Around a hundred pairs of griffon vultures nest on the Kvarner islands, and Priroda Public Institution, in cooperation with the BIOM Association, visits the colonies several times a year in order to find out the number of nesting pairs and the success of nesting for the current year. Colonies are visited by boat and the number of active nests is counted, as well as the number of fledglings.
Long-term population monitoring is important in order to obtain information about trends, i.e. to see if the population is stable, increasing or decreasing. A downward trend in numbers has been noticed in nesting pairs over the last few years. The greatest challenge seems to be the reduced availability of food (carcasses) because of a decrease in traditional sheep and cattle breeding, as well as a lower livestock mortality rate due to the improved quality of veterinary care. The fact that at the beginning of the 20th century there were around 60,000 sheep on the island of Cres while today there are only 15,000 indicates that there has been a significant reduction in the source of food in the wild!