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The small Indian mongoose, Urva auropunctata, is one of the most notorious invasive species in the world. In Japan, the mongoose was introduced to Amami, Kyushu (Kiire region), and Okinawa Islands. Currently, an eradication program for the Amami population is proving successful. To prevent reinvasion and conserve biodiversity, it would be advantageous to investigate the origin and dispersal history of introduced mongoose populations in Japan. We determined the mitochondrial genome of a mongoose from the Okinawa population and confirmed that the systematic status of the mongoose is Urva auropunctata. We also found two haplotypes of cytochrome b in the Amami population, one of which is common among the Okinawa, Amami, and Kiire populations. Based on our microsatellite analysis, the three populations were genetically different from each other. Furthermore, with a low pairwise FST value, the Kiire population was closer to the Okinawa than the Amami population. Our results suggest that the Okinawa population could be the source of the Amami and Kiire populations. These results align with historical records of mongoose in Japan and clarify its genetic status. Our results should aid the prediction of the pathway through which a new invasion will likely occur.

Biological invasions represent a key threat to insular systems and have pronounced impacts across environments and economies. The ecological impacts have received substantial focus, but the socioeconomic impacts are poorly synthesized across spatial and temporal scales. We used the InvaCost database, the most comprehensive assessment of published economic costs of invasive species, to assess economic impacts on islands worldwide. We analyzed socioeconomic costs across differing expenditure types and examined temporal trends across islands that differ in their political geography-island nation states, overseas territories, and islands of continental countries. Over US$36 billion in total costs (including damages and management) has occurred on islands from 1965 to 2020 due to invasive species' impacts. Nation states incurred the greatest total and management costs, and islands of continental countries incurred costs of similar magnitude, both far higher than those in overseas territories. Damage-loss costs were significantly lower, but with qualitatively similar patterns across differing political geographies. The predominance of management spending differs from the pattern found for most countries examined and suggests important knowledge gaps in the extent of many damage-related socioeconomic impacts. Nation states spent the greatest proportion of their gross domestic products countering these costs, at least 1 order of magnitude higher than other locations. Most costs were borne by authorities and stakeholders, demonstrating the key role of governmental and nongovernmental bodies in addressing island invasions. Temporal trends revealed cost increases across all island types, potentially reflecting efforts to tackle invasive species at larger, more socially complex scales. Nevertheless, the already high total economic costs of island invasions substantiate the role of biosecurity in reducing and preventing invasive species arrivals to reduce strains on limited financial resources and avoid threats to sustainable development goals.Costos económicos de proteger a las islas de las especies invasoras Resumen Las invasiones biológicas representan una amenaza importante para los sistemas insulares, además de tener impactos pronunciados en el ambiente y en la economía. Los impactos ecológicos han recibido atención sustancial, mientras que los impactos socioeconómicos se encuentran pobremente sintetizados en las escalas temporales y espaciales. Usamos la base de datos InvaCost, el análisis más completo de los costos económicos de las especies invasoras, para evaluar los impactos económicos sobre las islas a nivel mundial. Analizamos los costos socioeconómicos en varios tipos de gastos y examinamos las tendencias temporales en las islas que difieren en su geografía política - islas estado-nación, territorios ultramarinos e islas de países continentales. En las islas han ocurrido gastos de más de $36 mil millones de dólares entre 1965 y 2020 debido a los impactos de las especies invasoras. Las islas estado-nación produjeron los mayores costos de manejo y el mayor total, mientras que las islas de los países continentales produjeron costos de una magnitud similar, ambas con gastos mucho más elevados que los de los territorios ultramarinos. Los costos de las pérdidas por daños fueron significativamente más bajas, aunque con patrones cualitativamente similares entre las diferentes geografías políticas. El predominio del gasto en el manejo difiere del patrón hallado en la mayoría de los países analizados y sugiere que hay vacíos importantes en el conocimiento del alcance de muchos de los impactos socioeconómicos relacionados con los daños. Las islas estado-nación gastaron la mayor proporción de su producto interno bruto en contrarrestar estos costos, al menos una orden de magnitud mayor que las otras localidades. La mayoría de los costos fueron asumidos por las autoridades y los accionistas, lo que demuestra el papel clave que tienen los organismos gubernamentales y no gubernamentales en cómo se atienden las invasiones insulares. Las tendencias temporales revelaron incrementos en el costo en todos los tipos de islas, lo que potencialmente refleja los esfuerzos por combatir a las especies invasoras a escalas más grandes y socialmente más complejas. Aun así, el elevado costo económico total de las invasiones insulares fundamenta la función que tiene la bioseguridad en la reducción y prevención de la llegada de especies invasoras para reducir presiones sobre los recursos financieros limitados y evitar amenazas para las metas de desarrollo sustentable.生物入侵是岛屿系统面临的主要威胁, 对环境和经济都产生了明显的影响。生态方面的影响已得到很多关注, 但社会经济方面的影响仍缺少时空尺度上的综合分析。本研究使用 InvaCost 数据库, 包含已发表的入侵物种经济成本最全面的评估数据, 来评估全球岛屿在生物入侵中面临的经济影响。我们分析了不同支出类型的社会经济成本, 并研究了不同政治地理的岛屿 (岛屿民族国家、海外领地和大陆国家的岛屿) 中社会经济成本随时间变化的趋势。结果显示, 从 1965 年到 2020 年, 岛屿由于入侵物种的影响产生的总成本 (包括破坏和管理) 超过 360 亿美元。民族国家的总成本和管理成本最高, 大陆国家的岛屿产生的成本规模相近, 都远远高于海外领地的成本。破坏导致的成本明显较低, 在不同政治地理的岛屿中有相似的情况。而管理支出占主导地位的情况则在我们研究的大多数国家中有所不同, 表明在许多与破坏有关的社会经济影响程度方面仍存在重要的知识空缺。民族国家用于这些成本的国内生产总值比例最高, 至少比其他地区高一个数量级。大多数费用由当局和利益相关者承担, 反映了政府和非政府机构在应对岛屿入侵问题中的关键作用。时间趋势分析表明, 所有类型的岛屿承担的成本都随时间推移而增加, 可能反映了在更大、更复杂的社会范围内应对生物入侵的努力。然而, 岛屿入侵问题的总经济成本已经很高, 这强调了应关注生物安全来减少和预防入侵物种的引入, 以减缓对有限财政资源的压力, 并避免对可持续发展目标的威胁。 【翻译: 胡怡思; 审校: 聂永刚】.

