Camera trapping with capture-recapture analyses has provided estimates of the abundances of elusive species over the last two decades. Closed capture-recapture models (CR) based on the recognition of individuals and incorporating natural heterogeneity in capture probabilities are considered robust tools; however, closure assumption is often questionable and the use of an Mh jackknife estimator may fail in estimations of real abundance when the heterogeneity is high and data is sparse. A novel, spatially explicit capture-recapture (SECR) approach based on the location-specific capture histories of individuals overcomes the limitations of closed models. We applied both methods on a closed population of 16 critically endangered Western Derby elands in the fenced 1,060-ha Fathala reserve, Senegal. We analyzed the data from 30 cameras operating during a 66-day sampling period deployed in two densities in grid and line arrays. We captured and identified all 16 individuals in 962 trap-days. Abundances were estimated in the programs CAPTURE (models M0, Mh and Mh Chao) and R, package secr (basic Null and Finite mixture models), and compared with the true population size. We specified 66 days as a threshold in which SECR provides an accurate estimate in all trapping designs within the 7-times divergent density from 0.004 to 0.028 camera trap/ha. Both SECR models showed uniform tendency to overestimate abundance when sampling lasted shorter with no major differences between their outputs. Unlike the closed models, SECR performed well in the line patterns, which indicates promising potential for linear sampling of properly defined habitats of non-territorial and identifiable herbivores in dense wooded savanna conditions. The CR models provided reliable estimates in the grid and we confirmed the advantage of Mh Chao estimator over Mh jackknife when data appeared sparse. We also demonstrated the pooling of trapping occasions with an increase in the capture probabilities, avoiding violation of results.

Department of Animal Science and Food Processing Faculty of Tropical AgriSciences Czech University of Life Sciences Prague Kamýcká 129 165 21 Prague 6 Suchdol Prague Czech Republic

Department of Ecology Faculty of Environmental Sciences Czech University of Life Sciences Prague Kamýcká 129 165 21 Prague 6 Suchdol Prague Czech Republic

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Rexstad E, Burnham KP (1991) User's guide for interactive program CAPTURE: Color Cooperative Fish and Wildlife Research Unit.

Cooch E, White G (2009) Program MARK. A Gentle Introduction: 1–414.

Menkens GE, Anderson SH (1988) Estimation of Small-Mammal Population Size. Ecology 69: 1952–1959.

Borchers DL, Efford MG (2008) Spatially explicit maximum likelihood methods for capture-recapture studies. Biometrics 64: 377–385. PubMed

Karanth KU (1995) Estimating tiger Panthera tigris populations from camera-trap data using capture—recapture models. Biological Conservation 71: 333–338.

Karanth K, Nichols J (1998) Estimation of tiger densities in India using photographic captures and recaptures. Ecology 79: 2852–2862.

Wallace RB, Gomez H, Ayala G, Espinoza F (2003) Camera trapping for jaguar (Panthera onca) in the Tuichi Valley, Bolivia. Mastozoología Neotropical 10: 133–139.

Silver SC, Ostro LET, Marsh LK, Maffei L, Noss AJ, Kelly MJ, et al. (2004) The use of camera traps for estimating jaguar Panthera onca abundance and density using capture/recapture analysis. Oryx 38: 148–154.

Wang S, Macdonald D (2009) The use of camera traps for estimating tiger and leopard populations in the high altitude mountains of Bhutan. Biological Conservation 142: 606–613.

Trolle M, Kéry M (2003) Estimation of ocelot density in the Pantanal using capture-recapture analysis of camera-trapping data. Journal of mammalogy 84: 607–614.

Kelly MJ, Noss AJ, Di Bitetti MS, Maffei L, Arispe RL, Paviolo A, et al. (2008) Estimating Puma Densities from Camera Trapping across Three Study Sites: Bolivia, Argentina, and Belize. Journal of Mammalogy 89: 408–418.

Marnewick K (2008) Evaluating camera trapping as a method for estimating cheetah abundance in ranching areas. South African Journal of … 38: 59–65.

Weingarth K, Zimmermann F, Knauer F, Heurich M (2012) Evaluation of six digital camera models for the use in capture-recapture sampling of Eurasian Lynx (Lynx lynx). Waldökologie Landschaftsforschung und Naturschutz: 1–6.

Heilbrun RD, Silvy NJ, Peterson MJ, Tewes ME (2006) Estimating bobcat abundance using automatically triggered cameras. Wildlife Society Bulletin 34: 69–73.

Vanderhoff EN, Hodge A-M, Arbogast BS, Nilsson J, Knowles TW (2011) Abundance and activity patterns of the margay (Leopardus wiedii) at a mid-elevation site in the eastern andes of Ecuador. Mastozoología Neotropical 18: 271–279.

White GC (1982) Capture-recapture and removal methods for sampling closed populations: Los Alamos National Laboratory.

Harmsen BJ, Foster RJ, Doncaster CP (2010) Heterogeneous capture rates in low density populations and consequences for capture-recapture analysis of camera-trap data. Population Ecology 53: 253–259.

Larrucea ES, Brussard PF, Jaeger MM, Barrett RH (2007) Cameras, coyotes, and the assumption of equal detectability. Journal of Wildlife Management 71: 1682–1689.

Gompper M, Kays R, Ray J (2006) A comparison of noninvasive techniques to survey carnivore communities in northeastern North America Wildlife Society; … 34.

Harmsen BJ, Foster RJ, Silver S, Ostro L, Doncaster CP (2010) Differential use of trails by forest mammals and the implications for camera-trap studies: A case study from Belize. Biotropica 42: 126–133.

Burnham KP, Overton WS (1978) Estimation of the size of a closed population when capture probabilities vary among animals. Biometrika 65: 625–633.

Tobler MW, Carrillo-Percastegui SE, Leite Pitman R, Mares R, Powell G (2008) An evaluation of camera traps for inventorying large- and medium-sized terrestrial rainforest mammals. Animal Conservation 11: 169–178.

Chao A (1987) Estimating the population Size for Capture-Recapture Data with Unequal Catchability. Biometrics. PubMed

Foster RJ, Harmsen BJ (2012) A critique of density estimation from camera-trap data. The Journal of Wildlife Management 76: 224–236.

Chao A (1989) Estimating Population Size for Sparse Data in Capture-Recapture Experiments. Biometrics 45: 427–438.

Kendall WL (1999) Robustness of closed capture-recapture methods to violations of the closure assumption. Ecology 80: 2517–2525.

Efford MG (2011) Estimation of population density by spatially explicit capture–recapture analysis of data from area searches. Ecology 92: 2202–2207. PubMed

Dawson DK, Efford MG (2009) Bird population density estimated from acoustic signals. Journal of Applied Ecology 46: 1201–1209.

Marques TA, Thomas L, Martin SW, Mellinger DK, Jarvis S, Morrissey RP, et al. (2012) Spatially explicit capture-recapture methods to estimate minke whale density from data collected at bottom-mounted hydrophones. Journal of Ornithology 152: 445–455.

Tobler MW, Powell GVN (2013) Estimating jaguar densities with camera traps: Problems with current designs and recommendations for future studies. Biological Conservation 159: 109–118.

Anile S, Ragni B, Randi E, Mattucci F, Rovero F (2014) Wildcat population density on the Etna volcano, Italy: A comparison of density estimation methods. Journal of Zoology 293: 252–261.

Sharma RK, Jhala Y, Qureshi Q, Vattakaven J, Gopal R, Nayak K (2010) Evaluating capture-recapture population and density estimation of tigers in a population with known parameters. Animal Conservation 13: 94–103.

Gerber BD, Parmenter RR (2014) Spatial capture–recapture model performance with known small-mammal densities. Ecological Applications 25: 695–705. PubMed

Dumond M, Boulanger J, Paetkau D (2015) The estimation of grizzly bear density through hair-snagging techniques above the tree line. Wildlife Society Bulletin: 1–13.

Brandlová K, Mallon D, Hejcmanová P, Regnaut S, Jůnková Vymyslická P, Fedorova T, et al. (2013) Western Derby eland (Taurotragus derbianus derbianus) conservation strategy Prague: Czech University of Life Sciences Prague. 111 p.

Koláčková K, Hejcmanová P, Antonínová M, Brandl P (2011) Population management as a tool in the recovery of the critically endangered Western Derby eland Taurotragus derbianus in Senegal, Africa. Wildlife Biology 17: 299–310.

Barrier NF, Pradesh M (2013) Application of Photographic Capture-Recapture Sampling for Estimating Abundance of Indian Mouse Deer Moschiola indica. 8: 388–391.

Treves A, Mwima P, Plumptre AJ, Isoke S (2010) Camera-trapping forest-woodland wildlife of western Uganda reveals how gregariousness biases estimates of relative abundance and distribution. Biological Conservation 143: 521–528.

Bengsen AJ, Leung LKP, Lapidge SJ, Gordon IJ (2011) Using a general index approach to analyze camera-trap abundance indices. Journal of Wildlife Management 75: 1222–1227.

Li X, Buzzard P, Jiang X (2014) Habitat associations of four ungulates in mountain forests of southwest China, based on camera trapping and dung counts data. Population Ecology 56: 251–256.

