Comparative demography of Peromyscus maniculatus and Microtus oregoni populations after logging and burning of coastal forest habitats

1980 ◽  
Vol 58 (12) ◽  
pp. 2252-2259 ◽  
Author(s):  
Thomas P. Sullivan

This study was designed to investigate the abundance and related demographic attributes of Peromyscus maniculatus and Microtus oregoni populations in successional burned and unburned cutover areas. These populations were livetrapped in three habitats at Maple Ridge, British Columbia, from March to October 1978. The average densities of deer mice and Oregon voles per hectare on the burned area were 27.6 and 11.6, and on two unburned areas were 19.1 and 16.0, and 21.9 and 10.4, respectively. There was little variation in the proportion of breeding animals among habitats for either species. Male deer mice survived better on the burned area than in either of the other two habitats; there was little variation in survival among females. Males and females of M. oregoni survived equally well. Deer mice generally had greater proportions of reproductive animals and survived better than Oregon voles on all study areas. However, juvenile voles had 1.7 times higher survival than young deer mice. Demographic parameters within populations of P. maniculatus and M. oregoni tend to be similar in successional burned and unburned habitats 4–5 years after logging.

1998 ◽  
Vol 32 (1) ◽  
pp. 55-64 ◽  
Author(s):  
V. Hayssen

In conjunction with establishing colonies of deer mice in the UK, effects of transportation on reproduction in agouti (A) and nonagouti (a) deer mice were assessed. Adults were shipped via ground courier and air freight from Northampton, Massachusetts, USA to Sutton Bonington, Leicestershire, England in February and June. Deer mice were paired upon arrival in Sutton Bonington, whereas matched controls were paired in the original colonies at shipping. To assess reproduction, the following variables were monitored for 110 days for all 96 pairs: number of pairs producing litters, time from pairing to birth, interlitter interval, litter size at birth, and litter size at weaning. Generally, shipping suppressed litter production and delayed its timing, but had less effect on litter size. Overall, 32 of 48 control pairs (67%) produced 69 litters compared with 37 litters from 21 of 48 pairs (44%) after shipping. Pairing-to-first-litter intervals were approximately two oestrous cycles shorter in control animals (39 vs 53 days). Averaged over all litters, litter size was higher in control pairs (4.4 vs 4.0). With respect to genotype, control agouti deer mice were less productive than nonagouti animals, but they reproduced better than nonagoutis after shipping. In control animals, colourmorphs did not differ with respect to litter production or timing, but agouti pairs had smaller litters (first litter: A: 3.1, a: 4.2) and this difference increased at successive litters (third litter A: 3.9, a: 6.0). After shipping, agouti animals produced more litters (A: 22, a: 15), and did so earlier (pairing to birth: A: 47 days, a: 60 days), as well as more frequently (interlitter interval: A: 32 days, a: 51 days). Litter size was also more similar between genotypes after shipping (A: 4.0, a: 4.1). Overall, control agouti animals produced 37% fewer offspring than nonagouti pairs (A: 116 neonates, a: 185 neonates), but after shipping agouti deer mice produced 43% more offspring than nonagouti animals (A: 87 neonates, a: 61 neonates). In sum, transport stress suppressed reproduction for several weeks after shipping and this suppression was exacerbated in nonagouti deer mice.


1977 ◽  
Vol 55 (5) ◽  
pp. 862-871 ◽  
Author(s):  
Daphne J. Fairbairn

Female deer mice (Peromyscus maniculatus) near Vancouver, British Columbia, were found to have a bimodal pattern of breeding. This paper compares the success of females that attempted to breed in the early peak of breeding with that of females that did not breed until the later breeding peak. While the average success was about the same for the two tactics, early breeding had a much higher variance. It is suggested that this difference in variances would result in eventual elimination of the early-breeding phenotype, unless it were favored by other factors. Differences in the selection pressures on males and females, and the relatively frequent occurrence of years of good reproductive success for early-breeding females, may contribute to the maintenance of this phenotype in the population. A hypothesis is presented to explain both the bimodality of the breeding pattern, and the dominance of the second breeding peak.