International audience; Invasive ants are amongst the most destructive and widespread invaders across the globe; they can strongly alter invaded ecosystems and are responsible for the loss of native ant species. Several studies have reported that invasive ants can also lead to substantial economic costs. In this study, we search, describe and analyse 1342 reported costs of invasive ants compiled in the InvaCost database. Economic costs, reported since 1930 for 12 ant species in 27 countries, totalled US dollars 51.93 billion, from which US dollars 10.95 billion were incurred, and US$ 40.98 billion were potential costs (i.e., expected or predicted costs). More than 80% of total costs were associated with only two species, Solenopsis invicta and Wasmannia auropunctata ; and two countries, the USA and Australia. Overall, damage costs amounted to 92% of the total cost, mainly impacting the agriculture, public and social welfare sectors. Management costs were primarily post-invasion management (US dollars 1.79 billion), with much lower amounts dedicated to prevention (US dollars 235.63 million). Besides the taxonomic bias, cost information was lacking for an average of 78% of the invaded countries. Moreover, even in countries where costs were reported, such information was available for only 56% of the invaded locations. Our synthesis suggests that the global costs of invasive ants are massive but largely biased towards developed economies, with a huge proportion of underreported costs, and thus most likely grossly underestimated. We advocate for more and improved cost reporting of invasive ants through better collaborations between managers, practitioners and researchers, a crucial basis for adequately informing future budgets and improving proactive management actions of invasive ants.; El coste económico mundial de las hormigas invasoras Las hormigas invasoras están entre las especies más destructivas y más ampliamente extendidas en todo el mundo. Pueden alterar fuertemente los ecosistemas y son responsables de la pérdida de numerosas especies de hormigas nativas en los ecosistemas invadidos. Muchos estudios han mostrado que las hormigas invasoras pueden producir costes económicos importantes. En este estudio, recopilamos, describimos y analizamos 1342 entradas de costes económicos de hormigas invasoras usando la base de datos InvaCost. Los costes económicos fueron reportados desde 1930, para 12 hormigas invasoras, en 27 países, alcanzando un total de 51.93 mil millones de dólares americanos de los cuales 10.95 mil millones fueron observados (costes reales) mientras que 40.98 mil millones de dólares americanos fueron costes potenciales (es decir, costes esperados, no observados). Más del 80% de los costes totales fueron causados por dos especies: Solenopsis invicta y Wasmannia auropunctata ; y en dos países: Estados Unidos y Australia. Los costes debidos a daños alcanzaron el 92% del total, afectando principalmente a los sectores agrícola y de bienestar social. Los costes de gestión se invirtieron en su mayoría en la gestión de post-invasión (1.79 mil millones de dólares), con montos mucho menores de inversión en prevención (235.63 millones de dólares). A nivel geográfico, falta información de reportes de costes económicos para aproximadamente un 78% de los países invadidos. Además, incluso en los países donde existían costes reportados, dicha información sólo estaba disponible para el 56% de los lugares invadidos. Nuestra síntesis sugiere que los costes globales de las hormigas invasoras son enormes pero en gran medida sesgados hacia las economías desarrolladas, con una gran proporción de costes sin reportar y por lo tanto gravemente subestimados. Exhortamos entonces, a un mayor y mejor reporte de los costes económicos de las hormigas invasoras a través de una mayor colaboración entre gestores, profesionales e investigadores; lo cual es la base crucial para informar adecuadamente presupuestos futuros y mejorar las actuaciones hacia una gestión proactiva de las hormigas invasoras.

