title: Dynamics of a low-density tiger population in Southeast Asia in the context of improved law enforcement.
abstract: Recovering small populations of threatened species is an important global conservation strategy. Monitoring the anticipated recovery, however, often relies on uncertain abundance indices rather than on rigorous demographic estimates. To counter the severe threat from poaching of wild tigers (Panthera tigris), the Government of Thailand established an intensive patrolling system in 2005 to protect and recover its largest source population in Huai Kha Khaeng Wildlife Sanctuary. Concurrently, we assessed the dynamics of this tiger population over the next 8 years with rigorous photographic capture-recapture methods. From 2006 to 2012, we sampled across 624-1026 km(2) with 137-200 camera traps. Cameras deployed for 21,359 trap days yielded photographic records of 90 distinct individuals. We used closed model Bayesian spatial capture-recapture methods to estimate tiger abundances annually. Abundance estimates were integrated with likelihood-based open model analyses to estimate rates of annual and overall rates of survival, recruitment, and changes in abundance. Estimates of demographic parameters fluctuated widely: annual density ranged from 1.25 to 2.01 tigers/100 km(2) , abundance from 35 to 58 tigers, survival from 79.6% to 95.5%, and annual recruitment from 0 to 25 tigers. The number of distinct individuals photographed demonstrates the value of photographic capture-recapture methods for assessments of population dynamics in rare and elusive species that are identifiable from natural markings. Possibly because of poaching pressure, overall tiger densities at Huai Kha Khaeng were 82-90% lower than in ecologically comparable sites in India. However, intensified patrolling after 2006 appeared to reduce poaching and was correlated with marginal improvement in tiger survival and recruitment. Our results suggest that population recovery of low-density tiger populations may be slower than anticipated by current global strategies aimed at doubling the number of wild tigers in a decade.
authors.affiliation: Department of National Parks, Wildlife and Plant Conservation, Paholyotin Road, Chatuchak, Bangkok, 10110, Thailand.
authors.forename: Somphot
authors.initials: S
authors.lastname: Duangchantrasiri
authors.affiliation: Wildlife Conservation Society, Thailand Program, 55/295 Muangthong Thani 5, Chaengwattana Road, Pakkred, Nonthaburi, 10210, Thailand.
authors.forename: Mayuree
authors.initials: M
authors.lastname: Umponjan
authors.affiliation: Department of National Parks, Wildlife and Plant Conservation, Paholyotin Road, Chatuchak, Bangkok, 10110, Thailand.
authors.forename: Saksit
authors.initials: S
authors.lastname: Simcharoen
authors.affiliation: Wildlife Conservation Society, Thailand Program, 55/295 Muangthong Thani 5, Chaengwattana Road, Pakkred, Nonthaburi, 10210, Thailand.|Faculty of Forestry, Department of Conservation, Kasetsart University, Bangkok, 10900, Thailand.
authors.forename: Anak
authors.initials: A
authors.lastname: Pattanavibool
authors.affiliation: Department of National Parks, Wildlife and Plant Conservation, Paholyotin Road, Chatuchak, Bangkok, 10110, Thailand.
authors.forename: Soontorn
authors.initials: S
authors.lastname: Chaiwattana
authors.affiliation: Department of National Parks, Wildlife and Plant Conservation, Paholyotin Road, Chatuchak, Bangkok, 10110, Thailand.
authors.forename: Sompoch
authors.initials: S
authors.lastname: Maneerat
authors.affiliation: Centre for Wildlife Studies, 1669, 31st Cross, 16th Main, Banashankari 2nd Stage, Bengaluru, 560 070, India.|Wildlife Conservation Society, India Program, 1669, 31st Cross, 16th Main, Banashankari 2nd Stage, Bengaluru, 560 070, India.
authors.forename: N Samba
authors.initials: NS
authors.lastname: Kumar
authors.affiliation: Centre for Wildlife Studies, 1669, 31st Cross, 16th Main, Banashankari 2nd Stage, Bengaluru, 560 070, India.
authors.forename: Devcharan
authors.initials: D
authors.lastname: Jathanna
authors.affiliation: Centre for Wildlife Studies, 1669, 31st Cross, 16th Main, Banashankari 2nd Stage, Bengaluru, 560 070, India.
authors.forename: Arjun
authors.initials: A
authors.lastname: Srivathsa
authors.affiliation: Centre for Wildlife Studies, 1669, 31st Cross, 16th Main, Banashankari 2nd Stage, Bengaluru, 560 070, India.|Wildlife Conservation Society, Global Conservation Program, 2300 Southern Boulevard, Bronx, NY, 10460, U.S.A.
authors.forename: K Ullas
authors.initials: KU
authors.lastname: Karanth
mesh_terms: D000818:Animals; D001210:Asia, Southeastern; D001499:Bayes Theorem; D003247:Conservation of Natural Resources / Q000331:legislation & jurisprudence*; D006801:Humans; D007194:India; D035846:Law Enforcement; D016013:Likelihood Functions; D011157:Population Dynamics; D013785:Thailand; D046010:Tigers
keywords: abundance estimation; camera traps; carnivores; carnívoros; dinámicas poblacionales; estimación de la abundancia; exceso de caza; modelos espaciales de captura-recaptura; overhunting; patrolling; patrullaje; population dynamics; spatial capture-recapture models; trampas cámara