1989 ◽  
Vol 67 (4) ◽  
pp. 789-794 ◽  
Author(s):  
M. D. Pulsifer ◽  
T. B. Herman

Locomotor, climbing, and nesting behaviors of wild-caught and captive-born deer mice (Peromyscus maniculatus Wagner) from mainland Nova Scotia and from an isolated predator- and competitor-free island were compared in a laboratory observation room. Locomotor activity did not differ consistently between populations, but wall-seeking was significantly greater in mainland mice. When exposed to an artificial tree, insular mice made more climbs than mainland mice, but mainland mice climbed for longer periods. Climbing behavior differed little between males and females in any group. In a choice experiment, mainland mice selected elevated nest sites significantly more often than ground-level nest sites, while insular mice exhibited no preference.


1989 ◽  
Vol 264 (10) ◽  
pp. 5593-5597
Author(s):  
C Norsten ◽  
T Cronholm ◽  
G Ekström ◽  
J A Handler ◽  
R G Thurman ◽  
...  

2006 ◽  
Vol 39 (2) ◽  
pp. 287-300 ◽  
Author(s):  
MHAIRI A. GIBSON ◽  
RUTH MACE

Summary.This study examines the reproductive success of men and women in rural Ethiopia as a function of their marital status, specifically by comparing polygamously and monogamously married individuals. In line with predictions from evolutionary theory, polygamy is beneficial to male reproductive success (i.e. producing larger numbers of surviving offspring). The success of polygamously married females depends on wife rank: the first wives of polygamous husbands do better than monogamously married women and much better than second or third wives. These effects are mirrored in child nutritional status: the children of second and third wives have lower weight for height. Due to potential, largely unmeasurable differences in marriageability (quality) between individuals, it was not possible to support a model of either resource-holding polygyny combined with female choice or female coercion into unwanted marriages. First wives of polygamously married men marry at a younger age and attract a higher brideprice, suggesting that both the males and females in the marriage are likely to be of higher quality (due to wealth, family status or some other factor such as beauty). Unions that end up monogamous are likely to be between slightly lower quality individuals; and second and third wives, who marry at the oldest ages and attract the lowest brideprice, may be ‘making the best of a bad job’. The relatively long gap between first and second marriages may mean that first wives of highly marriageable males can enjoy considerable reproductive success before their husbands marry again.


Virology ◽  
1994 ◽  
Vol 204 (2) ◽  
pp. 563-568 ◽  
Author(s):  
Vivek R. Nerurkar ◽  
Jin-Won Song ◽  
Ki-Joon Song ◽  
James W. Nagle ◽  
Brian Hjelle ◽  
...  

2007 ◽  
Vol 1 (4) ◽  
pp. 396-401
Author(s):  
Cristiane Garcia da Costa Armentano ◽  
Julieta Quayle

Abstract The three words-three shapes test is a brief bedside technique for assessment of learning and memory using verbal and non-verbal material. To the best of our knowledge, performance of Brazilian elderly on this test has not yet been reported. Objective: To evaluate the performance of normal Brazilian elderly on the three words-three shapes test. Method: A total of 50 adult patients, 25 males and 25 females, with age ranging from 55 to 81 years (66.0±7.10 years), 1 to 8 years of schooling, different economic conditions and living in the São José do Rio Preto municipality, State of São Paulo, were evaluated. Results: There was no statistically significant difference between performance of males and females. Performance on incidental recall was significantly lower than in delayed recall. The performance in the learning phase improved following at least two further presentations of the stimuli. Approximately 50% of the participants did not remember the six stimuli and had to proceed to the recognition stage. The performance in the recognition stage was significantly better than during spontaneous recall. Patients with low educational level (less years of schooling) had poorer performance on the recall of shapes and on the total score of the test. Conclusions: The three words-three shapes test is rapid, efficient and straightforward to apply in the elderly, but low educational level was associated with poorer performance on this test. Normal elderly individuals had greater difficulty in the encoding process and in searching for stored information.


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