Roadkill poses a significant threat to many wildlife species. To implement habitat management and conservation measures in protected areas, it is important to identify the factors related to roadki...

The prevalence of Toxoplasma gondii infection in free-ranging cats on Tokunoshima Island was assessed by testing 125 serum samples using anti-T. gondii IgG indirect enzyme-linked immunosorbent assay. The overall seropositivity rate was 47.2% (59/125). Seropositivity rates in cats with body weight >2.0 kg (57.4%) were significantly higher than in those with body weight ≤2.0 kg (12.5%, P

Understanding how invasive predators impact native species is essential for the development of effective control strategies, especially in insular environments where alternative non-native prey species exist. We examined seasonal and spatial shifts in diet of feral cat Felis silvestris catus focusing on the predation on native streaked shearwaters, Calonectris leucomelas, and introduced rats, Rattus rattus and R. norvegicus, which are alternative prey to shearwaters, on Mikura Island, Japan. Streaked shearwaters breed at low elevations on the island from spring to autumn, whereas rats inhabit the island throughout the year, which makes them an alternative prey when native shearwaters are absent. Fecal analysis revealed that feral cats dramatically shifted their diets from introduced rats in winter to streaked shearwaters in seabird-season in low elevation areas of the island, while cats preyed on rats throughout the year at high altitudes on the island. This finding suggests that feral cats selectively prey on shearwaters. This is probably because of their large body size and less cautious behavior, and because introduced rats sustain the cat population when shearwaters are absent. The number of streaked shearwaters killed was estimated to be 313 individuals per cat per year, which represents an indication of top-down effects of feral cats on streaked shearwaters. Further studies on the demographic parameters and interspecific interactions of the three species are required to enable effective cat management for the conservation of streaked shearwaters on this island.

Free-ranging cats Felis silvestris catus are harmful to endemic species, especially on islands. Effective management practices require an understanding of their habitat use and population source at the landscape level. We aimed to identify the source of the free-ranging cat population on Tokunoshima Island, Japan, which harbors a variety of endemic organisms as well as human settlements. Trapping data for the whole island were provided by local governments, and landscape factors (residential, agricultural, and woodlot areas and cattle barn density) affecting cat density were explored. An analysis of live-capture data indicated that the density (per 1 km2) of free-ranging cats was positively correlated with the densities of cattle barns and woodlot areas and negatively correlated with residential areas. An interview survey revealed that nearly half of the cattle barns feed free-ranging cats. The source habitat of free-ranging cats appears to be areas with a high density of cattle barns and a high percentage of woodlots in human-dominated landscapes. Feeding cats in cattle barns may strengthen the bottom-up process of population growth on the island. To reduce the impact of cats on endemic species on Tokunoshima Island, efforts to stop feeding cats in cattle barns are important. Reaching a consensus with stakeholders will require further studies of the ecological risks posed by free-ranging cats.

OBJECTIVESeveral environmental factors have been reported to correlate with incidence of spontaneous subarachnoid hemorrhage (SAH). However, because of different patient selection and study designs among these studies, meteorological factors that trigger the incidence of SAH in a short hazard period remain unknown. Among meteorological factors, daily temperature changes may disrupt and violate homeostasis and predispose to cerebrovascular circulatory disturbances and strokes. The authors aimed to investigate whether a decline in the temperature from the highest of the previous day to the lowest of the event day (temperature decline from the previous day [TDP]) triggers SAH in the prefecture-wide stroke database.METHODSAll 28 participating institutions with primary or comprehensive stroke centers located throughout Kochi Prefecture, Japan, were included in the study. Data collected between January 2012 and December 2016 were analyzed, and 715 consecutive SAH patients with a defined date of onset were enrolled. Meteorological data in this period were obtained from the Kochi Local Meteorological Observatory. A case-crossover study was performed to investigate association of TDP and other environmental factors with onset of SAH.RESULTSThe increasing TDP in 1°C on the day of the SAH event was associated with an increased incidence of SAH (OR 1.041, 95% CI 1.007–1.077) after adjustment for other environmental factors. According to the stratified analysis, a significant association between TDP and SAH was observed in women, patients < 65 years old, and patients with weekday onset. Among these factors, increasing TDP had a great impact on SAH onset in patients < 65 years old (p = 0.028, Mann-Whitney U-test).CONCLUSIONSTDP, temperature decline from the highest of the previous day to the lowest of the day, was correlated with the incidence of spontaneous SAH, particularly in younger patients < 65 years old.

To reduce the risk of zoonoses, it is necessary to understand the infection process, including the ecology of animals and vectors (i.e., the ‘One Health’ approach). In temperate climates, ticks are the major vectors of zoonoses, so factors determining their abundance, such as host mammal abundance and microhabitat conditions, should be clarified. Sika deer (Cervus nippon) are a major tick host and are rapidly expanding their distribution in Japan. We established 12 plots along a gradient of sika deer abundance in Tochigi Prefecture, Japan. We monitored the occurrence of mammal species with camera traps and sampled questing ticks on a monthly basis by flagging along three transects (center of a trail, forest edge, and forest interior) at each site from April to November 2018. The camera traps recorded 12 mammal species, predominantly sika deer. Five Haemaphysalis species and three Ixodes species were sampled. The numbers of ticks sampled were explained by the photographic frequency of sika deer, and partly by that of other mammal species, depending on tick species and their developmental stages. The numbers of sampled adult and nymphal ticks were the highest at the forest edge, where vegetation cover was greatest. Thus, vegetation management in tick habitats and the control of sika deer populations may reduce tick abundance.

