EUROPA − Birds, Yellow-legged gull

When we mention gulls, the image of Jonathan Livingston Seagull crops up in our minds, reminding us of the symbolism of achieving knowledge in free flight, which was outlined by R. Bach (1970). Croatia is a maritime country and one of the most beautiful things connecting its sea to the sky is the yellow-legged gull, Larus michahellis. There are more than 50 gull species around the world and, in Croatia, the yellow-legged gull nests on distant and uninhabited isles and islets in the Adriatic. It used to be considered aIzdavaË: HP−Hrvatska poπta d.d., JuriπiÊeva 13, ZAGREB, HRVATSKA Herausgeber: Kroatische Post, JuriπiÊeva 13, ZAGREB, KROATIEN Published by Croatian Post Inc., JuriπiÊeva 13, ZAGREB, CROATIA subspecies of L. cachinnans michahellis, but nowadays it is categorized as a separate species. The yellow-legged gull is characterized by its yellow legs and grey back and wings with darker tips on the primary flight feathers. It has webbed feet. Its neck and abdomen are white, while its bill is yellow with a bright red spot on the lower jaw. It is between 55 and 67 cm long and its wingspan varies between 130 and 150 cm. The two genders look similar. The yellow-legged gull lays eggs on the ground with sparse vegetation but nesting on rooftops has also been recorded (Rovinj, Istria). It nests in colonies. It is ready to nest at between three and fve years of age. It produces only one brood a year. In April, May or June, the female lays 2 or 3 eggs. Both the male and the female incubate the eggs for 28 to 30 days and both feed the young. The chicks stay in the nest for another 35 or 40 days. The yellow-legged gull can live for 10 years or longer. Its diet consists of fsh, crabs and shellfsh, but it also relies on other food of animal or plant origin. In order to feed, it enters inhabited areas and travels deeper into the Croatian mainland to visit landfll sites where it has also been known to gather in larger numbers. Its diet can also include carrion. The yellow-legged gull population in Croatia has been estimated to include between 40,000 and 60,000 nesting pairs. This species is not endangered, but stable; however it is protected by law (The Rules on the Protection of Certain Bird Species (Aves)), so locals are not allowed to take its eggs. If its nest is robbed, the yellow-legged gull makes up for the loss by producing another brood in the same season. The yellow-legged gull is a resident bird and it spends the entire year near its nesting site. However, young gulls can take part in dispersive migrations outside the Adriatic area, moving inland to visit fresh waters, and some have even been known to migrate to the coasts of northern Europe, from where they returned to the Adriatic. These migrations by the local yellow-legged gull populations have been proven by ringing and bio-marker analysis, which was performed in Croatia for the frst time (1988). Jasmina MuæiniÊ, PhD, retired Senior Research Fellow