Seasonal Variation in Litter Size of the Meadow Vole in Southern Ontario

1963 ◽  
Vol 44 (4) ◽  
pp. 467 ◽  
Author(s):  
Edward Kott ◽  
William L. Robinson
Keyword(s):  
Seasonal Variation ◽  
Litter Size ◽  
Meadow Vole ◽  
Southern Ontario

scholarly journals MATERNAL AGE DRIVES SEASONAL VARIATION IN LITTER SIZE OF PEROMYSCUS LEUCOPUS

10.1644/013 ◽  
2004 ◽  
Vol 85 (5) ◽  
pp. 940-947 ◽  
Author(s):  
M. A. Havelka ◽  
J. S. Millar
Keyword(s):  
Seasonal Variation ◽  
Litter Size ◽  
Maternal Age ◽  
Peromyscus Leucopus

Pig melatonin receptor 1a (MTNR1A) genotype is associated with seasonal variation of sow litter size

2009 ◽  
Vol 115 (1-4) ◽  
pp. 317-322 ◽  
Author(s):  
O. Ramírez ◽  
A. Tomàs ◽  
C. Barragan ◽  
J.L. Noguera ◽  
M. Amills ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Litter Size ◽  
Melatonin Receptor

Control of Small Mammals on a Hardwood Plantation by Poison-Bait Feeders

1977 ◽  
Vol 53 (2) ◽  
pp. 96-99
Author(s):  
Arthur M. Martell ◽  
Andrew Radvanyi
Keyword(s):  
Small Mammals ◽  
Microtus Pennsylvanicus ◽  
Meadow Vole ◽  
Low Density ◽  
Meadow Voles ◽  
Southern Ontario

Poison-bait feeder stations were placed on a hardwood plantation in southern Ontario in 1973 to attempt long-term control of a meadow vole (Microtus pennsylvanicus) population by continuous dispensing of poisoned grain. Baiting by means of feeders successfully reduced the numbers of meadow voles and maintained them at a low density, about 3-6/ha (1.2-2.4/acre), through April 1976. During the same period, the density of meadow voles on surrounding unpoisoned areas declined from a 1973 peak to about the same as that found on the poisoned plot by fall and winter 1975-76. Despite that low density, less than 4/ha (1.6/acre), severe gnawing and girdling of young hardwoods occurred during winter. Poison-bait feeders are efficient at reducing meadow vole populations from high to low density, but it cannot be assumed that even those low-density populations will not damage hardwood plantations.

scholarly journals Seasonal variation in the litter size in relation with variations in the ovulation rate and the embryo mortality in the sow

1981 ◽  
Vol 30 (3) ◽  
pp. 383-383
Author(s):  
Françoise MARTINAT-BOTTE ◽  
P. DANDO ◽  
J. GAUTIER ◽  
M. TERQUI
Keyword(s):  
Seasonal Variation ◽  
Litter Size ◽  
Ovulation Rate ◽  
Embryo Mortality

Parental behaviour of prairie voles (Microtus ochrogaster) and meadow voles (M. pennsylvanicus) in relation to sex of offspring

Behaviour ◽  
2014 ◽  
Vol 151 (4) ◽  
pp. 535-553 ◽  
Author(s):  
Betty McGuire ◽  
William E. Bemis ◽  
Francoise Vermeylen
Keyword(s):  
Litter Size ◽  
Female Offspring ◽  
Prairie Vole ◽  
Microtus Ochrogaster ◽  
Meadow Vole ◽  
Prairie Voles ◽  
Meadow Voles ◽  
Male And Female ◽  
Mothers And Fathers ◽  
Offspring Sex

Monogamous parents are predicted to invest equally in male and female offspring whereas polygynous parents in good condition are predicted to invest more in male than female offspring. Sex-biased parental investment can occur in three ways: (1) mothers and fathers invest different amounts of care in their offspring (effect of parent sex); (2) parents invest different amounts of care in male and female offspring (effect of offspring sex); and (3) one parent, but not the other, invests different amounts of care in male and female offspring (interaction between parent sex and offspring sex). Studies of parent–offspring interactions in rodents have focused on either effect of parent sex or effect of offspring sex, but not the interaction between parent sex and offspring sex, and most studies have examined only one species. We studied prairie voles (Microtus ochrogaster), a monogamous species, and meadow voles (M. pennsylvanicus), a polygynous (or promiscuous) species, under laboratory conditions designed to simulate field conditions. For each species, we recorded the frequency and duration with which mothers and fathers licked their male and female offspring. We found that meadow vole fathers licked male offspring for longer durations than female offspring. However, prairie vole fathers, prairie vole mothers, and meadow vole mothers did not lick male and female pups for different durations. From the standpoint of the pups, male prairie vole pups, female prairie vole pups, and female meadow vole pups were licked for longer durations by their mothers than by their fathers. In contrast, for male meadow vole pups there was no difference in the duration with which they were licked by mothers and fathers. We also detected effects of litter size: as litter size increased, the frequency and duration of pup licking decreased for mothers and increased for fathers. For duration (but not frequency) of pup licking, these changes were more dramatic in meadow voles than in prairie voles. Our data are generally consistent with predictions that monogamous parents, such as prairie voles, should invest equally in male and female offspring whereas polygynous (or promiscuous) parents, such as meadow voles, should invest more in male offspring when conditions are favourable. Our data also highlight the complexity of parent–offspring interactions in rodents and emphasize the need to examine whether male and female offspring within a species differ in their behaviour or ability to obtain parental care.

