Season, reproductive

Qualitative and quantitative comparisons of the constituents of the urine of male and female white-tailed deer indicated that the presence and concentration of the urinary compounds depend on the season, reproductive status and social rank of the animals [ 132,133]. Of the 63 and 55 compounds characterized in female and male urine, respectively, 27 were common to both sexes, 36... 

Legan SJ, Karsch FJ, Foster DL (1977) The endocrine control of seasonal reproductive function in the ewe a marked change in response to the negative feedback action of estradiol on luteinizing hormone secretion. Endocrinology 707 818-824. 

Crim, L.W. and D.R. Idler. Plasma gonadotrophin, estradiol, and vitellogenin and gonad phosvitin levels in relation to the seasonal reproductive cycles of female brown trout. Ann. Biol. Anim. Biochem. Biophys. 18 ... 

Lye, C.M., C.L.J. Frid and M.E. Gill. Seasonal reproductive health of flounder Platichthys flesus exposed to sewage effluent. Mar. Ecol. Prog. Ser. 170 249-260, 1998. 

Kuhn, H. J., 1976, Antoibitaldriise und TrSnennasengang vonNeotraguspygmaeus, Z. Sdugetier. 41 369-380. Lillie, R. D., 1961, Histopathogenic Technic and Practical Histochemistry. Blakiston Co., New York, pp. 120. Lincoln, G. A., 1971, The seasonal reproductive changes in the red deer stag (Cervus elaphus), J. Zool, Bond. 163 105-123. 

Gilmore, D.P. 1969. Seasonal reproductive periodicity in the male Australian Brush-tailed possum Trichosurus vulpecula). J. Zool, Lond., 157, 75—98. 

Zucker, I., Johnston, P. G. Frost. D. 1980. Comparative, physiological and biochronometric analyses of rodent seasonal reproductive cycles. Prog. Reprod. Biol. 5, 102—103. 

Potential impacts of contaminants on habitat are reductions in cover and quality. The loss of preferred habitat may leave animals more susceptible to predation and disease. Loss of reproductive habitat may result in fewer animals reproducing in a given season or exposing the young to increased predation. For some animal populations, then, habitat changes may lead to decreased reproduction, increased mortality, and increased emigration. 

Barber, D.S., McNally, A.J., Denslow, N.D., and Garcia-Reyero, N. et al. (2007). Exposure to p,p -YyOE or dieldrin during the reproductive season alters hepatic CYP expression in largemouth bass (Micropterus salmoides). Aquatic Toxicology 81, 27-35. 

The determinants of F. have been subject to experimentation mostly in field and captive studies of ungulates. These support the expected association between the frequency and occurrence of Flehmen and the seasonality of reproduction. The elicitation of F. can also depend upon the social context presentation of urine or other stimuli alone may not produce consistent displays. When conspecific urine was tested out of context (i.e. no female present) in male Black-tailed deer, there was no discrimination between urine from individual adult males or between urine from estrous/non-estrous females (Altieri, 1980). Correlation of male endocrine status in reindeer (Rangifer tarandus) showed that the elevation of testosterone during rut and the duration of F. elicited by female urine was coincident F. bouts during rat were twice as long following exposure to adult female urine as to that of immature females (Mossing and Damber, 1981). 

Season of collection (Fowler and Oregioni 1976 Sanders etal. 1991) and latitude (Anderlini 1974) also influenced silver accumulations. Seasonal variations in silver concentrations of Baltic clams (Macoma balthica) were associated with seasonal variations in soft tissue weight and frequently reflected the silver content in the sediments (Cain and Luoma 1990). Oysters from the Gulf of Mexico vary considerably in whole-body concentrations of silver and other trace metals. Variables that modify silver concentrations in oyster tissues include the age, size, sex, reproductive stage, general health, and metabolism of the animal water temperature, salinity, dissolved oxygen,... 

Fed diet with 15 mg Se/kg ration as selenomethionine for 21 weeks during winter, ending with onset of reproductive season Ducklings fed diets for 4 weeks containing 15 or 60 mg Se/kg ration as selenomethionine, with and without 1000 mg boron/kg ration Females that had just initiated egg laying were fed diet containing 20 mg Se/kg ration as selenomethionine for 20 days, then an untreated diet for 20 days... 

Pollen allelopathy can find utilization in field cultivations that could contain pollen of allelopathic crops or weeds. Pollen allelopathy could be an effective method for annual weed control that reproduce, at least in part, via wind pollination and flower concurrently with the allelopathic species. The effects of allelopathy should result in the loss of genetic variation and so in reduction of reproductive ability, but some plants are probably able to detoxify the pollen allelochemicals (Murphy and Aarssen 1995a, b). Murphy and Aarssen (1989) suggested possible delaying of weed flowering at later, less favorable times of the season or diurnal period, so decrease in weed pressure. However, infestation by perennial weeds can worsen due to compensation of pollen allelopathy through increase in the formation of rhizomes. 

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