title: Scent Lure Effect on Camera-Trap Based Leopard Density Estimates.
abstract: Density estimates for large carnivores derived from camera surveys often have wide confidence intervals due to low detection rates. Such estimates are of limited value to authorities, which require precise population estimates to inform conservation strategies. Using lures can potentially increase detection, improving the precision of estimates. However, by altering the spatio-temporal patterning of individuals across the camera array, lures may violate closure, a fundamental assumption of capture-recapture. Here, we test the effect of scent lures on the precision and veracity of density estimates derived from camera-trap surveys of a protected African leopard population. We undertook two surveys (a 'control' and 'treatment' survey) on Phinda Game Reserve, South Africa. Survey design remained consistent except a scent lure was applied at camera-trap stations during the treatment survey. Lures did not affect the maximum movement distances (p = 0.96) or temporal activity of female (p = 0.12) or male leopards (p = 0.79), and the assumption of geographic closure was met for both surveys (p >0.05). The numbers of photographic captures were also similar for control and treatment surveys (p = 0.90). Accordingly, density estimates were comparable between surveys (although estimates derived using non-spatial methods (7.28-9.28 leopards/100km2) were considerably higher than estimates from spatially-explicit methods (3.40-3.65 leopards/100km2). The precision of estimates from the control and treatment surveys, were also comparable and this applied to both non-spatial and spatial methods of estimation. Our findings suggest that at least in the context of leopard research in productive habitats, the use of lures is not warranted.
authors.affiliation: Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Tubney, Oxfordshire, United Kingdom.
authors.forename: Alexander Richard
authors.initials: AR
authors.lastname: Braczkowski
authors.affiliation: Panthera, 8 West 40th Street,18th Floor, New York, New York, United States of America.|Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa.
authors.forename: Guy Andrew
authors.initials: GA
authors.lastname: Balme
authors.affiliation: Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Tubney, Oxfordshire, United Kingdom.|Ruaha Carnivore Project, Iringa, Tanzania.
authors.forename: Amy
authors.initials: A
authors.lastname: Dickman
authors.affiliation: Panthera, 8 West 40th Street,18th Floor, New York, New York, United States of America.|School of Life Sciences, University of Kwazulu-Natal, Westville Campus, Durban, South Africa.
authors.forename: Julien
authors.initials: J
authors.lastname: Fattebert
authors.affiliation: Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Tubney, Oxfordshire, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Johnson
authors.affiliation: Panthera, 8 West 40th Street,18th Floor, New York, New York, United States of America.
authors.forename: Tristan
authors.initials: T
authors.lastname: Dickerson
authors.affiliation: Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Tubney, Oxfordshire, United Kingdom.
authors.forename: David Whyte
authors.initials: DW
authors.lastname: Macdonald
authors.affiliation: Panthera, 8 West 40th Street,18th Floor, New York, New York, United States of America.
authors.forename: Luke
authors.initials: L
authors.lastname: Hunter
mesh_terms: D000818:Animals; D003247:Conservation of Natural Resources; D045989:Felidae / Q000254:growth & development*; D005260:Female; D008297:Male; D009812:Odorants; D011156:Population Density; D013019:South Africa