Population monitoring

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!

Griffon vulture monitoring

Griffon vulture monitoring results for the year 2017
During 2017, Priroda Public Institution, in collaboration with the BIOM Association, recounted nesting griffon vulture pairs in the bird reserves and on the island of Plavnik. The first visit was carried out in March, and the second one in June. There were a total of 108 nesting pairs with 76 young birds ready to fly, which means that the incubation efficiency was 70.37%. Within the NATURA 2000 ‘HR1000033 Kvarner Islands’ area, the Ordinance on the conservation objectives and basic measures for the conservation of birds in the ecological network area (Narodne novine Official Gazette, No. 15/2014) determines that between 110 and 130 nesting pairs are needed in order to preserve the species. The obtained data suggest that the number of nesting pairs is at the lower limit of the determined range for the conservation of the species, which means that it is important to continue monitoring in order to follow the population trend.

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