Is the increased vigour of invasive weeds explained by a trade-off between growth and herbivore resistance?

Blossey and Nötzold (1995) recently hypothesised that the increased vigour of certain invasive plant species has been at the expense of defences against natural enemies. A prediction of their evolution of increased competitive ability (EICA) hypothesis is that invasive genotypes are relatively poorly defended. We tested this prediction with herbivore bioassays and with direct quantification of plant secondary metabolites comparing non-indigenous genotypes of Lythrum salicaria L. (purple loosestrife) with indigenous forms. The herbivore bioassays revealed no significant intra-specific variation in herbivore resistance between indigenous and non-indigenous hosts. The phenolic content of L. salicaria leaves was significantly higher in indigenous genotypes, as predicted by the EICA hypothesis. The average phenolic content of leaves (regardless of their origin) was, however, low, implying that the role of plant phenolics in purple loosestrife anti-herbivore defence is probably limited. It is suggested that the EICA hypothesis, as tested in the current study, does not explain the increased vigour of L. salicaria in non-indigenous habitats.     

Interpersonal contact and attitudes towards indigenous peoples in Canada's prairie cities

Research finds that non-indigenous peoples often hold negative racial attitudes towards indigenous peoples. Contact theory suggests that interpersonal contact can positively influence majority group members’ attitudes regarding minority group members, raising the question of whether indigenous population growth in cities will alter non-indigenous peoples’ attitudes. Using original 2014 survey data, this paper examines the relationship between interpersonal contact and racial attitudes in Canadian prairie cities. The analysis finds that while personal ties to aboriginal peoples are correlated with lower new and old-fashioned racism scores, general contact with aboriginal peoples only correlates with old-fashioned racism scores. As such, growing urban indigenous populations – and thus increased aboriginal-non-aboriginal general contact – alone should not be expected to result in positive racial attitudes. This research advances understanding of contact theory by considering how education interacts with interpersonal contact, and informs on-going dialogue about current racial relations between non-indigenous and indigenous peoples in Canadian prairie cities.     

The invasive shrub Buddleja davidii performs better in its introduced range

It is commonly assumed that invasive plants grow more vigorously in their introduced than in their native range, which is then attributed to release from natural enemies or to microevolutionary changes, or both. However, few studies have tested this assumption by comparing the performance of invasive species in their native vs. introduced ranges. Here, we studied abundance, growth, reproduction, and herbivory in 10 native Chinese and 10 invasive German populations of the invasive shrub Buddleja davidii (Scrophulariaceae; butterfly bush). We found strong evidence for increased plant vigour in the introduced range: plants in invasive populations were significantly taller and had thicker stems, larger inflorescences, and heavier seeds than plants in native populations. These differences in plant performance could not be explained by a more benign climate in the introduced range. Since leaf herbivory was substantially reduced in invasive populations, our data rather suggest that escape from natural enemies, associated with increased plant growth and reproduction, contributes to the invasion success of B. davidii in Central Europe.     

Phenotypic and genetic differentiation between native and introduced plant populations

Plant invasions often involve rapid evolutionary change. Founder effects, hybridization, and adaptation to novel environments cause genetic differentiation between native and introduced populations and may contribute to the success of invaders. An influential idea in this context has been the Evolution of Increased Competitive Ability (EICA) hypothesis. It proposes that after enemy release plants rapidly evolve to be less defended but more competitive, thereby increasing plant vigour in introduced populations. To detect evolutionary change in invaders, comparative studies of native versus introduced populations are needed. Here, we review the current empirical evidence from: (1) comparisons of phenotypic variation in natural populations; (2) comparisons of molecular variation with neutral genetic markers; (3) comparisons of quantitative genetic variation in a common environment; and (4) comparisons of phenotypic plasticity across different environments. Field data suggest that increased vigour and reduced herbivory are common in introduced plant populations. In molecular studies, the genetic diversity of introduced populations was not consistently different from that of native populations. Multiple introductions of invasive plants appear to be the rule rather than the exception. In tests of the EICA hypothesis in a common environment, several found increased growth or decreased resistance in introduced populations. However, few provided a full test of the EICA hypothesis by addressing growth and defence in the same species. Overall, there is reasonable empirical evidence to suggest that genetic differentiation through rapid evolutionary change is important in plant invasions. We discuss conceptual and methodological issues associated with cross-continental comparisons and make recommendations for future research. When testing for EICA, greater emphasis should be put on competitive ability and plant tolerance. Moreover, it is important to address evolutionary change in characteristics other than defence and growth that could play a role in plant invasions.     

