title: Mapping the global distribution of livestock.
abstract: Livestock contributes directly to the livelihoods and food security of almost a billion people and affects the diet and health of many more. With estimated standing populations of 1.43 billion cattle, 1.87 billion sheep and goats, 0.98 billion pigs, and 19.60 billion chickens, reliable and accessible information on the distribution and abundance of livestock is needed for a many reasons. These include analyses of the social and economic aspects of the livestock sector; the environmental impacts of livestock such as the production and management of waste, greenhouse gas emissions and livestock-related land-use change; and large-scale public health and epidemiological investigations. The Gridded Livestock of the World (GLW) database, produced in 2007, provided modelled livestock densities of the world, adjusted to match official (FAOSTAT) national estimates for the reference year 2005, at a spatial resolution of 3 minutes of arc (about 5×5 km at the equator). Recent methodological improvements have significantly enhanced these distributions: more up-to date and detailed sub-national livestock statistics have been collected; a new, higher resolution set of predictor variables is used; and the analytical procedure has been revised and extended to include a more systematic assessment of model accuracy and the representation of uncertainties associated with the predictions. This paper describes the current approach in detail and presents new global distribution maps at 1 km resolution for cattle, pigs and chickens, and a partial distribution map for ducks. These digital layers are made publically available via the Livestock Geo-Wiki (http://www.livestock.geo-wiki.org), as will be the maps of other livestock types as they are produced.
authors.affiliation: Livestock Systems and Environment Research Theme (LSE), International Livestock Research Institute (ILRI), Nairobi, Kenya; Animal Production and Health Division (AGA), Food and Agriculture Organization of the United Nations (FAO), Rome, Italy.
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Robinson
authors.affiliation: Environmental Research Group Oxford (ERGO) - Department of Zoology, University of Oxford, Oxford, United Kingdom.
authors.forename: G R William
authors.initials: GR
authors.lastname: Wint
authors.affiliation: Animal Production and Health Division (AGA), Food and Agriculture Organization of the United Nations (FAO), Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Conchedda
authors.affiliation: Biological Control and Spatial Ecology, Université Libre de Bruxelles, Brussels, Belgium; Fonds National de la Recherche Scientifique, Brussels, Belgium; Department of Ecology and Evolutionary - Biology Department, Princeton University, Princeton, New Jersey, United States of America; Princeton Environmental Institute, Princeton, New Jersey, United States of America.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Van Boeckel
authors.affiliation: Animal Production and Health Division (AGA), Food and Agriculture Organization of the United Nations (FAO), Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Ercoli
authors.affiliation: Animal Production and Health Division (AGA), Food and Agriculture Organization of the United Nations (FAO), Rome, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Palamara
authors.affiliation: Animal Production and Health Division (AGA), Food and Agriculture Organization of the United Nations (FAO), Rome, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Cinardi
authors.affiliation: Animal Production and Health Division (AGA), Food and Agriculture Organization of the United Nations (FAO), Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: D'Aietti
authors.affiliation: Spatial Ecology and Epidemiology Group - Department of Zoology, University of Oxford, Oxford, United Kingdom; Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Simon I
authors.initials: SI
authors.lastname: Hay
authors.affiliation: Biological Control and Spatial Ecology, Université Libre de Bruxelles, Brussels, Belgium; Fonds National de la Recherche Scientifique, Brussels, Belgium.
authors.forename: Marius
authors.initials: M
authors.lastname: Gilbert
mesh_terms: D000818:Animals; D002417:Cattle; D002645:Chickens; D004372:Ducks; D005523:Food Supply; D005843:Geography; D058751:Livestock; D008962:Models, Theoretical; D013552:Swine