caa a22 4500 465782302 CHVBK 20180323111958.0 cr unu---uuuuu 170327e19900201xx s 000 0 eng 10.1007/BF00171579 doi (NATIONALLICENCE)springer-10.1007/BF00171579 Litter sex ratios in the golden hamster vary with time of mating and litter size and are not binomially distributed [Elektronische Daten] [U. Huck, Jon Seger, Robert Lisk] Summary: Pregnancy rates, litter sizes, and litter sex ratios vary strongly with the time in the estrous cycle at which female golden hamsters (Mesocricetus auratus) are mated. Early matings tend to produce relatively high pregnancy rates, large litters, and female-biased sex ratios, while late matings tend to produce low pregnancy rates, small litters, and male-biased sex ratios. Time of mating and litter size are therefore correlated, but each appears to have an independent effect on litter sex ratio: time of mating and sex ratio are positively correlated, holding litter size constant, while litter size and sex ratio are negatively correlated, holding time of mating constant. At each litter size greater than two, the variance of litter sex ratios is less than the binomial variance expected on the hypotheses of independent sampling with a constant probability of producing a male. The main features of the distribution of litter sex ratios can be generated from a causal model in which different probabilities of producing a male apply to "early” and "late” conceptions within each litter. The relationship between litter size and mean litter sex ratio is potentially consistent with several different models for the evolution of adaptive sex-ratio variation. Springer-Verlag, 1990 Huck U. Biology Program, Sangamon State University, 62708, Springfield, IL, USA aut Seger Jon Department of Biology, University of Utah, 84112, Salt Lake City, UT, USA aut Lisk Robert Department of Biology, Princeton University, 08544, Princeton, NJ, USA aut Behavioral Ecology and Sociobiology Springer-Verlag 26/2(1990-02-01), 99-109 0340-5443 26:2<99 1990 26 265 https://doi.org/10.1007/BF00171579 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00171579 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Huck U. Biology Program, Sangamon State University, 62708, Springfield, IL, USA aut NATIONALLICENCE 700 1- Seger Jon Department of Biology, University of Utah, 84112, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Lisk Robert Department of Biology, Princeton University, 08544, Princeton, NJ, USA aut NATIONALLICENCE 773 0- Behavioral Ecology and Sociobiology Springer-Verlag 26/2(1990-02-01), 99-109 0340-5443 26:2<99 1990 26 265 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer