Acrocephalus 22 (109): 227 – 228, 2002
227
Nidifications by Yellow-legged Gulls Larus cachinnans
on buildings are not new in Europe. Nesting on
buildings was first documented on the Bulgarian
Black Sea shores in 1894 (Nankinov 1992) and is now
diffused in the Mediterranean basin (Barcelona,
Rome, Genoa, Istanbul); in northern Europe the same
behaviour is observed in Herring Gulls Larus
argentatus with urban colonies in France, Germany
and above all England (Cramp 1971, Monaghan et al.
1979, Vincent 1988). 
In Trieste, the nesting population has rapidly
increased since the first pair was found in 1987
(Benussi et al. 1993): 68 pairs were counted in 1992,
155 in 1996, and 299 in 2000; breeding pairs use now
every kind of rooftop (and even cranes, flower-pots
and meadows) and are getting increasingly used to the
presence of man. Two nests of the Yellow-legged Gull
Larus cachinnans michahellis were located in the Karst,
not far from Trieste, during summer 1999. One was
found on June 27th on a tiled roof in Sesana (Se`ana -
Slovenia) where a 40 days old pullus was observed
together with adults. A second nest, with three 45
days old pulli ready to fly, were located on July 14
th
in
Villa Opicina (Trieste), on a horizontal roof covered
with pebbles and grass. Both in Se`ana and Villa
Opicina other adults as well as 1st and 2nd summer
individuals were seen in flight. During 2000, the two
nesting pairs were watched on a regular basis during
the entire breeding season, and data on their breeding
success, presence of other gulls and food availability
were collected. Both pairs nested on the same site
using the very same cup; in Se`ana there was one
chick that did not fledge (possibly due to predation),
in Villa Opicina two chicks were hatched and
successfully flew away in the first week of July.
Small flocks of adults and immatures were always
present in both places (5.5 on average in Opicina, 2.6
in Se`ana). Main food source appeared to be a dump
in Slovene territory, located 2.5 km from Se`ana, and
6 km from Villa Opicina, where flocks of 20-30
Yellow-legged Gulls (and up to 120), probably from
Trieste, were repeatedly observed; yet again, food was
most likely found in garbage cans, the same as in
Trieste (Benussi & Bembich 1998, Bembich 1998), or
was brought to the chicks from the city. 
The two nidifications confirm, in the Yellow-
legged Gull breeding site choice, the importance of
close food sources (Perco et al. 1986), whereas land
typology (in this case woods, small meadows and
cultivated patches) seems not to be important if a safe
place for the nest can be found; they also correspond
to the spreading of the urban colony in Trieste, where
many isolated pairs have been located during the last
few years, for example in southern suburban areas.
Summary 
The first two nests of the Yellow-legged Gull Larus
cachinnans michahellis were located in the Karst
during the summer of 1999. Data about their
presence, breeding success and food availability were
collected during 2000. The two breeding pairs
probably came from Trieste, where a large colony is
present. In the urban area, L. c. michahellis is
increasing in numbers (68 pairs in 1992, 155 in 1996,
299 in 2000) and shows high breeding success, i.e.
between 50% and 74%. The main food sources are
refuse found by garbage cans, fish offal and left-overs. 
Povzetek
Poleti 1999 sta bila na Krasu odkriti prvi dve gnezdi
rumenonogega galeba Larus cachinnans michahellis,
leta 2000 pa je avtor ~lanka zbiral podatke o galebovi
gnezditveni uspe{nosti in razpolo`ljivosti hrane.
Gnezde~a para po vsej verjetnosti izvirata iz Trsta, kjer
gnezdi ve~ja kolonija teh galebov. V urbanih obmo~jih
se gostota rumenonogega galeba vztrajno pove~uje (68
parov leta 1992, 155 parov leta 1996 in 299 parov leta
200), hkrati pa se pove~uje tudi njegova gnezditvena
uspe{nost, t.j. med 50% in 74%. Galebov glavni vir
hrane so razli~ni organski odpadki ob smetnjakih in
ribja mrhovina.
First breeding of the Yellow-legged Gull Larus cachinnans michahellis
in the Karst
Prvo gnezdenje rumenonogega galeba Larus cachinnans michahellis na Krasu
Luca Bembich
Via Pinguente 6, I-34146 Trieste, Italy, e-mail: lucabembich@hotmail.com
Kratki ~lanki / Short articles
228
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Prispelo / Arrived: 6.6.2002
Sprejeto / Accepted: 1.3.2002