The interaction between lodging and plant population in combining peas

The effects of preventing lodging in three varieties of combining peas with contrasting standing ability were studied over a range of plant populations and in two growing seasons. Maximal yield losses resulted when lodging occurred prior to the end of the flowering period. The likelihood of this event occurring was increased by high populations and was maximised when such populations were used in conjunction with conditions suitable for vigorous plant growth. In such seasons, optimum plant populations (30 plants m^-2) were seen to be very much below those currently recommended. When conditions were less favourable to plant growth, lodging tended to occur after flowering had ceased. Little yield loss due to population effects were then recorded. Under such conditions, yields were maximised by high plant populations. Under all growing conditions, little yield loss due to interplant competition was noted with increasing plant populations. It was concluded from these results that if combining pea production is to be successfully expanded out of traditional production areas, plant population recommendations should be lowered to compensate for increased plant vigour.     

Ethnic heterogamy and the risk of partner violence in Mexico

A common stereotype holds that in Mexico male violence toward women is common among indigenous peoples and reflects cultural norms that sanction a male's domination of his female partner. We employ a recent Mexican survey to examine the relative risk of violence against women as a function of the couple's ethnic homogamy. Among couples in which both partners are either non-indigenous or indigenous the female's risk of partner violence is similar. Among heterogamous couples non-indigenous females in relationships in which the male is indigenous are at elevated risk of violence, while indigenous women in relationships with non-indigenous males are at a lower risk of violence. The stresses associated with heterogamy appear to be more salient in determining a woman's risk of violence than ethnicity per se. The implications for future research and the need to deal with the issue of ethnic homogamy in culturally heterogeneous populations are discussed.     

Enemy release does not increase performance of <Emphasis Type="Italic">Cirsium</Emphasis> <Emphasis Type="Italic">arvense</Emphasis> in New Zealand

Cirsium arvense (L.) Scop. (Californian, Canada, or creeping thistle) is an exotic perennial herb indigenous to Eurasia that successfully established in New Zealand (NZ) approximately 130 years ago. Presently, C. arvense is considered one of the worst invasive weeds in NZ arable and pastoral productions systems. A mechanism commonly invoked to explain the apparent increased vigour of introduced weeds is release from natural enemies. The enemy-release hypothesis (ERH) predicts that plants in an introduced range should experience reduced herbivory, particularly from specialists, and that release from this natural enemy pressure facilitates increased plant performance in the introduced range. In 2007, surveys were carried out in 13 populations in NZ (7 in the North Island and 6 in the South Island) and in 12 populations in central Europe to quantify and compare growth characteristics of C. arvense in its native versus introduced range. Altitude and mean annual precipitation for each population were used as covariates in an attempt to explain differences or similarities in plant traits among ranges. All plant traits varied significantly among populations within a range. Shoot dry weight was greater in the South Island compared to Europe, which is in line with the prediction of increased plant performance in the introduced range; however, this was explained by environmental conditions. Contrary to expectations, the North Island was not different from Europe for all plant traits measured, and after adjustment for covariates showed decreased shoot density and dry weight compared to the native range. Therefore, environmental factors appear to be more favourable for growth of C. arvense in both the North and South Islands. In accordance with the ERH, there was significantly greater endophagous herbivory in the capitula and stems of shoots in Europe compared to both NZ ranges. In NZ, capitulum attack from Rhinocyllus conicus was found only in the North Island, and no stem-mining attack was found anywhere in NZ. Thus, although C. arvense experiences significantly reduced natural enemy pressure in both the North and South Islands of NZ there is no evidence that it benefits from this enemy release.     

The non-indigenous freshwater fishes of Flanders (Belgium): review, status and trends over the last decade

Fourteen non-indigenous fish species have been successfully introduced to the wild within the territory of Flanders; nine are considered naturalized. Most of the introductions occurred prior to 1950, with six species introduced since then. This paper reviews the available, hitherto scattered, information (including 'grey literature') on these 14 non-indigenous fish species introductions, and evaluates a decade of data from fisheries surveys to assess the recent development of these non-indigenous populations. Gibel carp Carassius gibelio and topmouth gudgeon Pseudorasbora parva are the most widespread of the non-indigenous species in Flemish waters, and both continue to expand their ranges. A reduction in range has been observed in brown bullhead Ameiurus nebulosus only. A case is presented for not including European catfish Silurus glanis , sunbleak Leucaspius delineatus and European bullhead Cottus gobio on the list of non-indigenous freshwater fishes in Flanders. Also discussed are non-indigenous fish species that are likely to colonize Flanders inland waters in the near future.     

