Size does matter when it comes to being a daddy!

In a study into the mating habits of mammals, scientists have discovered that size really does matter. For when it comes to getting the female of the species pregnant, researchers claim that well endowed males are far more successful.

While they did not necessarily attract mates more easily, they were more likely to father offspring at the first attempt. The authors of the study - which looked at the love lives of 122 different animals think that the increased success rate may be because the sperm can be deposited closer to the egg.

Scientists studied a huge range of species and found a massive variation in the size of their man-hoods.

Those with the largest had the best chance of inseminating a female. The authors of the study said that the difference illustrated evolution at work. Mammals living in artic regions like the walrus are better endowed because they need to be more successful at mating.

The hostile Arctic landscape supports few individuals, so walruses tend not to come into contact with each other very frequently, meaning that sexual encounters are few and far between so males with a greater chance of inseminating their sexual partners might win the evolutionary race. Walruses had therefore evolved to make them more likely to be successful in a single sexual encounter. Less well- endowed elephant seals on the other hand live in a warmer environment where populations are denser.

They encounter female seals more often, so making one pregnant-at the first attempt is not such a priority for the survival of their species. The research for the Delta Waterfowl Foundation in Portage La Prairie, Canada, said that the findings applied to all species of mammals.

Scientists generally believe that a man's height and body shape make the most difference in his hunt for a mate.