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Riau Province in central Sumatra, with its peatland, lowland, and montane forest habitats, was once a stronghold for Sumatran tiger (Panthera tigris sumatrae) populations. Today, Riau may have one of the highest deforestation rates in the world and wildlife populations are dwindling, with natural forest now comprising approximately only 18% of the province, mostly contained within protected areas. Agriculture (acacia, rubber, and oil palm) makes up the majority of Riau's land cover and deforestation for the creation of new plantations is rampant. Natural forest and tigers still remain in Bukit Tigapuluh National Park and Rimbang Baling Wildlife Reserve, which remain connected to tiger populations in montane forest on the western edge of Sumatra. In this study, using freely available Landsat imagery and a maximum likelihood classification algorithm, we create land cover maps for central Sumatra from 2002 to 2016. We then use current land cover, elevation, and slope variables to predict changes from forest to plantation from 2016 to 2050 at five year intervals using a multilayer perceptron neural network. Finally, we compare connectivity based on a 100 km distance threshold (based on potential tiger dispersal) across the landscape and across years. Land cover maps had 80-90% accuracy, and we predict forest in Tesso Nilo and the western edge of the study area to be lost by 2050 given current rates of deforestation. Our connectivity analysis shows that Tesso Nilo and the area between Rimbang Baling and Bukit Tigapuluh are important components for maintaining connectivity throughout the study area. Focusing conservation and rehabilitation efforts on forests close to plantations in flat areas, including Tesso Nilo, is necessary to maintain forests and increase connectivity in Riau to ensure future habitat connectivity for survival of tigers and Sumatra's other diverse endemic species.

Sumatran tigers (Panthera tigris sumatrae) are a critically endangered carnivore restricted to the island of Sumatra, and like many other large mammals on the Indonesian archipelago, they are threatened by high levels of poaching and widespread habitat degradation. Here, we conduct the first range-wide assessment of Sumatran tiger genetics using scat surveys and show that the wild population retains levels of genetic heterozygosity comparable to mainland tigers. However, the population also exhibits signs of subdivision due to the unprecedented rates of deforestation and land conversion in the last 30–40 years. The fact that this subspecies retains such levels of heterozygosity despite high rates of habitat loss and increasing isolation suggests a form of genetic extinction debt with an elevated risk of extinction if no action is taken within the next 30–100 years (see Kenney et al., 2014 ). However, the inherent time delay in extinction debt provides opportunities for conservation if habitat quality can be improved and connections between existing population fragments can be made. Our study highlights the importance of genetic studies for providing baseline information to improve the population management of highly threatened carnivore species. Mitigating further habitat degradation and expansion of oil palm and other cash crops in this region would improve the viability not only of Sumatran tiger populations, but of other threatened large mammal species as well.

Fatal injuries caused by attacks by large wild cats are extremely rare in forensic medical practice in Europe. There are very few cases described in the forensic medical literature concerning incidents in zoos similar to the tiger attack on a 58-year-old male zoo employee that we present here. While preparing a runway for tigers, the man was attacked by a male Sumatran tiger. Another zoo employee was an eyewitness to the accident; in his testimony he described the sequence of events in detail. The autopsy showed the injuries typical of a tiger attack: traces of claws and canine teeth indicating that the victim of the attack was knocked down from behind, along with deep and extensive fatal wounds to the neck. The injuries were inflicted by means of a compound mechanism: tissues were penetrated by the animal's canines, crushed with great force (transfixing injury), and violently distended. The skin revealed four characteristic deep wounds caused by canines as well as bite marks resulting from the action of six incisors. The neck area revealed extensive damage, including torn muscles, the esophagus and trachea, large blood vessels of the neck, and fractures of vertebrae C2 and C5 with internal channels resulting directly from penetration by the animal's canines. The mechanism of distension, as a result of the animal jerking its head after biting the victim in the neck, produced a complete tear of the spine and the vertebral arteries, as well as an intramural rupture of the carotid arteries which has never been described before. In the interests of a detailed assessment of bone damage, the cervical spine was macerated. The applied autopsy techniques and detailed analysis of injuries enabled us to demonstrate the compound mechanism that inflicted them, combining penetration of tissues by the canines, crushing, and distension.

In Osnabruck zoo, the opening of a new Sumatran tiger enclosure, an extension to the former tiger facility, took place in March 2014. Installed in the new enclosure were two young tigers and they were observed in the first weeks after their arrival. The focus was on the use of the enclosure and the tigers approach to each other. In addition, their general behaviour was recorded and examined to see whether they developed any stereotypical behaviour types. Data collection took place from 25th March to 11th July 2014 (in total 120 hours of observation, 60 hours per tiger). The animals were observed by focus animal sampling. The central focus of the observations was laid on stress indicating behaviour and approaches to each other. At the beginning, the female tiger (Diana) showed some stereotypic behaviour (pacing), but this was not established and vanished after a few weeks. Following introduction into the outdoor enclosure, the tigers interacted mostly in friendly ways. There is no indication that one tiger was overly active in approaching the other, as expressed by approach-leave-coefficient.