Effect of Inoculation with Non-indigenous and Indigenous Rhizobacteria of Erzurum (Turkey) Origin on Growth and Yield of Spring Barley

Two experiments were performed to examine the effects of inoculation of barley cv. Tokak 157/37 with indigenous and non-indigenous bacterial strains. A greenhouse experiment was carried out with 75 strains isolated from Erzurum Plain and Pasinler Plain soils of Turkey, and the 6 non-indigenous strains. The 41 strains had significant positive effects on tiller number per plant, 8 strains on plant height, one strain on dry matter yield, and 24 strains on plant protein concentration. In the second experiment, the response of barley to 20 treatments (9 indigenous strains, 6 non-indigenous strains, 4 levels of N, and a control) was investigated in Erzurum Agricultural Experiment field in 2000 and 2001. Inoculation with certain indigenous and non-indigenous strains clearly benefited growth and increased the yield of field grown barley. On average of years, inoculation with Strain No. 19, Strain No. 39, Strain No. 73, Strain No. 82, BA-7, BA-142 and M-13 increased total biomass by 29.4–15.1%, grain yield by 26.6–17.7%, and total N-yield by 32.7–20.6%, as compared to the control. Indigenous Strain No. 19 was superior to all other treatments in terms of grain yield and N-yields. The higher efficacy of combining Strain No. 19 and Tokak 157/37 indicates the possibility of improved associations using olden and common cultivar and indigenous bacteria. In conclusion, Strain No. 19 seems to be suitable inoculant for barley cultivation in areas such as in Erzurum conditions.     

The Natural Host Range of Steinernema and Heterorhabditis spp. and Their Impact on Insect Populations

The natural host range of entomopathogenic nematodes of the genera Steinernema and Heterorhabditis can be defined as the range of insects which indigenous nematode populations use for propagation. Information on the natural host range is rare. However, based on records of insects found to be naturally infected with nematodes, some conclusions regarding the natural host range of some Steinernema spp. and Heterorhabditis spp. are presented. Reports of indigenous nematode populations impacting on insect populations can be divided between relatively balanced, long-lasting nematode-host associations and unbalanced, short-lasting epizootics. Examples of the augmentation and inoculative introduction of nematodes in agriculture and forestry ecosystems are presented. Based on current knowledge, nematode reproduction strategies are discussed and indications of the risk involved in the release of non-indigenous nematodes are given.     

Palatability to a generalist herbivore,defence and growth of invasive and native <Emphasis Type="Italic">Senecio</Emphasis> species: testing the evolution of increased competitive ability hypothesis

This paper tests the prediction that introduced plants may become successful invaders because they experience evolutionary changes in growth and defence in their new range [evolution of increased competitive ability hypothesis (EICA)]. Interspecific and intraspecific binary feeding choices were offered to the snail Helix aspersa. The choices were between: (1) plants of the invasive Senecio inaequidens and Senecio pterophorus derived from populations in the introduced range (Europe) and plants of three indigenous species (Senecio jacobea, Senecio vulgaris and Senecio malacitanus) from populations in Europe; (2) plants of the invasive S. inaequidens and S. pterophorus from populations in the introduced range (Europe) and from populations in the native range (South Africa). We did not find a clear pattern of preference for indigenous or alien species of Senecio. However, we found that European invasive populations of S. inaequidens and S. pterophorus were less palatable than South African native populations. Moreover, in contrast to the predictions of the EICA hypothesis, the invasive genotypes of both species also showed a higher total concentration of pyrrolizidine alkaloids, and in the case of S. inaequidens we also found higher growth than in native genotypes. Our results are discussed with respect to the refinement of the EICA hypothesis that takes into account the difference between specialist and generalist herbivores and between qualitative and quantitative defences. We conclude that invasive populations of S. inaequidens and S. pterophorus are less palatable than native populations, suggesting that genetic differentiation associated with founding may occur and contribute to the plants’ invasion success by selecting the best-defended genotypes in the introduced range.     