Biological invasions represent a key threat to island ecosystems, with pronounced impacts across environments and economies. The ecological impacts have received substantial focus, but the economic costs have lacked synthesis at spatial and temporal scales. Here we utilise the InvaCost database, the most comprehensive global assessment of published economic costs of invasive species, to assess reported spend by cost types and socioeconomic sectors, and to examine temporal trends in spending, across islands that differ in their political geography - nation states, overseas territories or offshore islands of continental countries. We based this assessment on 1473 unique cost entries comprising 2914 annual costs totalling almost US$100 million in area-corrected costs between 1965-2020. We find that offshore islands of continental countries incur the greatest total and management costs. However, nation states incurred the greatest damage costs whilst substantially financing management actions, and spent an overall greater proportion of their GDP. In contrast, spending within overseas territories was significantly lower in all respects. The most impacted sector was authorities and stakeholders, demonstrating the key role of government in addressing island invasions. Temporal trends revealed continual increases in spending across all island types. This likely reflects ongoing introduction rates globally alongside an increased recognition of the importance of islands as biodiversity hotspots, and an appetite to tackle invasive species at larger and more socially complex scales. However, the high economic costs of invasions on islands substantiates the need to prevent them in order to avoid this dire threat to biodiversity and its burden on limited conservation resources.

Ticks are important vectors of several zoonoses such as severe fever with thrombocytopenia syndrome (SFTS), tick-borne encephalitis (TBE), and Japanese spotted fever (JSF), which have been increasing and expanding from west to east in Japan. Since there are no vaccines or treatments for SFTS and TBE and it is difficult to treat JSF in time, tick vector control is necessary. Given that a variety of tick species are involved in the transmission processes, host-animal control might be most effective.

Tick-borne diseases such as Severe Fever with Thrombocytopenia Syndrome (SFTS) are of concern as new issues in public health and conservation medicine. The SFTS virus especially is a fatal infection for feline animals. The emergence of STFS has been reported in China, Japan, South Korea, and Vietnam. Tsushima Islands, located between Kyushu Island of Japan and South Korea, are known as the habitat of the endangered Tsushima leopard cat (Prionailurus bengalensis euptilurus). The Ministry of the Environment of Japan reported the first case of SFTS infection in the free-ranging Tsushima leopard cat in 2022. Here, we report our investigation of the tick fauna on Tsushima Islands and its comparison with the abundance of Tsushima sika deer (Cervus nippon pulchellus). The flagging method was used at five collection sites on Tsushima islands in May 2022. We collected 131 ticks of three species, Haemaphysalis longicornis (127 individuals), H. formosensis (3) and Amblyomma testudinarium (1), among which H. longicornis was the dominant species. The abundance of H. longicornis increased with increased Deer Impact Score, which represents relative deer density based on five deer signs (bark stripping on Cryptomeria japonica or Chamaecyparis obtusa trees, browsing marks on the understory vegetation, deer fecal pellets, deer tracks, and deer trails). This study indicated that deer abundance may be an important factor in determining H. longicornis abundance. Notably, H. longicornis is known to serve as vector for several tick-borne pathogens, including SFTS virus. The relationships between ticks and wildlife hosts are expected to provide essential information from the perspectives of vector control, disease risk prediction, and conservation of rare species.

Fishing spiders, Dolomedes Latreille, 1804 (Pisauridae), are thought to be important predators in semi-aquatic ecosystems, but relatively few studies have investigated feeding ecology of Asian species. Here, we report on the diet of the Okinawan fishing spider, Dolomedes orion Tanikawa, 2003, the largest cursorial spider in Japan, based upon field observations on Amami Oshima Island in Kagoshima Prefecture and a literature review. A total of 13 predation events were observed in field surveys and 10 records were found in the literature. Together, these indicate the consumption of a broad range of food items from arthropods to vertebrates, e.g., insects, harvestman, conspecific spiders, crustaceans (freshwater crab and prawn), two species of endemic frogs (Rana ulma, Odorrana narina), and an Okinawa tree lizard (Japalura polygonata polygonata). Because this species has substantial energy demands for growth, large prey items such as crustaceans and vertebrates seem to be its primary food resources with 10 of 23 prey items [= 43%] belonging to these two large-sized prey groups.

