Mew Gull Larus canus breeding in a residential area of Malmö, Sweden

72 Citation: Chávez Villavicencio C & Márquez Bahamonde M. 2019. Mew Gull Larus canus breeding in a residential area of Malmö, Sweden. Ornis Svecica 29: 72–75. https://doi.org/10.34080/os.v29.19924. Copyright: © 2019 the author(s). This is an open access article distributed under the CC BY 4.0 license, which allows unrestricted use and redistribution, provided that the original author(s) and source are credited. S HOR T COMMUNIC AT ION


Introduction
The Mew Gull Larus canus is an abundant species that inhabits North America and Eurasia (Burger et al. 1996). It traditionally nests both along the coast and inland, either in colonies or in solitary pairs (Svensson et al. 1999, Skórka et al. 2006. Nests along the coast are located on rocky cliffs with vegetation, sandy beaches and pebbles, dunes, stacked debris from floods or tides, on islands, and on rocky islets (Burger et al. 1996, Snow & Perrins 1998. Inland, the species nests on small islands in freshwater and saline lakes, swamps, stony beaches in streams, rivers, and man-made structures, such as industrial reservoirs, where it uses gravel extraction sites and sedimentation pools (Burger et al. 1996, Snow & Perrins 1998, Svensson et al. 1999 was approximately 10 to 12 m and the surface of the roofs reached 0.5 ha. Around and between the buildings were gardens with lawns, bushy vegetation and trees, as well as parking areas. There was constant movement of cars in the area and the noise of the vehicles was noticeable from any point. The closest distance to the sea is 4.8 km to the northwest.
The observations were made in July 2019. The first encounter with breeding Mew Gulls was casual, while the second was made after searching the surrounding area. Next, a nesting couple was chosen and their behaviour was observed, as well as their interaction with the people who inhabit the housing complex. This was carried out for four days. Finally, a person who lives in one of the buildings, and serves as chair of the tenant owners' association of the housing complex, was interviewed. He was asked about the presence of Mew Gulls in the areas, such as the approximate date of the beginning of the reproductive activity in these buildings and a preliminary perception of this species and their activity.

Results
Two breeding attempts were recorded on the roof of two of the eight buildings in the study area ( Figure  1). Nest 1 was located between the rainwater collector channel and the roof of a balcony and contained three chicks ( Figure 2). One of the parents fed the chicks at least twice between 10:00 and 13:00 and twice between 16:00 and 20:00. On one occasion during the day, one of the parents behaved aggressively towards a person who was walking at a distance of 28 m along the opposite sidewalk. The bird followed the person for 40 m fluttering over their head with characteristic shouts, without touching them, presumably to protect its territory. Nest 2 held two young in the stage of fledgling. One of them we found on the ground, calling while hiding among the vegetation.
The interview with the chairman of the tenant owners' association revealed that Mew Gulls have nested on these buildings at least since 2012. Many residents consider the species harmful to them because the roofs of the houses they nest on get dirty with faeces, leaving a bad smell. The gulls are also considered noisy and occasionally interact with people who rest in the courtyard, by stealing their food or showing aggressive et al. 2006). Mew Gulls can also be found nesting in nest-boxes made for other species (Burger et al. 1996).
It is known that both this and other gull species frequently breed in urban areas and in man-made structures. While there are systematic and quantitative data from the UK and Ireland (Raven & Coulson 1997, Mitchell et al. 2004, Rock 2005, we have only found urban breeding mentioned very briefly for Sweden (Svensson et al. 1999, Rock 2005. We here report observations of breeding Mew Gulls in an urban area of Malmö in southern Sweden, including information about how human residents in the area perceive the birds. Given that humans often perceive urban gulls as a problem (Rock 2005), with our note we hope to stimulate the scientific community to carry out more thorough studies on the abundance and behaviour of seagulls nesting in urban areas in Sweden.

Material and methods
We found Mew Gull nests in a housing complex of Västra Söderkulla, Malmö (55° 34' 6.98" N, 13° 0' 35.96" E), in an area of 2.2 ha (Figure 1). The height of the buildings areas often come in conflicts with the human population, because they are considered threats to properties and health, and because they cause a perceived loss of aesthetics (Belant 1997, Rock 2005, as found also in this study. Mew Gulls are known to nest on roofs along the western coast of continental Europe from Norway to Portugal (Rock 2005). The nesting of gulls in urban areas may be associated with a good supply of food, high breeding success, and large amounts of suitable breeding habitats ( Jones 1985, Rock 2005, combined with the ability of gulls to adapt to human-altered environments (Belant 1997). In Sweden, the Mew Gull population has been largely stable since the late 1980s (Green et al. 2019), but we do not know of any estimates of the nesting population of Mew Gull in urban areas behaviour towards people to defend their young. The chairman perceived that there are more of them today than in previous years. The maintenance staff for the housing complex, who can access the nests, regularly take the eggs and puncture them to empty the contents, which ensures that the Mew Gulls remain on the nest, incubating the empty eggs, without producing any young. This way, they mitigate the negative effects experienced by the residents during the rearing of Mew Gull chicks.

Discussion
Some urban gull populations have increased dramatically in numbers (Rock 2005, Chávez-Villavicencio 2014, Kroc 2018. Gull populations that inhabit urban Ornis Svecica (ISSN 2003(ISSN -2633 is an open access, peer-reviewed scientific journal published in English and Swedish by BirdLife Sweden. It covers all aspects of ornithology, and welcomes contributions from scientists as well as non-professional ornithologists. Accepted articles are published at no charge to the authors. Read papers or make a submission at https://os.birdlife.se.
Ornis Svecica (ISSN 2003(ISSN -2633  of Sweden. There is also need for more behavioural studies related to the interaction between Mew Gulls and humans in urban areas. Such information would be useful for a proper management of urban populations and could help mitigating the perceived problems of urban breeding gulls.