Feeding ecology of indigenous and non-indigenous fish species within the family Sphyraenidae

The feeding ecology of two common indigenous (Sphyraena viridensis and Sphyraena sphyraena) and one abundant non-indigenous sphyraenid species, Sphyraena chrysotaenia, of Indo-Pacific Ocean origin, was investigated in an area of the eastern Mediterranean Sea. The stomach contents of 738 individuals of varying size, collected during the period December 2008 to August 2009, were examined. The dietary analyses revealed that all three species were specialized piscivores with a diet consisting of >90% fish, both by number and mass. Concurrent sampling of the fish assemblage made it possible to calculate selectivity as well as diet breadth and overlap of these strict piscivores. Even though several prey species were found in the stomachs of the three predators examined, selectivity towards Atherina boyeri was highly significant. For all species examined, >70% of the diet by mass was made up by three indigenous species of commercial value: Spicara smaris, Boops boops and A. boyeri. Diet breadth and size of prey increased with increasing body size for all predators. With increased body size, the diet overlap between indigenous and non-indigenous species decreased. This could be attributed to increased diet breadth and the specific life-history characteristics of indigenous species developing into larger individuals. During winter, the condition factor of the non-indigenous species was significantly lower than that of the indigenous, indicating that winter conditions in the Mediterranean Sea may limit its further expansion north and westward. With this study, the gap in knowledge of the feeding preferences of the most abundant piscivorous species found in coastal areas of the study region is filled. Additionally, the results indicate that non-indigenous species familial affiliation to indigenous ones does not facilitate invasion success.     

Comparison of defence and performance traits between one widespread clone and native populations in a major invasive plant species

Aim

The success of invasive species in their introduced range is often assumed to result from evolutionary changes in defence and growth traits, or as a response to more favourable conditions. The latter is assumed particularly for species exhibiting low, or even no, sexual reproduction in the introduced range.

Location and Methods

Here, we compared Japanese (native range) and French (introduced range) populations of Fallopia japonica under common growth conditions in a glasshouse. We measured height, aboveground and belowground mass, stem stiffness, leaf toughness and secondary metabolites found in hydroalcoholic extracts of rhizomes of F. japonica, as well as the competitive response of Rubus caesius (a co‐occurring native species in the invaded range) in the presence of F. japonica from both ranges.

Results

Aboveground biomass, height, stem stiffness and composition of secondary metabolites were not significantly different between the two ranges, showing that increased aboveground vigour observed in situ in France is probably the result of a plastic response following the release of abiotic or biotic constraints from the native range. On the other hand, belowground mass, effect on R. caesius, and leaf toughness were all higher in French populations, suggesting increases in competitive ability and defence mechanisms. These differences between France and Japan may be explained either by post‐introduction evolution or by the introduction in Europe, in nineteenth century, of an exceptionally vigorous clone (pre‐adaptation).

Main conclusions

Our results provide evidence that the high vigour of this major invasive species in its introduced range is probably due to both a response to more favourable conditions and rapid evolution.

     

Integration of non-indigenous species within the interspecific abundance–occupancy relationship

There is a broad consensus that habitat disturbance and introduction of non-indigenous species may dramatically modify community structure, particularly in insular ecosystems. However, it is less clear whether emergent macroecological patterns are similarly affected. The positive interspecific abundance–occupancy relationship (IAOR) is one of the most pervasive macroecological patterns, yet has rarely been analyzed for oceanic island assemblages. We use an extensive dataset for arthropods from six islands within the Azorean archipelago to test: (1) whether indigenous and non-indigenous species are distributed differently within the IAOR; and (2) to the extent that they are, can differences can be attributed to two indices of disturbance. We implemented modeling averaged methods using five of the most common IAOR models to derive an averaged IAOR fit for each island. After testing if species colonization status (indigenous versus non-indigenous) may explain the residuals of the IAOR, we identified true negative and positive outliers and tested the effect of colonization status on the likelihood of a species being a positive or negative outlier. We found that the indigenous and non-indigenous species are randomly distributed on both sides of the overall IAOR. Only for Flores Island, were non-indigenous species more aggregated than indigenous species. We were unable to detect a meaningful relationship between deviation from the IAOR and disturbance, despite the undoubted impact of both severe habitat loss and non-indigenous species on these oceanic islands. Our results show that the non-indigenous species have been integrated alongside indigenous species in the contemporary Azorean arthropod communities such that they are mostly undetectable by the study of the IAOR.     