Invasive species have caused severe impacts on biodiversity and human society. Although the estimation of environmental impacts caused by invasive species has increased in recent years, economic losses associated with biological invasions are only sporadically estimated in space and time. In this study, we synthesized the losses incurred by invasions in Asia, based on the most comprehensive database of economic costs of invasive species worldwide, including 560 cost records for 88 invasive species in 22 countries. We also assessed the differences in economic costs across taxonomic groups, geographical regions and impacted sectors, and further identified the major gaps of current knowledge in Asia. Reported economic costs of biological invasions were estimated between 1965 and 2017, and reached a total of US$ 432.6 billion (2017 value), with dramatic increases in 2000–2002 and in 2004. The highest costs were recorded for terrestrial ectotherms, for species estimated in South Asia, and for species estimated at the country level, and were related to more than one impacted sector. Two taxonomic groups with the highest reported costs were insects and mammals, and two countries with the highest costs were India and China. Non-English data covered all of 12 taxonomic groups, whereas English data only covered six groups, highlighting the importance of considering data from non-English sources to have a more comprehensive estimation of economic costs associated with biological invasions. However, we found that the estimation of economic costs was lacking for most Asian countries and for more than 96% of introduced species in Asia. Further, the estimation is heavily biased towards insects and mammals and is very limited concerning expenditures on invasion management. To optimize the allocation of limited resources, there is an important need to better and more widely study the economic costs of invasive alien species. In this way, improved cost reporting and more collaborations between scientists and stakeholders are needed across Asia.

Insular ecosystems reflect processes by which organisms have colonized from continents and are known as “experimental laboratory for evolution”. Islands have an order of magnitude more endemic spec...

It is important to unravel how invasive species impact native ecosystems in order to control them effectively. The presence of abundant exotic prey promotes population growth of invasive predators, thereby enhancing the predation pressure on native prey (hyper-predation). Not only the exotic prey but also feeding by humans is likely to cause “hyper-predation”. However, the contribution of artificial resources to this was underestimated in previous studies. Here, we combined fecal and stable isotope analyses to reveal short- and long-term food habits of free-ranging cats on Tokunoshima Island. Although 20.1% of the feral cat feces contained evidence of forest-living species, stable isotope analysis suggested that the cats were mostly dependent on artificial resources. In addition, a general linear model analysis showed that their diet was strongly correlated with landscape variables. These results indicate that the invasive free-ranging cats are aided by anthropogenic feeding, and they move from the human habituated area to natural areas with high biodiversity. These findings suggest the possibility of human feeding indirectly accelerates the effect of cat predation, and call for a further study on their demography. Cat management mainly involves trapping, but our findings show that educating local residents to stop feeding free-ranging cats and keeping pet cats indoors are also important.

Although forest roads are known to have negative effects on wildlife, frogs often are observed sitting along small forest roads, possibly using them as hunting sites. To determine if forest roads can be attractive hunting sites for frogs, biomass and composition of potential prey on roads and in adjacent forest were compared. Sticky sheet traps were placed on the roads or 10 m inside adjacent forest overnight at 22 sites in subtropical secondary forest on Amami Island, Japan. Trapped invertebrates were categorized into 10 taxonomic groups, and their dry weights were estimated from body size using an allometric equation for each group. There was no difference in biomass or composition between on-road and in-forest trapped invertebrates. This work suggested that forest roads are not necessarily better foraging areas for frogs than adjacent forest in terms of the quantity and composition of prey.

This paper presents a highly efficient aggregation query processing method for large-scale multidimensional data. Recent developments in network technologies have led to the generation of a large amount of multidimensional data, such as sensor data. Aggregation queries play an important role in analyzing such data. Although relational databases (RDBs) support efficient aggregation queries with indexes that enable faster query processing, increasing data size may lead to bottlenecks. On the other hand, the use of a distributed key-value store (D-KVS) is key to obtaining scale-out performance for data insertion throughput. However, querying multidimensional data sometimes requires a full data scan owing to its insufficient support for indexes. The proposed method combines an RDB and D-KVS to use their advantages complementarily. In addition, a novel technique is presented wherein data are divided into several subsets called grids, and the aggregated values for each grid are precomputed. This technique improves query processing performance by reducing the amount of scanned data. We evaluated the efficiency of the proposed method by comparing its performance with current state-of-the-art methods and showed that the proposed method performs better than the current ones in terms of query and insertion.