scholarly journals Studies on the Sex-Ratio and Related Phenomena

1926 ◽  
Vol 4 (1) ◽  
pp. 93-104
Author(s):  
A. S. PARKES
Keyword(s):  
Seasonal Variation ◽  
Sex Ratio ◽  
Recent Work ◽  
Litter Size ◽  
Annual Variation ◽  
Average Litter Size ◽  
Average Size

(1) 1872 normal mice bred during November 1922-October 1925 had an average litter-size of 6.18, and a male percentage of 51.7 ± .77, both of which figures are lower than the corresponding ones found for 1921-2. (2) The annual variation in the sex-ratio is, however, not very appreciable, the figures for the four years running 54.2 ± 1.04, 50.4 ± 3.22, 52.2 ± 1.18, 51.4 ± 1.09. The average size of litter during these four periods ranged from 6.65 to 5.93. (3) Considerable seasonal variation in both fertility and sex-ratio occurred, the highest figures being fertility 6.46 and male percentage 55.9 ± 1.83 in the October-December quarter, and the lowest being fertility 5.82 and male percentage 48.2 ± 1.46 in the April-June period. (4) Litter-size appeared to be uncorrelated with any sort of definite variation in the sex-ratio. (5) Recent work on the mouse is discussed.

scholarly journals Demography of Microtus pennsylvanicus in Southern Ontario: enumeration versus Jolly–Seber estimation compared

1985 ◽  
Vol 63 (5) ◽  
pp. 1174-1180 ◽  
Author(s):  
Rudy Boonstra
Keyword(s):  
Population Size ◽  
Breeding Season ◽  
Survival Rates ◽  
Microtus Pennsylvanicus ◽  
Meadow Vole ◽  
Vole Population ◽  
Maternal Condition ◽  
Southern Ontario ◽  
Almost All

A meadow vole population near Toronto went through a cycle in numbers from July 1978 to May 1982. The population never reached a density less than 96 voles/ha or greater than 630 voles/ha. Jolly–Seber estimates differed from total enumeration counts by an average of 10.6% in population size and by less than 0.03 per 2 weeks in survival rates for almost all periods. Sharp spring declines occurred in both sexes in both the increase and the peak years, but only among females in the decline year. Dispersal occurred more frequently during the spring of the increase and peak than of the decline, was associated with maturation, and was biased towards males. The breeding season lasted 9 months in the increase and decline but only 5 months in the peak. Survival of adults during the decline summer was no different from that in other years. Survival of young during the increase and peak was moderately high, but was extremely poor during the decline. Since most young failed to be captured in either pitfalls or live-traps, I conclude that they died shortly before or after weaning and suggest that maternal condition was impaired by prior events in the peak and that this may apply to other cyclic microtine populations.

scholarly journals Meteorological Influences on Seasonal Variation of Fine Particulate Matter in Cities over Southern Ontario, Canada

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Jane Liu ◽  
Siliang Cui
Keyword(s):  
United States ◽  
Particulate Matter ◽  
Seasonal Variation ◽  
Fine Particulate Matter ◽  
The United States ◽  
Northern Region ◽  
Southern Ontario ◽  
Fine Particulate ◽  
Meteorological Influences ◽  
Midlatitude Cyclones

This study examines meteorological impacts on seasonal variation of fine particulate matter (PM2.5) in southern Ontario, Canada. After analyzing PM2.5data at 12 cities in the region in 2006, we found that PM2.5concentrations were 30–40% higher in summer (7–15 μg/m3) than in winter (4–11 μg/m3). High PM2.5episodes occurred more frequently in warmer seasons. Analyses of surface meteorology, weather maps, and airflow trajectories suggest that these PM2.5episodes were often related to synoptic transport of pollutants from highly polluted areas in the United States. The southerly or southwesterly winds associated with midlatitude cyclones play an important role in such transport. A typical weather pattern favoring the transport is suggested. When it was hot, humid, and stagnant with southerly or southwesterly winds, the likelihood of high PM2.5occurrences was high. The Greater Golden Horseshoe and Southwestern Ontario regions had higher PM2.5(6–12 μg/m3annually) than the northern region (4–6 μg/m3), reflecting combined effects of meteorology, regional transport, and local emissions. In the future, PM2.5transport from the United States will likely increase in abundance because of possible prolonged accumulation at the pollution sources as the frequency of the midlatitude cyclones may reduce under climate change.

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