O’Brien TG (2011) Abundance, density and relative abundance: a conceptual framework Camera Traps in Animal Ecology: Springer; pp. 71–96.

Efford MG, Fewster RM (2013) Estimating population size by spatially explicit capture-recapture. Oikos 122: 918–928.

Nežerková-Hejcmanová P, Hejcman M, Camara AA, Antonínová M, Pavlů V, Černý T, et al. (2005) Analysis of the herbaceous undergrowth of the woody savanna in the Fathala Reserve, Delta du Saloum National Park (Senegal). Belgian Journal of Botany: 119–128.

Nežerková P, Verner PH, Antonínová M (2004) The conservation programme of the Western giant eland (Taurotragus derbianus derbianus) in Senegal–Czech Aid Development Project Program ochrany antilopy Derbyho (Taurotragus derbianus derbianus) v Senegalu–projekt ãeské rozvojové pomoci. Soil Conservation.

Rovero F, Zimmermann F, Berzi D, Meek P (2013) " Which camera trap type and how many do I need?" A review of camera features and study designs for a range of wildlife research applications. Hystrix, the Italian Journal of Mammalogy 24: 148–156.

Renaud PC, Gueye MB, Hejcmanová P, Antonínová M, Samb M (2006) Inventaire aérien et terrestre de la faune et relevé des pressions au Parc National du Niokolo Koba.—Plan of Urgence, Report Annex A, August 2006. Dakar, APF, DPNS, Senegal: 74.

Schipper J (2007) Camera-trap avoidance by Kinkajous Potos fl avus: rethinking the “non-invasive” paradigm. Small Carnivore Conservation 36: 38–41.

Howe EJ, Obbard ME, Kyle CJ (2013) Combining data from 43 standardized surveys to estimate densities of female American black bears by spatially explicit capture-recapture. Population Ecology 55: 595–607.

Royle JA, Chandler RB, Gazenski KD, Graves TA (2013) Spatial capture-recapture models for jointly estimating population density and landscape connectivity. Ecology 94: 287–294. PubMed

Ivan JS, White GC, Shenk TM (2012) Using simulation to compare methods for estimating density from capture–recapture data. Ecology 94: 817–826.

Hillman J (1988) Home range and movement of the common eland (Taurotragus oryx Pallas 1766) in Kenya. African Journal of Ecology 26: 135–148.

DeFries R, Hansen A, Newton AC, Hansen MC (2005) Increasing isolation of protected areas in tropical forests over the past twenty years. Ecological Applications 15: 19–26.

Ogutu JO, Owen-Smith N, Piepho H-P, Kuloba B, Edebe J (2012) Dynamics of ungulates in relation to climatic and land use changes in an insularized African savanna ecosystem. Biodiversity and Conservation 21: 1033–1053.

Maffei L, Noss AJ, Silver SC, Kelly MJ (2011) Abundance/density case study: Jaguars in the Americas Camera traps in animal ecology: Springer; pp. 119–144.

Jachmann H (2002) Comparison of aerial counts with ground counts for large African herbivores. Journal of Applied Ecology 39: 841–852.

Redfern JV, Viljoen PC, Kruger JM, Getz WM (2002) Biases in estimating population size from an aerial census: A case study in the Kruger National Park, South Africa. South African Journal of Science 98: 455–461.

Cassey P, Mcardle BH (1999) An assessment of distance sampling techniques for estimating animal abundance. Environmetrics 10: 261–278.

Ogutu JO, Bhola N, Piepho HP, Reid R (2006) Efficiency of strip- and line-transect surveys of African savanna mammals. Journal of Zoology. pp. 149–160.

Barnes RFW (1999) Is there a future for elephants in West Africa? Mammal Review 29: 175–199.

Henschel P, Azani D, Burton C, Malanda G (2010) Lion status updates from five range countries in West and Central Africa. CatNEWS: 2006–2011.

Henschel P, Coad L, Burton C, Chataigner B, Dunn A, MacDonald D, et al. (2014) The lion in West Africa is critically endangered. PLoS ONE 9. PubMed PMC

Tchamba MN (1996) History and present status of the human/elephant conflict in the Waza-Logone region, Cameroon, West Africa. Biological Conservation. pp. 35–41.

Burton AC, Sam MK, Kpelle DG, Balangtaa C, Buedi EB, Brashares JS (2011) Evaluating persistence and its predictors in a West African carnivore community. Biological Conservation 144: 2344–2353.

Spatially restricted occurrence and low abundance as key tools for conservation of critically endangered large antelope in West African savannah