Character displacement is phenotypic divergence driven by competition (ecological character displacement) or reproductive interference (reproductive character displacement). Although previous studies have examined these phenomena separately, recent evidence suggests that reproductive interference can drive both reproductive and ecological character displacement, in that certain traits are related to both competition and reproduction. Thus, to evaluate the effect of competition, the effect of reproductive interference must be excluded. Here, we analysed ecological character displacement between non-congeneric frogs, which show little reproductive interference. Odorrana amamiensis inhabits the Amami and Tokunoshima Islands, Japan, whereas its non-congeneric competitor Babina subaspera inhabits the Amami Island. We tested three of the Schluter (2000) criteria for ecological character displacement: phenotypic changes in O. amamiensis between the two islands, phenotypic change related to prey preference, prey availability between the two islands. We demonstrated that the three criteria in Schluter (2000) were likely to be satisfied, indicating the occurrence of ecological character displacement in non-congeners without reproductive interference. Thus, we conclude that competition is potentially the main driver of this phenotypic divergence, and that non-congeners may be a suitable model for evaluating ecological character displacement in a variety of organisms, as the influence of reproductive interference can be excluded.

Wildlife populations on Amami Island, Japan, have been affected by forest clear-felling and the introduction of alien species, in particular the mongoose Herpestes auropunctatus. We used monitoring data collected over 24 years to track changes in the population sizes of five species of mammals and 20 species of birds. We assigned species to the following groups: indigenous, rare, insectivorous, negatively affected by forest clear-cutting, and negatively affected by mongoose invasion. We examined trends in each group at four time points between 1985 and 2010 using two methods: species abundance estimates and the Living Planet Index. We then assessed the usefulness of these methods as tools for conservation planning. Inspecting species individually we identified four main patterns of abundance change: (a) an increase from the first to the last census period, (b) an increase in all periods except 2009–2010, (c) a decrease from 1985–1986 to 2001–2002 but an increase in 2009–2010, and (d) a decrease in all census periods. We observed certain relationships between these patterns and the species groups assigned as above. According to the Living Planet Index the group negatively affected by forest clear-cutting did not show significant recovery and the groups of rare species and species negatively affected by mongoose recovered to c. 40% of the original level after a sharp decline during 1985–2002. The Living Planet Index is a more useful tool for assessing the urgency of particular conservation needs, although limited information on species abundance reduces its representativeness for some groups.

For maintaining social and financial support for eradication programs of invasive species, quantitative assessment of recovery of native species or ecosystems is important because it provides a measurable parameter of success. However, setting a concrete goal for recovery is often difficult owing to lack of information prior to the introduction of invaders. Here, we present a novel approach to evaluate the achievement level of invasive predator management based on the carrying capacity of endangered species estimated using long-term monitoring data. In Amami-Oshima Island, Japan, where the eradication project of introduced small Indian mongoose is ongoing since 2000, we surveyed the population densities of four endangered species threatened by the mongoose (Amami rabbit, the Otton frog, Amami tip-nosed frog, and Amami Ishikawa's frog) at four time points ranging from 2003 to 2011. We estimated the carrying capacities of these species using the logistic growth model combined with the effects of mongoose predation and environmental heterogeneity. All species showed clear tendencies toward increasing their density in line with decreased mongoose density, and they exhibited density-dependent population growth. The estimated carrying capacities of three endangered species had small confidence intervals enough to measure recovery levels by the mongoose management. The population density of each endangered species has recovered to the level of the carrying capacity at about 20–40% of all sites, whereas no individuals were observed at more than 25% of all sites. We propose that the present approach involving appropriate monitoring data of native organism populations will be widely applicable to various eradication projects and provide unambiguous goals for management of invasive species.

