It rains male buffaloes when it rains
May 2nd, 2010 - 1:31 pm ICT by ANIWashington, May 2 (ANI): Rainfall is linked to skewed sex ratios, according to a study on buffaloes.
Scientists noted that an increased proportion of male African buffalo are born during the rainy season.
Researchers collected data from more than 200 calves and 3000 foetuses, finding that rain likely exerts this effect by interaction with so-called sex ratio (SR) genes, which cause differences in number, quality or function of X- and Y-bearing sperm.
Pim van Hooft, from Wageningen University, The Netherlands, worked with a team of researchers to study animals in the Kruger National Park, South Africa.
He said: “Here we show temporal correlations between information carried on the male Y chromosome and foetal sex ratios in the buffalo population, suggesting the presence of SR genes. Sex ratios were male-biased during wet periods and female-biased during dry periods, both seasonally and annually”.
The researchers studied data collected between 1978 and 1998 to look at the associations between rainfall, birth rates/ratios and genetic information.
They found ejaculate volume, sperm motility and proportion of normal-shaped sperm decrease significantly during the dry season.
This decline in quality is likely due to decreasing availability and quality of food resources.
Pim van Hooft said: “These observations may point towards a general mechanism in mammals whereby semen-quality related sex-ratio variation is driven by SR genes”.
The study has appeared in the open access journal BMC Evolutionary Biology. (ANI)
- Rainfall associated with skewed sex ratios - Apr 23, 2010
- Promiscuous females can help save the human race - Feb 26, 2010
- Having too many sisters 'makes a man less sexy' - Oct 22, 2010
- Polygamous mice 'have more fertile offspring' - Feb 05, 2011
- Production of sperm may lower immunity - Jan 31, 2012
- Students to track sex determination centres - Aug 17, 2011
- Haryana raises monthly aid to daughters-only parents - Jul 07, 2011
- Ring finger length linked to male libido - Sep 06, 2011
- 'Sex selection now spreads to Hayana's rural poor too' - Sep 02, 2011
- Brain gene responsible for making a female develop as a male identified - Dec 23, 2010
- Human sperm gene is 600 million years old - Jul 16, 2010
- Female butterflies chase males when it's cool - Jan 07, 2011
- Scientists discover male infertility gene - Oct 01, 2010
- Female crickets fall for louder songs sung by younger males - Jan 15, 2011
- Genetic analysis challenges human-chimp interbreeding - Aug 29, 2009
Tags: african buffalo, birth rates, bmc evolutionary biology, buffalo population, buffaloes, decline in quality, dry periods, foetal, foetuses, food resources, genetic information, kruger national park, kruger national park south africa, motility, rainy season, sex ratio, sex ratios, wageningen university, wet periods, y chromosome