 compared with 6–7 in previous years. In 1984 the mature females changed from territorial to group behaviour. During the high population density in 1984 and 1985 breeding stopped already in…
Infanticide and Population Growth in the Bank Vole (Myodes glareolus): The Effect of Male Turnover and Density
2011
One major intrinsic factor affecting recruitment of young into a population is infanticide, the killing of conspecific young by adult males. It occurs in most mammal species, like our study species the bank vole (Myodes glareolus), and is widely accepted as an adaptive behavior, which may increase male fitness via nutritional gain, decreased competition, or an increased access to mates. A turnover of males in a population increases the risk of infanticide owing to a disruption of social structures. In a controlled field study, we tested the effects of total male turnover and density on juvenile recruitment and female space use in experimental bank vole populations. Juvenile recruitment decl…
Different demography of friends and strangers: an experiment on the impact of kinship and familiarity in Clethrionomys glareolus.
1989
We examined demographic effects of familiarity and relatedness in the bank vole Clethrionomys glareolus (Schreber) in four 0.5-ha enclosures in Central Finland. In two enclosures were mature voles which had overwintered together and some of their mature off-spring (hereafter referred to as “Friends”), and in the other two individuals of the same species captured from different localities near the study area (“Strangers”). The experiment lasted from June to September. The populations of Friends reached densities twice as high as those of Strangers with a significantly higher rate of recruitment and survival of the young. This may have been due to mutual familiarity decreasing antagonism towa…
Data from: Maintenance costs of male dominance and sexually antagonistic selection in the wild
2019
1. Variation in dominance status determines male mating and reproductive success, but natural selection for male dominance can be detrimental or antagonistic for female performance, and ultimately their fitness. Attaining and maintaining a high dominance status in a population of competing individuals is physiologically costly for males. But how male dominance status is mediated by maintenance energetics is currently not well understood, nor are the correlational effects of male energetics on his sisters recognized. 2. We conducted laboratory and field experiments on rodent populations to test whether selective breeding for male dominance status (dominant vs. subordinate breeding lines) ant…
Epigenetic mechanisms behind phenotypic changes in different population densities in bank voles (Myodes glareolus)
2017
Metsämyyrän (Myodes glareolus) fenotyyppisten muutosten epigeneettiset mekanismit eri populaatiotiheyksissä. Epigeneettisilla mekanismeilla on perustava rooli normaalissa geeniekspression aktiivisuudessa ja ne voidaan nähdä molekulaaristen prosessien systeeminä, joka reagoi ympäristötekijöihin ja säätelee geenisäätelyä muuttamatta alkuperäistä DNA-sekvenssiä. DNA-metylaatio on eniten tutkittu epigeneettinen mekanismi jolla on tärkeä rooli geenien säätelyssä normaalin solujen kehityksen aikana. Metylaatio ilmenee tyypillisesti CpG-dinukleotideissa, joissa metyyliryhmä kiinnittyy 5’-sytosiiniin (C) jota seuraava emäs on guaniini (G). Tämä voi estää näihin CpG-paikkoihin liittyvien geenien ilm…