The small Indian mongoose Herpestes auropunctatus, which was recently determined to be a separate species from the Javan mongoose H. javanicus, is one of the most notorious invasive predators known. A population of Herpestes sp. was recently reported at Kagoshima prefecture on Kyushu Island, one of the main Japanese islands. Surprisingly, the trapping actions and information from residents after this report suggest that this Herpestes sp. population has been established in this area for at least 30 years. In this study, based on mitochondrial DNA sequences, we identified seven recently obtained Herpestes sp. individuals from this area as H. auropunctatus, confirming that an additional mongoose population has been established on Kyushu Island. Confirmation of the spatial distribution of the mongoose and surveillance systems in surrounding areas are urgently needed to prevent further expansion of this mongoose’s distribution. It also highlights the large gap between the accepted scientific knowledge relating to biosecurity against biological invasion and local knowledge on the ground, even when the introduced species is notorious and relatively conspicuous. Recent progressions of invasibility studies would greatly contribute to the prioritization of allocating adequate resources to areas with high invasion risks.

Quantifying the food composition of invasive predatory mammals by biomass ingested could be valuable for assessing their top–down effects, although it has rarely been estimated. Using gut content analyses is difficult because there is no direct way to estimate the ingested biomass of large prey items, which provide invasive predatory mammals with more than a single–meal. We examined the single–meal maximum ingestion of the small Indian mongoose in relation to its body weight by feeding trials. The result showed the relationship of Y = 0.260X 0.807, where Y is the single meal maximum ingestion (g) and X is the body weight of the mongoose (g)). The average single meal maximum ingestion of the mongoose with a weight of 500.0 ± 3.6 g (mean ± SE, n = 1961) was estimated to be 38.9 ± 0.23 g. Our findings may help create a direct linkage between the food analyses and impact assessments of invasive predatory mammals.

A temporally structured model that enables simulation of the development of the west Japan type yellow-spotted longicorn beetle, Psacothea hilaris (Pascoe), at different locations was developed. Life history parameter values incorporated into the model were estimated by laboratory rearing experiments. To validate the present model, the development of eggs laid monthly from June 1 through November 1 was simulated under dynamic temperature and photoperiod conditions at Ayabe City. The individuals laid on June 1 did not enter diapause but emerged in early August of the same year. On the other hand, about 2/3 of the individuals laid on July 1, and all those laid on August 1 and September 1 entered diapause (or quiescence), and started to emerge in late May of the following year. Individuals laid on October 1 and November 1 overwintered as young larvae (1st–3rd stadia) and eggs, respectively, and the majority of these emerged in late July–early August. Interestingly, the remaining individuals entered diapause in the 2nd year and emerged in June of the 3rd year. Analyses of these simulation results suggested that concentrated emergence of P. hilaris can occur twice in one year (in late May–early June and in late July–early August) at Ayabe, and this is fairly concordant with known adult prevalence at this location considering the long life-span of adults. It was also suggested that although P. hilaris at Ayabe has basically a univoltine life cycle with a facultative diapause, varying proportions of the population appear to have a bivoltine life cycle or a semivoltine life cycle depending on the meteorological conditions of that year. The life cycle of P. hilaris is suggested to be very flexible and adaptive to environmental fluctuations.

We examined the distribution patterns of native animals on Amami-Oshima Island, southern Japan, along a historical gradient of mongoose establishment and estimated the effects of mongoose on the native fauna. To assess the relative abundance of various ground-dwelling animals, we used the following four methods; sensor cameras for exotic mammals, nighttime driving census for nocturnal native vertebrates, line census for ground-dwelling lizards, and adhesive traps for arthropods. The results indicated that seven species with larger body size, including mammals, birds, reptiles, and amphibians, were rarely observed in mongoose-infested area. By contrast, medium-sized animals showed neutral relationships with mongoose establishment. Interestingly, the densities of smaller-sized animals were higher in mongoose-infested area. It could be interpreted that smaller species have increased in abundance through top-down cascades, i.e., decreases in native predators such as frogs and lizards caused by the mongoose have resulted in increases in the abundance of smaller animals. Predation pressures by mongoose and native predators may be canceled out for medium-sized animals, causing neutral responses to mongoose by these animals. This study appears to be the first example that shows the influence of mongoose on a wide variety of native animals. In addition, our findings indicate the importance of considering the food web structure of a recipient ecosystem and contribute to the prediction and assessment of ecological risks caused not only by mongoose, but also by other invasive top predators.