A comparison of food habits and prey preferences of Amur tiger(Panthera tigris altaica)at the southwest Primorskii Krai in Russia and Hunchun in China

A small,isolated Amur tiger population ranges across the southwest Primorskii Krai region in Russia and Hunchun region in China.Many individuals,with“dual nationality,”cross the border frequently.Formulating effective conservation strategies requires a clear understanding of tiger food requirements in both countries.While the diets of tigers ranging in Russia is clearly understood,little is known of the tigers’feeding habits in China..We used scat analysis combined with data on the abundance of 4 prey species to examine Amur tiger diet and prey preferences in Hunchun.We examined 53 tiger scat samples from 2011 to 2016 and found that tigers preyed on 12 species(11 species in winter),4 of which were domestic animals with 33.58%biomass contribution;this was the first record of Amur tigers eating lynx in this area.Tigers showed a strong preference for wild boar(Jacobs index:+0.849),which were also the most frequently consumed prey,and a strong avoidance of roe deer(Jacobs index:–0.693).On the Russian side,domestic animals(just dog)were rarely found in tiger scat,and tigers did not show strong avoidance of roe deer,but of sika deer.We also found red deer footprints during winter surveys and that tigers ate red deer on the Chinese side,while there was no record of red deer feeding on the Russian side.Reducing or eliminating human disturbance,such as grazing,is essential to recovering tiger prey and habitat in this area and the Sino–Russian joint ungulate annual survey is indispensable for prey estimates of this small,isolated Amur tiger population.

The omnivorous predator Macrolophus pygmaeus,a good candidate for the control of both greenhouse whitefly and poinsettia thrips on gerbera plants

The poinsettia thrips Echinothrips americanus Morgan is a relatively new pest that has spread rapidly worldwide and causes serious damage in both vegetable and ornamental plants.In this study,we investigated if and how effective this pest can be controlled in gerbera by the omnivorous predator Macrolophus pygmaeus(Rambur).Because herbivores on plants can interact through a shared predator,we also investigated how poinsettia thrips control is affected by the presence of the greenhouse whitefly Trialeurodes vaporariorum(Westwood),a pest that commonly coexists with E.americanus in gerbera.In laboratory studies,we found that the predator M.pygmaeus fed on both pests when offered together.Olfactometer tests showed a clear preference of the predators for plants infested by whiteflies but not by thrips.In a greenhouse experiment,densities of both pests on single gerbera plants were reduced to very low levels by the predator,either with both pests present together or alone.Hence,predator‐mediated effects between whiteflies and thrips played only a minor role.The plant feeding of the shared predator probably reduced the dependence of predator survival and reproduction on the densities of the two pests,thereby weakening potential predator‐mediated effects.Thus,M.pygmaeus is a good candidate for biological control of both pests in gerbera.However,further research is needed to investigate pest control at larger scales,when the pests can occur on different plants.