Biotic resistance to plant invasion in grassland: Does seed predation increase with resident plant diversity?

Seed predation impacts heavily on plant populations and community composition in grasslands. In particular, generalist seed predators may contribute to biotic resistance, i.e. the ability of resident species in a community to reduce the success of non-indigenous plant invaders. However, little is known of predators’ preferences for seeds of indigenous or non-indigenous plant species or how seed predation varies across communities. We hypothesize that seed predation does not differ between indigenous and non-indigenous plant species and that seed predation is positively related to plant species diversity in the resident community. The seed removal of 36 indigenous and non-indigenous grassland species in seven extensively or intensively managed hay meadows across Switzerland covering a species-richness gradient of 18–50 plant species per unit area (c. 2 m²) was studied. In mid-summer 2011, c. 24,000 seeds were exposed to predators in Petri dishes filled with sterilized soil, and the proportions of seeds removed were determined after three days’ exposure. These proportions varied among species (9.2–62.5%) and hay meadows (17.8–48.6%). Seed removal was not related to seed size. Moreover, it did not differ between indigenous and non-indigenous species, suggesting that mainly generalist seed predators were active. However, seed predation was positively related to plant species richness across a gradient in the range of 18–38 species per unit area, representing common hay meadows in Switzerland. Our results suggest that generalist post-dispersal seed predation contributes to biotic resistance and may act as a filter to plant invasion by reducing the propagule pressure of non-local plant species.     

Cultivation Fosters Plant Naturalization by Reducing Environmental Stochasticity

A large fraction of the immigrant (or founder) populations of terrestrial plants are small (< 10⁴) and are acutely sensitive to environmental stochasticity. As a result, they undergo radical size fluctuations during a prolonged lag phase that almost always result in their extirpation. Naturalizations are those rare examples in which an immigrant population increases above a threshold size such that the consequences of environmental stochasticity are markedly lower. The likelihood that a non-indigenous population will reach this threshold size would be enhanced substantially through either deliberate or inadvertent cultivation. Cultivation (e.g. protection from predators, parasites, drought, frost) shields small immigrant populations from the extreme expressions of environmental stochasticity. In addition, cultivation can preserve through seed storage a residual non-indigenous population from which new populations can be established. As disseminules are spread locally, and even regionally, immigrant populations sample a wide variety of micro-habitats, thus increasing the likelihood that some plants will survive even without cultivation. Origins of naturalized floras in Australia and the US reveal a strong circumstantial link between cultivation and subsequent naturalization: the single largest group of naturalized species was deliberately introduced as either crops, forage spp., or ornamentals. Another group was introduced inadvertently as contaminants in crop seeds. This correspondence between cultivation and subsequent naturalization provides a common demographic explanation for non-indigenous plant persistence that largely transcends species’ attributes and the commonly ascribed features of communities that are vulnerable to the entry of non-indigenous plants. Humans have played a more profound role in fostering plant naturalizations than by acting simply as plant dispersers; their post-immigration cultivation fosters much naturalization. This revised version was published online in July 2006 with corrections to the Cover Date.     

Evidence of multiple introductions and genetic admixture of the Asian brush-clawed shore crab <Emphasis Type="Italic">Hemigrapsus takanoi</Emphasis> (Decapoda: Brachyura: Varunidae) along the Northern European coast

The Asian brush-clawed shore crab Hemigrapsus takanoi is a non-indigenous species along the Northern European coast. Although the history of range expansion of European H. takanoi has been well-documented, little is known about the genetic compositions of either the introduced European populations or the native Asian ones. We therefore collected H. takanoi broadly from their native Asian sites and introduced European ranges, and genotyped them by sequencing the mitochondrial 16S RNA gene and by analyzing nuclear microsatellite loci. Our results revealed that the H. takanoi Bay of Seine (France) populations consisted of a genetic admixture between populations in Japan and those in the Yellow Sea region. These French populations should be carefully monitored in the future, since the genetic admixture of multiple source populations may accelerate range expansion in non-indigenous organisms. Our results also suggested that shipping lines from East Asia were more probable vectors than historical juvenile oyster transportations from Japan for the foundation of present European H. takanoi populations. Interestingly, gene flow between populations in Japan and those in the Yellow Sea region (i.e., domestic invasion) was not observed despite the higher potential for artificial translocations via shipping lines in the native Asian range compared with those from Asia to Europe. The lack of domestic invasions implied that intra-specific priority effects of the resident H. takanoi populations played an important role in preventing the successful colonization of artificially-transferred individuals.     

