title: Are white storks addicted to junk food? Impacts of landfill use on the movement and behaviour of resident white storks (Ciconia ciconia) from a partially migratory population.
abstract: BACKGROUND
  The migratory patterns of animals are changing in response to global environmental change with many species forming resident populations in areas where they were once migratory. The white stork (Ciconia ciconia) was wholly migratory in Europe but recently guaranteed, year-round food from landfill sites has facilitated the establishment of resident populations in Iberia. In this study 17 resident white storks were fitted with GPS/GSM data loggers (including accelerometer) and tracked for 9.1 ± 3.7 months to quantify the extent and consistency of landfill attendance by individuals during the non-breeding and breeding seasons and to assess the influence of landfill use on daily distances travelled, percentage of GPS fixes spent foraging and non-landfill foraging ranges.
  
  
  RESULTS
  Resident white storks used landfill more during non-breeding (20.1 % ± 2.3 of foraging GPS fixes) than during breeding (14.9 % ± 2.2). Landfill attendance declined with increasing distance between nest and landfill in both seasons. During non-breeding a large percentage of GPS fixes occurred on the nest throughout the day (27 % ± 3.0 of fixes) in the majority of tagged storks. This study provides first confirmation of year-round nest use by resident white storks. The percentage of GPS fixes on the nest was not influenced by the distance between nest and the landfill site. Storks travelled up to 48.2 km to visit landfills during non-breeding and a maximum of 28.1 km during breeding, notably further than previous estimates. Storks nesting close to landfill sites used landfill more and had smaller foraging ranges in non-landfill habitat indicating higher reliance on landfill. The majority of non-landfill foraging occurred around the nest and long distance trips were made specifically to visit landfill.
  
  
  CONCLUSIONS
  The continuous availability of food resources on landfill has facilitated year-round nest use in white storks and is influencing their home ranges and movement behaviour. White storks rely on landfill sites for foraging especially during the non-breeding season when other food resources are scarcer and this artificial food supplementation probably facilitated the establishment of resident populations. The closure of landfills, as required by EU Landfill Directives, will likely cause dramatic impacts on white stork populations.
authors.affiliation: School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK.
authors.forename: Nathalie I
authors.initials: NI
authors.lastname: Gilbert
authors.affiliation: School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK ; Centre for Ecology, Evolution and Environmental Changes (Ce3C), Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Correia
authors.affiliation: Centro de Ecologia Aplicada Prof. Baeta Neves and InBio, Rede de Investigacão em Biodiversidade e Biologia Evolutiva, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal.
authors.forename: João Paulo
authors.initials: JP
authors.lastname: Silva
authors.affiliation: School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK.
authors.forename: Carlos
authors.initials: C
authors.lastname: Pacheco
authors.affiliation: School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK ; Centro de Ecologia Aplicada Prof. Baeta Neves and InBio, Rede de Investigacão em Biodiversidade e Biologia Evolutiva, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal.
authors.forename: Inês
authors.initials: I
authors.lastname: Catry
authors.affiliation: British Trust for Ornithology, BTO, The Nunnery, Thetford, Norfolk IP24 2PU UK.
authors.forename: Philip W
authors.initials: PW
authors.lastname: Atkinson
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK.
authors.forename: Jenny A
authors.initials: JA
authors.lastname: Gill
authors.affiliation: School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK.
authors.forename: Aldina M A
authors.initials: AM
authors.lastname: Franco
keywords: Adaptation; Avian; Birds; Foraging behaviour; Foraging ecology; Movement ecology; Partial migration; Residency; Tracking; Utilization distribution