title: Importance of accounting for detection heterogeneity when estimating abundance: the case of French wolves.
abstract: Assessing conservation strategies requires reliable estimates of abundance. Because detecting all individuals is most often impossible in free-ranging populations, estimation procedures have to account for a <1 detection probability. Capture-recapture methods allow biologists to cope with this issue of detectability. Nevertheless, capture-recapture models for open populations are built on the assumption that all individuals share the same detection probability, although detection heterogeneity among individuals has led to underestimating abundance of closed populations. We developed multievent capture-recapture models for an open population and proposed an associated estimator of population size that both account for individual detection heterogeneity (IDH). We considered a two-class mixture model with weakly and highly detectable individuals to account for IDH. In a noninvasive capture-recapture study of wolves we based on genotypes identified in feces and hairs, we found a large underestimation of population size (27% on average) occurred when IDH was ignored.
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175, Campus CNRS, 1919 Route de Mende, F-34293 Montpellier Cedex 5, France. sarah.cubaynes@cefe.cnrs.fr
authors.forename: Sarah
authors.initials: S
authors.lastname: Cubaynes
authors.forename: Roger
authors.initials: R
authors.lastname: Pradel
authors.forename: Rémi
authors.initials: R
authors.lastname: Choquet
authors.forename: Christophe
authors.initials: C
authors.lastname: Duchamp
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Gaillard
authors.forename: Jean-Dominique
authors.initials: JD
authors.lastname: Lebreton
authors.forename: Eric
authors.initials: E
authors.lastname: Marboutin
authors.forename: Christian
authors.initials: C
authors.lastname: Miquel
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Reboulet
authors.forename: Carole
authors.initials: C
authors.lastname: Poillot
authors.forename: Pierre
authors.initials: P
authors.lastname: Taberlet
authors.forename: Olivier
authors.initials: O
authors.lastname: Gimenez
mesh_terms: D000823:Animal Identification Systems; D000818:Animals; D001699:Biometry / Q000379:methods*; D005243:Feces; D005602:France; D006197:Hair; D015233:Models, Statistical; D011156:Population Density; D019596:Wolves