Non-indigenous grasses impede woody succession

With the proliferation of old fields and the decline of native grasslands in North America, non-indigenous grasses, which tend to colonize and dominate North American old fields, have become progressively more abundant. These new grasses can differ from native grasses in a number of ways, including root and shoot morphology (e.g., density of root mat, height of shoots), growth phenology (e.g., cool season vs. warm season growth), and plant–soil–water relations due to differences in photosynthetic physiology (C₃ vs. C₄). Woody plants have been slow to colonize some old fields in the prairie-forest border area of North America and it is hypothesized that non-indigenous grasses may be contributing to the poor establishment success of woody plants in this region, possibly through more intense competition for resources. To test this hypothesis, a multi-factorial field experiment was conducted in which water, nitrogen, and grass functional group (non-indigenous C₃ and native C₄ species) were manipulated in a study of survival of oak seedlings. The grass type variously affected some of the different growth measurements, however, the effects of grass type on seedling growth were small compared to the effects on seedling survival. The results showed that when grown under dry conditions, seedlings growing in non-indigenous grasses experienced up to a 50% reduction in survival compared to those growing in native grasses under the same conditions. Analyses of root and shoot competition showed that the cause for the reduced survival in the non-indigenous grasses was due primarily to underground processes. The findings confirmed our initial hypothesis that non-indigenous grasses are likely contributing to the poor establishment success of woody plants in these old fields. However, the explanation for the reduced oak seedling survival in non-indigenous grasses does not appear to be due to reduced resource availability since soil water levels did not differ between non-indigenous and native grass plots and other resource levels measured (light, NO₃, and NH₄) were higher in non-indigenous grass plots under dry conditions. An alternative explanation is that the non-indigenous grasses modify the soil environment in ways that, under dry conditions, are deleterious to emerging oak seedlings. Since current climate projections for the upper Midwest are for hotter and drier summers, the results suggest that the resistance of these old fields to oak encroachment will likely increase in the future.     

Non-indigenous brook trout and the demise of Pacific salmon: a forgotten threat?

Non-indigenous species may be the most severe environmental threat the world now faces. Fishes, in particular, have been intentionally introduced worldwide and have commonly caused the local extinction of native fish. Despite their importance, the impact of introduced fishes on threatened populations of Pacific salmon has never been systemically examined. Here, we take advantage of several unique datasets from the Columbia River Basin to address the impact of non-indigenous brook trout, Salvelinus fontinalis, on threatened spring/summer-run chinook salmon, Oncorhynchus tshawytscha. More than 41 000 juvenile chinook were individually marked, and their survival in streams without brook trout was nearly double the survival in streams with brook trout. Furthermore, when brook trout were absent, habitat quality was positively associated with chinook survival, but when brook trout were present no relationship between chinook survival and habitat quality was evident. The difference in juvenile chinook survival between sites with, and without, brook trout would increase population growth rate (lambda) by ca. 2.5%. This increase in lambda would be sufficient to reverse the negative population growth observed in many chinook populations. Because many of the populations we investigated occur in wilderness areas, their habitat has been considered pristine; however, our results emphasize that non-indigenous species are present and may have a dramatic impact, even in remote regions that otherwise appear pristine.     

Wildmeat or Bushmeat? Subsistence Hunting and Commercial Harvesting in Papua (West New Guinea), Indonesia

It is well known that wild game provides a significant proportion of the dietary protein of the indigenous people of the eastern half of New Guinea (PNG), but almost nothing is known of its importance in the western half (the Indonesian province of Papua or Irian Jaya). We quantified hunting effort, harvest rates and wild meat consumption and sale in the Jayapura region of north-east Papua through interviews with 147 hunters from 21 villages and meal surveys in 93 households. Ten species of mammals, seven species of birds and at least two species of reptiles were harvested in our study area, but the introduced wild pig and rusa deer were the major target species. Hunting in our study area has shifted from a purely subsistence activity towards a more commercial form at least partly due to the emergence of markets created by Indonesian transmigrants. Although the hunting of non-indigenous and certain native species might be sustainable, the maintenance of populations of large threatened species will require sensitive management.