RESUMEN
Sexually naive male and female montane voles (Microtus montanus) were tested in a two-choice odor preference situation. Females, but not males, spent more time investigating bedding soiled by a conspecific of the other sex than clean, unsoiled bedding. Both naive females and males spent more time near male-soiled rather than female-soiled bedding. Males with extensive monogamous sexual experience exhibited a preference for female-soiled bedding when the comparison stimulus was clean bedding but no preference when the comparison was with male-soiled bedding.
Asunto(s)
Arvicolinae/fisiología , Atractivos Sexuales/fisiología , Conducta Sexual Animal/fisiología , Olfato/fisiología , Animales , Conducta de Elección/fisiología , Femenino , Masculino , Medio SocialRESUMEN
Place learning was assessed in three species of voles (Microtus ochrogaster, M. montanus, and M. pennsylvanicus) with the Morris swim task. The performance of all 3 species and both sexes improved with training on the hidden-platform version of the Morris swim task, which indicates that all groups were able to learn to locate a spatial goal without local cues. Contrary to expectations, no evidence for a sex difference in spatial ability emerged in any of the species. These findings do not provide support for current hypotheses that emphasize a positive correlation between home-range size and laboratory measures of spatial ability.
Asunto(s)
Arvicolinae , Aprendizaje , Conducta Espacial , Animales , Conducta Animal , Encéfalo/anatomía & histología , Encéfalo/fisiología , Factores Sexuales , Análisis y Desempeño de TareasRESUMEN
This study was designed to determine testes masses, total number of spermatozoa ejaculated per copulatory episode, and the pattern of sperm numbers in successive ejaculates in prairie voles (Microtus ochrogaster), montane voles (M. montanus), pine voles (M. pinetorum), and meadow voles (M. pennsylvanicus). Prairie voles displayed mean totals of 2.7 ejaculations and 30.5 X 10(6) spermatozoa before reaching a satiety criterion; montane voles 3.4 ejaculations and 19.0 X 10(6) spermatozoa, pine voles 2.4 ejaculations and 3.3 X 10(6) spermatozoa, and meadow voles 2.5 ejaculations and 25.5 X 10(6) spermatozoa. In all species the number of spermatozoa decreased in successive ejaculates. Significant species differences were noted for the total number of spermatozoa ejaculated and number of spermatozoa ejaculated in each of the first 3 ejaculates. Species differences also were noted for testes mass, with meadow voles having the largest testes and pine voles having the smallest. These data can be compared to similar data on laboratory rats and deer mice and related to recent theory regarding sperm numbers, testes sizes, and mating systems. In general, the species with large testes appear to ejaculate more spermatozoa. The significance of species differences in testes mass and total sperm numbers remains unclear, but may relate to the occurrence of multiple mating by females during a single receptive period.
Asunto(s)
Arvicolinae/fisiología , Espermatozoides/fisiología , Animales , Arvicolinae/anatomía & histología , Copulación/fisiología , Eyaculación/fisiología , Masculino , Recuento de Espermatozoides , Testículo/anatomía & histologíaRESUMEN
The temporal patterning of ultrasonic vocalizations (USVs) during copulation was recorded for male-female pairs of Djungarian hamsters (Phodopus campbelli), prairie voles (Microtus ochrogaster), and montane voles (Microtus montanus). Each species appears to utilize a single major frequency band for USVs, centered around 31 kHz for the vole species and 71 kHz for hamsters. Djungarian hamsters exhibited low rates of USVs prior to introduction of the female and following ejaculation, but a high USV rate during periods of copulatory activity. Both vole species called at high rates during all stages of the copulatory sequence, although calling rates decreased following ejaculation. Anesthetization trials, where one pair member was awake and the other anesthesized, suggest that it is the male of each species that produces most USVs. The results were compared with six other muroid species for which data on the temporal patterning of USVs during copulation are available. These data extend our knowledge of the patterning of USVs during copulatory behavior and suggest the need for additional comparative investigations.
Asunto(s)
Copulación , Espectrografía del Sonido , Ultrasonido , Vocalización Animal , Animales , Arvicolinae , Cricetinae , Femenino , Masculino , Especificidad de la EspecieRESUMEN
This study was designed to delineate the course of sexual satiation in prairie voles (Microtus ochrogaster). Fourteen male-female pairs were allowed to copulate freely for 24 hr under continuous observation. Copulations occurred predominantly during the first few hours and decreased in frequency thereafter. The mean number of ejaculations per pair was 5.6 (range, 2-9). Two thirds of the ejaculations occurred during the first 3 hr, and over 90% took place within the first 7 hr after the first intromission. No ejaculations were observed during the last 8 hr. These results suggest that male capacity to deliver ejaculations to a female is limited and that direct observations reveal a more limited capacity than observations made with time-lapse videotape.
Asunto(s)
Saciedad , Respuesta de Saciedad , Conducta Sexual Animal , Animales , Arvicolinae , Copulación , Eyaculación , Femenino , MasculinoRESUMEN
Rodents of the genus Microtus provide an excellent focus for the study of the effects of environmental and behavioral influences on reproductive physiology. Despite some early reports, there is little definitive evidence of truly spontaneous ovulation in Microtus. Stimuli from copulation with males appear capable of triggering ovulation in all species: the requisite amount of stimulation for ovulation and a functional luteal phase varies with the species. In addition, however, a certain percentage of the females of some, but not all, species ovulate when placed in proximity to males when copulation is presented. There are few reports of regular cycles of cell types in the vaginal smears of Microtus females; the relative preponderance of cornified, nucleated, and leukocytic cells varies with species and conditions. Behavioral receptivity is not invariably correlated with smear type. The complexity of environment-behavior relationships in different species suggests the need for a more comprehensive classification schema for systems of female reproductive physiology and a study of their adaptive significance.