Large gulls in man-made landscapes of the Western Murman (Kola Peninsula). - Yu.I. Goryaev, A.A. Goryaeva, I.P. Tatarinkova. - Berkut. 20 (1-2). 2011. - P. 90-110.
Ecological peculiarities of Herring and Great Black-backed Gulls living on the coast and islands in the area of the Kola Bay and actively using man-made landscape as feeding habitat were investigated for the first time in 2008–2011 during the period April – August. In conditions of shortage of the fish food in the sea, here is formed a large group of seagulls (Herring Gull makes the overwhelming majority). It constitutes a substantial proportion of the modern population of gulls of Murman (presumably 3000–4000 breeding pairs, 14000–20000 mature and immature individuals). On average for 4 years, the number of gulls of both species, periodically visiting the Murmansk rubbish dump during the summer season, defined by method of labeling with the re-registration, made up 16450 ± 1204 individuals. From 2008 to 2011, аccording to these records, the number of birds increased in about 3.2 times – from 8500 (± 904) to 27600 (± 1864) individuals. Herring and Great Black-backed Gulls nested in mixed colonies (ranging from 0.2 to 11 ha.) in most of the islands in the study area (a total of 42 islands ranging from 0.2 to 130 ha.). The population density made up respectively 37–100 and 1–2 pairs/ha. of the colony. The average clutch size of Herring Gulls on a permanent test area on the Shalim island was in 2009 2.88 ± 0.07, in 2010 – 2.90 ± 0.07, in 2011 – 2.80 ± 0.04 eggs. The difference in mass of the largest and smallest eggs for 3-egg clutches was on average 5.8 ± 0.44 g (n = 150), the average weight of eggs made up 93.0 ± 0.49 g (n = 220). Average daily weight gain of chicks of Herring Gull during 5–33 days was about 25 g (y = 24.85x +31251). Survival of chicks in 2009 and 2011 at 31st day was about 0.55 per pair (taking into account the possible errors – up to 1 chick per pair). The average body weight of mature females and males of Herring Gull (n = 46 and 45) was in July respectively 982 ± 10,5 g and 1211 ± 13,4. The basis of the diet of adult birds and their chicks were the waste. [Russian].
Key words: Larus argentatus, Larus marinus, ecology, abundance, breeding, feeding.
Address: Yu.I. Goryaev, Murmansk Institute of Marine Biology, Vladimirskaya str. 17, 183010, Murmansk, Russia; e-mail: ygoryaev@yandex.ru.