Female brown bears are driven to having many partners - not because of lust but as part of a sophisticated strategy for protecting future offspring. This surprising discovery is the result of a large-scale project by the Austrian Science Fund FWF in which the bear population in Scandinavia was closely observed in the wild. The data, that goes back for over 20 years, is published today and is contributing to a better understanding of this species which is once again becoming native to Europe.
(I-Newswire) - Female brown bears are driven to having many partners - not because of lust but as part of a sophisticated strategy for protecting future offspring. This surprising discovery is the result of a large-scale project by the Austrian Science Fund FWF in which the bear population in Scandinavia was closely observed in the wild. The data, that goes back for over 20 years, is published today and is contributing to a better understanding of this species which is once again becoming native to Europe.
The urge to reproduce has little to do with lust and a lot to do with population biology. Each creature would like to pass on its genetic information to the next generation, and is often prepared to go a long way to gain an advantage. For example, male bears do not stop at killing the offspring of other fathers. A team from the Department for Integrative Biology at the University of Natural Resources and Applied Life Sciences in Vienna has now discovered an elaborate strategy used by female brown bears to counter this danger – numerous copulations with as many partners as possible.
Mean Genes During the mating season from May to July, male brown bears have one overriding aim — to impregnate as many females as possible. A hindrance to this is females that are not yet in estrus because of existing cubs. Male brown bears have developed a simple and brutal way of getting round this problem. The offspring of other male bears are unceremoniously killed, meaning that the mother enters estrus again.
This instinctive course of action has two advantages. Firstly, the cubs that would have passed on the genes of other fathers are eliminated, and secondly the female is ready to mate and can be impregnated with the male’s genes.
The killing of her litter has a big disadvantage for the female - the loss of a generation with her genetic material. The Austrian researchers have now discovered that females in bear populations where these killings of offspring are rife have developed a counterstrategy.
Protection Through Promiscuity As project leader Andreas Zedrosser explained: "Normally a brown bear female only mates with one male. This however means that many other males will not see the cubs as their own and could possibly kill them. Things are different when the brown bear female copulates with a large number of males. They will then believe themselves to be the fathers and leave the litter alone. In fact, 54% of the bear mothers observed during the project actually adopted this strategy."
When the female mates with several males the first partner is by no means always the biological father. On the contrary, the study strongly suggests that female bears are capable of controlling their ovulation and only decide on the sperm of a particular partner after fertilisation. Although it is not yet clear how this is possible, the data shows that two criteria in particular play an important role in the selection of the father - body size and the degree of heterozygosity ( diversity of genetic information ). The latter permits greater genetic diversity in the litter, and therefore improves the odds of survival for the entire population.
These surprising insights into finely balanced reproduction strategies were made possible by extensive observation of European brown bears in Scandinavia. Adult brown bears and females with their young were captured between 1984 and 2003, and fitted with radio transmitters in order to study their behaviour. The data analysed by the FWF project makes an important contribution to the previously under-researched study of the mating behaviour of European brown bears, a species which is also increasingly resettling Austria.
Publication on 2nd November 2005: The dilemma of female mate selection in the brown bear, a species with sexually selected infanticide. Proceedings of the Royal Society – Biological Sciences. doi:10.1098/rspb.2005.3331
Scientific Contact: Mag. Andreas Zedrosser University of Natural Resources and Applied Life Sciences Vienna Institute for Game Biology and Hunting Management Peter Jordan-Strasse 76 A-1190 Vienna, Austria T +47 / 9910 / 2503 E-mail: andreas.zedrosser@umb.no
Austrian Science Fund FWF: Mag. Stefan Bernhardt Weyringergasse 35 A-1040 Vienna, Austria Tel: +43 / 1 / 505 67 40 - 36 E-mail: bernhardt@fwf.ac.at
Copy Editing & Distribution: PR&D – Public Relations for Research & Development Campus Vienna Biocenter 2 A-1030 Vienna, Austria Tel: +43 / 1 / 505 70 44 E-mail: contact@prd.at
Vienna, 2nd November 2005
If you have questions regarding information in this press release contact the company listed below. I-Newswire.com is a press release service and not the author of this press release. The information that is on or available through this site is for informational purposes only and speaks only as of the particular date or dates of that information. As some companies / PR Agencies submit their press releases once per week/month or quarter, make sure check the official company website for accurate release dates as our site displays the I-Newswire.com distribution date only. We do not guarantee the accuracy or completeness of information on or available through this site, and we are not responsible for inaccuracies or omissions in that information or for actions taken in reliance on that information.
Immerse yourself in mystery and magic with two exciting new casual games from Focus Multimedia and Big Fish Games Studios, one of the world’s leading casual game developers. Hidden Expedition Titanic and Azada join Focus’ popular Revival range of super-budget price games and are available in a store near you.
Edraw Max enables students, teachers and business professionals to reliably create and publish kinds of diagrams to represent any ideas. With large pre-drawn libraries and more than 4600 vector symbols, drawing couldn't be easier!
New range of cards launched to make you the cover star.Hallmark Cards in partnership with OK Magazine has launched an exclusive and exciting new range of greeting cards that gives people the chance to give family and friends the A-List treatment.
Many people choose not to pursue an accident claim. The reasons range from knowing the insurance company will settle; to they don't want the legal hassles and expense.
Many individuals and businesses have always purchased their personal computers from a well-known provider to pre-conceived specifications. Increasingly...
The effectiveness of SEO and PPC Services are directly related to the quality and quantity of the performance data that they have to work with. If you are seeking assistance in achieving a higher ranking on search engine results, then we suggest you visit RankYourWebsites.com, specialist in this area. If you have found your attempts at optimization to prove fruitless, the representatives at RankYourWebsites.com will have a solution to increase your traffic.
http://www.vineyardsforsalein.com/ - online island vineyard for sale, vineyard for sale paso, texas vineyard for sale, washington vineyard for sale, tuscany vineyard for sale, vineyard for sale santa, vineyard for sale California
Mark Flanagan, Managing Director of Manchester health and safety, food safety and fire safety consultancy, Shieldyourself, discussed the Scores on the Doors scheme when he made a guest appearance on the BBC’s 5 Live Radio Show recently.
