Paul dolphins have learned to identify scars

New Zealand zoologists have developed a technique that allows a dolphin to determine the sex photos. The only essential instrument is a digital camera fitted with a simple device of laser ukazok. The work of researchers published in the journal Marine Mammal Science. Briefly the main findings of the leading portal Nature News.

Males and females dolphins have no clear morphological (external) differences. Typically, half of these animals to determine behavioral characteristics (for example, females spend more time with the young) or for primary sex (when jumping dolphin scientists managed to see his genitals).

The authors of this work as a diagnostic trait chosen dorsal fin. It is visible in photographs, which zoologists are doing in the routine monitoring of populations of dolphins. By the usual digital camera, researchers put the two laser pointer, "speck" which allows measured in ten centimeters. With the help of "new" device zoologists can accurately determine the dorsal.

Scientists photographed dolphin-afalin of the population, which they knew. After reviewing the images, the researchers determined that at plavnikah males more scars than plavnikah females. On average, for males plavnikah scars were about 15 per cent, while the plavnikah females - 3.9 per cent. Scientists attribute the differences more aggressive males, who often come to loggerheads.

Using statistical data on the amount of fin and the space occupied by scars, the scientists were able to predict the sex of 93 per cent of dolphins from the group, which had 43 animals. The authors of the method argue that the method can be easily adapted to other types of dolphins.