Ecosystem services have clear promise to help identify and protect priority areas for biodiversity. To leverage them effectively, practitioners must conduct timely analyses at appropriate scales, often with limited data. Here we use simple spatial analyses on readily available datasets to compare the distribution of five ecosystem services with tiger habitat in central Sumatra. We assessed services and habitat in 2008 and the changes in these variables under two future scenarios: a conservation-friendly Green Vision, and a Spatial Plan developed by the Indonesian government. In 2008, the range of tiger habitat overlapped substantially with areas of high carbon storage and sediment retention, but less with areas of high water yield and nutrient retention. Depending on service, location and spatial grain of analysis, there were both gains and losses from 2008 to each scenario; however, aggregate provision of each ecosystem service (except water yield) and total area of tiger habitat were higher in the Vision than the Plan, likely driven by an increase in forest cover in the Vision. Sub-watersheds with high levels of several ecosystem services contained substantially more tiger habitat than random subsets of sub-watersheds, suggesting that prioritizing ecosystem services could benefit tiger conservation. Our analyses provided input to government-led spatial planning and strategic environmental assessments in the study area, indicating that even under time and data constraints, policy-relevant assessments of multiple ecosystem services are feasible.

The expensive computational cost of sensitivity analyses has hampered the use of these techniques for analysing individual-based models in ecology. A relatively cheap computational cost, referred to as the Morris method, was chosen to assess the relative effects of all parameters on the model’s outputs and to gain insights into predator–prey systems. Structure and results of the sensitivity analysis of the Sumatran tiger model – the Panthera Population Persistence (PPP) and the Notonecta foraging model (NFM) – were compared. Both models are based on a general predation cycle and designed to understand the mechanisms behind the predator–prey interaction being considered. However, the models differ significantly in their complexity and the details of the processes involved. In the sensitivity analysis, parameters that directly contribute to the number of prey items killed were found to be most influential. These were the growth rate of prey and the hunting radius of tigers in the PPP model as well as attack rate parameters and encounter distance of backswimmers in the NFM model. Analysis of distances in both of the models revealed further similarities in the sensitivity of the two individual-based models. The findings highlight the applicability and importance of sensitivity analyses in general, and screening design methods in particular, during early development of ecological individual-based models. Comparison of model structures and sensitivity analyses provides a first step for the derivation of general rules in the design of predator–prey models for both practical conservation and conceptual understanding.

The response of most large carnivores to selective logging is poorly understood. On the one hand, selective logging may represent loss of important habitat, yet, on the other hand, selective logging may increase browse availability for a terrestrial ungulate prey base, thereby indirectly benefiting large carnivores. Using a camera trap-based sampling method, we estimate tiger density in two primary-selectively logged forest areas that straddle Kerinci Seblat National Park, Sumatra. We then investigate potential differences between the habitat use of tigers: within these study areas and forest types; and, within the finer-scale landscape features associated with these covariates. Across the mixed forest study areas, tiger density estimates (adult individuals/100 km2 ± S.E.) of 2.95 ± 0.56 and 1.55 ± 0.34 were produced. However, within these areas, tigers showed a preference for primary over degraded forest, and this was related to the greater accessibility of degraded forest sites to people, e.g., through their proximity to roads. Presently, the majority of Sumatran tigers occur within large tracts of primary forest, but these extend outside of the island’s protected area borders, and these unprotected forests are especially at risk from the high levels of deforestation in Sumatra. As forest is cleared, previously remote, and therefore safer, tracts of primary forest become accessible and, eventually, degraded. Yet, from our study, degraded forest in combination with primary forest supported sufficiently high tiger densities and can, therefore, make an important contribution to tiger conservation. It is therefore essential to lessen the detrimental effects of accessibility through increasing law enforcement and destroying ex-logging roads.

Genome resource banks (GRBs) and assisted reproductive techniques are increasingly recognized as useful tools for the management and conservation of biodiversity, including endangered species. Cryotechnology permits long-term storage of valuable genetic material. Although, the actual application to endangered species management requires technical knowledge about sperm freezing and thawing, a systematic understanding of the quantitative impacts of various germ plasm storage and use scenarios is also mandatory. In this study, various GRB strategies were analyzed using the historical data from three managed populations of endangered species with varied pedigrees (Eld's deer, Przewalski's horse, and Sumatran tiger). The following types of sperm banks were assessed: (1) a “Wild Bank” consisting of sperm (i.e., genes) from 5 to 10 males unrelated to the managed population and to each other; and (2) a “Best Male” bank containing sperm from only the most genetically valuable males alive in the ex situ population at the time the bank was established. These different bank types were then used to evaluate the effectiveness of different bank usage frequencies. The efficiency of each scenario was assessed by examining the level of inbreeding and gene diversity in the population. Overall, a sperm usage frequency of five times per year was determined to be the most efficient and “wild banks” were highly successful at enhancing genetic diversity. The value of a GRB established from the ex situ population depends on how closely related the banked males are to future generations. A GRB will have significantly less benefit when banked males also produce many successful offspring, or when donors are already genetically over-represented in the population at the time of establishing the GRB.