Siberian, or Amur tigr (Panthera tigris altaica)

Mohamed bin Zayed Species project number 10251168

An innovative way in which ungulates are managed in the Russian Far East is that the harvestable surplus is allocated to both humans and tigers.  Hunters are key stakeholders in tiger conservation in the Russian Far East as hunting is an important recreational and subsistence tradition in Russia, with over 60,000 registered hunters in the Russian Far East who rely on multiple use lands.  Wildlife management organizations are responsible for managing hunting, controlling poaching, and conducting surveys of game species on leased hunting territories which encompass about 85% of Amur tiger habitat.  Our results suggest that kill rates of Amur tigers may have recently declined, potentially as a result of methodological differences or lower prey densities.  As our research shows, tiger kill rates and consumption rates of ungulates may differ between seasons.  Therefore, extrapolating snow-tracking based kill-rate estimates over the entire year may lead to an overestimate of annual harvest of ungulates by both humans and tigers.  Finally, our results show promise for estimating kill rates and prey requirements of tigers in southern Asia where snow-tracking is not possible.  Given that most published estimates of kill rates of tigers are from Amur tigers (Table 2-1), GPS collars may provide a crucial tool to better understand prey requirements to conserve tiger populations.

The three primary threats associated with conservation of tigers are habitat loss, poaching, and prey depletion.  Other researchers have debated the relative importance of each (Chapron et al. 2008), but regardless, in order to meet the Global Tiger Recovery Program’s goals of doubling wild tiger numbers by 2022, maintaining adequate prey resources is crucial.  In many areas throughout Asia, tigers are decreasing or extirpated because of a lack of prey in areas with adequate potential habitat.  Therefore, there is a need to define minimum prey numbers needed for survival and reproduction.  Our energetics modeling shows a highly reproductive tigress will need 2–3 times more biomass than a solitary tigress.  This aligns with a recent definition of habitat quality that emphasizes adequate ungulate prey as the primary determinant of “high quality” habitat for tigers (Miquelle et al. 1996; Mitchell & Hebblewhite 2012; Mosser et al. 2009).

Our tiger energetics model is the first step towards calculating the prey thresholds required for tiger survival and reproduction.  Calculating the energetic demands facing tigers is an important step, but using our model to guide ungulate management to calculate minimum prey thresholds needed for tiger reproduction requires future work building on our energetics model.  Hayward et al. (2012) argued that tigers should select for prey species that yield a weight ratio of tiger to prey of 1:1.1.  In the Russian Far East, prey items that meet this criterion would be wild boar, red deer, and potentially sika deer.  Availability and abundance estimates of these preferred prey populations are also needed to estimate the prey thresholds required for survival and reproduction.  Unfortunately, rigorous estimates of prey availability are lacking throughout much of tiger range.  Finally, encounter rates of preferred prey species are critical in determining prey selectivity and must be included in any estimate of prey thresholds (Huggard 1993).

As displayed with data from the Sundarbans, our tiger energetics model is adjustable for tiger populations throughout their range.  Currently, many countries in Southeast Asia are attempting to conserve or re-establish viable tiger populations in the face of the densest and rapidly growing human populations.  Using our energetics model, knowledge of the proportion of each prey species in tigers’ diet, and estimated prey abundance will help determine if sufficient prey, their associated density, and overall area requirements exist to support tiger survival and reproduction.  It is unrealistic to believe tigers can survive and successfully reproduce in landscapes suffering from the empty forest syndrome or that a tigress with 4 cubs could obtain the 425 musk deer needed per year under our single prey scenario.  The conservation implications of this research will facilitate conservation efforts on protecting preferred prey populations as a key component of tiger conservation.

We have completed data collection and analyses for our two-year research project.  Support from Mohamed bin Zayed Species Conservation Fund has been critical to our recent progress, and the potential for the conservation success of our work. The remaining work involves publishing this research in scientific journals, giving presentations on the conservation implications of the work, and striving to change regional policy to incorporate our new findings.  In May 2012, Clay Miller successfully defended this research as part of his requirements for a Master of Science in Wildlife Biology from the University of Montana.  During May, Clay travelled to New York City to give similar hour-long presentations at the headquarters of both Panthera and the Wildlife Conservation Society. Clay Miller will travel to Russia in late July 2012 to present our findings to our colleagues and staff at the Zapovednik where this work was conducted. In August, Clay will continue to Bangalore, India where he will present these findings at the Biodiversity Asia 2012 scientific conference. Biodiversity Asia 2012 will bring together researchers, policy makers, managers, students, teachers, NGOs, activists, and others working towards the conservation of Asia’s biodiversity. Funding support from Mohamed bin Zayed Species Conservation Fund was and will continue to be acknowledged in all of our presentations and publications.