title: The spatial distribution of Mustelidae in France.
abstract: We estimated the spatial distribution of 6 Mustelidae species in France using the data collected by the French national hunting and wildlife agency under the "small carnivorous species logbooks" program. The 1500 national wildlife protection officers working for this agency spend 80% of their working time traveling in the spatial area in which they have authority. During their travels, they occasionally detect dead or living small and medium size carnivorous animals. Between 2002 and 2005, each car operated by this agency was equipped with a logbook in which officers recorded information about the detected animals (species, location, dead or alive, date). Thus, more than 30000 dead or living animals were detected during the study period. Because a large number of detected animals in a region could have been the result of a high sampling pressure there, we modeled the number of detected animals as a function of the sampling effort to allow for unbiased estimation of the species density. For dead animals -- mostly roadkill -- we supposed that the effort in a given region was proportional to the distance traveled by the officers. For living animals, we had no way to measure the sampling effort. We demonstrated that it was possible to use the whole dataset (dead and living animals) to estimate the following: (i) the relative density -- i.e., the density multiplied by an unknown constant -- of each species of interest across the different French agricultural regions, (ii) the sampling effort for living animals for each region, and (iii) the relative detection probability for various species of interest.
authors: Office national de la chasse et de la faune sauvage, Direction des études et de la recherche, Saint Benoist, BP 20. 78612 Le Perray en Yvelines, France.
authors: Clément
authors: C
authors: Calenge
authors: Statistics, UR1052, Domaine Saint Maurice 67, Allée des chênes CS 60094 F-84143 Montfavet cedex, France.
authors: Joël
authors: J
authors: Chadoeuf
authors: CMAP, UMR 7641, Ecole Polytechnique, Palaiseau, France-Laboratoire de Mathématiques d'Orsay, UMR 8628, Université Paris-Sud, Orsay, France.
authors: Christophe
authors: C
authors: Giraud
authors: UR 341 MIA, INRA, F78352, Jouy-en-Josas, France.
authors: Sylvie
authors: S
authors: Huet
authors: CESCO, UMR 7204, MNHN-CNRS-UPMC, CP51, 55 rue Buffon, 75005 Paris, France.
authors: Romain
authors: R
authors: Julliard
authors: INRA-Unité BioSp. Domaine Saint-Paul, Site Agroparc, 84914 Avignon Cedex 9, France.
authors: Pascal
authors: P
authors: Monestiez
authors: IRSTEA, UR MALY, centre de Lyon-Villeurbanne F-69626 Villeurbanne, France.
authors: Jérémy
authors: J
authors: Piffady
authors: CEBC, UMR 7372-CNRS/Univ La Rochelle, 79360 Villiers en Bois, France.
authors: David
authors: D
authors: Pinaud
authors: Office national de la chasse et de la faune sauvage, Direction des études et de la recherche, Saint Benoist, BP 20. 78612 Le Perray en Yvelines, France.
authors: Sandrine
authors: S
authors: Ruette
mesh_terms: D000383:Agriculture; D000818:Animals; D005602:France; D005843:Geography; D008954:Models, Biological; D045969:Mustelidae / Q000502:physiology*; D011156:Population Density; D015203:Reproducibility of Results; D013045:Species Specificity