of their male offspring, Dušan, was tagged with solar-battery satellite tracker. The technology helped management of the growth of the griffon vultures population in the Uvac Special Nature Reserve. It is introduced here for the same purpose and survey of the Belgrade's surrounding nesting areas of white-tailed eagles, like the wetlands of Beljarica or Reva. Mammals On the 9 October 2008 a species of the pygmy bat, soprano pipistrelle, was discovered on the island. It is a rare mammal, having a wingspan of and weight of only . Naturalists suspected that soprano pipistrelle lives in Serbia, in the Obedska bara region, but this was the first time that the bat was actually seen and caught. There are numerous colonies of various bat species on the island. In October 2008, 21 species of mammals were recorded on the island. They included, in Belgrade rarely seen, otters, nutrias, weasels and European pine martens, but also a roe deer. There is a colony of wild boars on the Great War Island. The population originated from the marshy area of Pančevački Rit and they reached the island swimming to it during one of the previous floods. As of 2019, it was estimated to have over 35 individual animals. Rarely, they swim across the arm of the Danube which separates the island from the urban mainland, and can be seen in Zemun or Novi Beograd. Popular case was from 2014 when a wild boar was discovered in the garage of the Energoprojekt holding company. In June 2019 due to the rise of the water level which flooded the entire island, wild boars scattered all over Belgrade, making media sensation. Numerous videos and photos of boars swimming across the rivers were posted. A small herd of wild boars was seen in New Belgrade's Block 30. Animals, including disoriented solitary piglets which is highly unusual behavior, were seen in Block 8 and in the neighborhoods of Ušće and Zemunski Kej. Wild boars have even been spotted in Belgrade's downtown: in Belgrade Fortress and Obilićev Venac, where one animal fell to its death from the multistorey car park. Though hunting organizations stated that there is no danger as wild boars avoid people, Ministry of Agriculture issued a warning, stating that people should abstain from night walks in the forested area across the island. Fluctuating number of wild boars grew again by 2020 and they began to completely devastate