Non-native Populations Research Articles

Predator–Prey Reunion: Non-native Coquí Frogs Avoid Their Native Predators

When non-native species are introduced to new areas without their native predators, they may lose their ability to detect and avoid those predators, especially if the behaviors impose some sort of cost. Few studies have investigated whether non-native populations have lost the ability to avoid their native predators. Coquí frogs, which are endemic to Puerto Rico, were introduced to Hawaii in the late 1980s. Our goal was to investigate whether Coquís from Hawaii avoid predators from their native Puerto Rico. To test this, we collected frogs from both ranges and two arthropod predators from Puerto Rico (tailless whip scorpions and tarantulas). We determined experimentally whether frogs from Hawaii and Puerto Rico exhibited the same avoidance behaviors to these predators. We found that frogs from both ranges avoid attack by moving away from predators and that there was no difference in behaviors between the two ranges. Results suggest that, after nearly 20 generations, frogs from Hawaii have not lost their ability to detect and avoid native predators. The antipredator behaviors Coquís exhibit may help them avoid novel predators in their introduced range and may have contributed to their successful invasion.

Self-Compatibility and Reproductive Success of Oenothera drummondii subsp. drummondii: Is It Similar between Native and Non-Native Populations?

The mating system of plants widely distributed can change in native range but also in non-native habitats. Oenothera drummondii, native to the coastal dunes of the Gulf of Mexico, has been introduced to Europe, Africa, Asia and Oceania. Hand self- and cross-pollination were performed to determine compatibility and to compare fruit set, fruit weight, seed set and germination characteristics from natives and non-natives populations and a comprehensive integral reproductive success index (IRSI) was built. Oenothera drummondii exhibited high self-compatibility and mixed reproductive systems in all populations. Characteristics of fruits and seeds from self- and cross-pollination varied within and between native and non-native populations and some had a positive clinal variation in the native range. The IRSI was sensitive to changes of fruit set, seed set and final germination of both self- and cross-pollination, showing differences between native populations. Differences in characteristics of fruits and seeds in the native and non-native ranges suggest the occurrence of distinct selection factors. The mixed reproductive system of O. drummondii suggests it can take advantage of local visitors in the native range, but also can provide advantages for the establishment at non-native sites giving the opportunity to interact with local flower visitors.

Invaders from islands: thermal matching, potential or flexibility?

Abstract Native-range thermal constraints may not reflect the geographical distributions of species introduced from native island ranges in part due to rapid physiological adaptation in species introduced to new environments. Correlative ecological niche models may thus underestimate potential invasive distributions of species from islands. The northern curly-tailed lizard (Leiocephalus carinatus) is established in Florida, including populations north of its native range. Competing hypotheses may explain this distribution: Thermal Matching (distribution reflects thermal conditions of the native range), Thermal Potential (species tolerates thermal extremes absent in the native range) and/or Thermal Flexibility (thermal tolerance reflects local thermal extremes). We rejected the Thermal Matching hypothesis by comparing ecological niche models developed from native vs. native plus invasive distributions; L. carinatus exists in areas of low suitability in Florida as predicted by the native-distribution model. We then compared critical thermal limits of L. carinatus from two non-native populations to evaluate the Thermal Potential and Flexibility hypotheses: one matching native range latitudes, and another 160 km north of the native range that experiences more frequent cold weather events. Critical thermal minima in the northern population were lower than in the south, supporting the Thermal Flexibility hypothesis, whereas critical thermal maxima did not differ.

Validity of photo-oxidative stress markers and stress-related phytohormones as predictive proxies of mortality risk in the perennial herb Plantago lanceolata

Oxidative stress and hormonal regulation are hallmarks of a/biotic stress responses in plants. However, little is known about their linkage with whole-organismal mortality in long-lived species. Here, we examined the validity of photo-oxidative stress markers and stress-related phytohormones as predictive proxies of mortality risk in the perennial herb Plantago lanceolata. Capitalizing on its broad ecological niche, we examined photo-oxidative stress markers (Fv/Fm ratio, contents of chlorophylls, carotenoids, and tocochromanols, and the extent of lipid peroxidation) and stress-related phytohormones (ABA, salicylic acid and jasmonates contents) as proxies of mortality in three populations of sub-tropical and Mediterranean habitats: Virginia (VA, U.S.A.), Catalonia (CAT, Spain), and Queensland (QLD, Australia). Stress markers were measured together with the vital rates of survival, growth, and reproduction on a total of 279 individuals. Stress marker data were collected during the summer and death/survival was monitored after two and four months. Whole-organism mortality was similarly high in both sub-tropical non-native populations (ca. 30 % after a drought in VA and QLD), but lower in the native population (ca. 10 % in CAT). The contents of antioxidants (lutein, zeaxanthin, β-carotene) and the de-epoxidation state of the xanthophyll cycle (DPS) were good proxies of mortality risk in VA and QLD. DPS and all carotenoid contents per unit of chlorophyll were lower four months in advance in dead than in alive plants in VA and QLD, thus suggesting reduced photoprotective capacity increased the mortality risk in non-native populations. We show that whole-organismal mortality in P. lanceolata is associated with a reduced capacity to enhance photoprotection under abiotic stress conditions. The validity of various stress markers as predictive proxies of mortality risk is discussed.

Distribution of the Main Apis mellifera Mitochondrial DNA Lineages in Italy Assessed Using an Environmental DNA Approach.

Simple SummaryThe conservation of the genetic diversity of the native honey bee subspecies is a hot topic in many European countries. Mitochondrial DNA (mtDNA) analyses can provide some information that is useful to monitor the genetic integrity of Apis mellifera populations. A preliminary distribution of the main honey bee mitotypes in Italy was obtained more than 20 years ago. In this study we obtained an updated and more detailed distribution map of the main groups of honey bee mitotypes using an unconventional method that exploits the information derived from the environmental DNA contained in the honey. The results were quite different from the picture taken two decades ago. The African mtDNA lineage was spread all over Italy and not only in Sicily, where it is mainly attached to the A. m. siciliana subspecies, and where it was identified in the previous investigation. A reduction in the frequency of the M lineage was also evident, and, on the other hand, a counterbalanced increase in the C mitotypes was observed in regions all over. The obtained results provided an updated distribution map of the A, C and M groups of mitotypes in Italy, which could be a starting point to design appropriate conservation programs for native honey bee subspecies.Growing interest has been emerging on the need to monitor the genetic integrity of the European Apis mellifera subspecies that could be threatened by the human-mediated dispersion of non-native populations and lines. Mitochondrial DNA (mtDNA) lineages can provide useful information for this purpose. In this study, we took advantage of the environmental DNA (eDNA) contained in the honey, which can be analyzed to detect the main groups of mitotypes of the honey bees that produced it. In this study, we applied this eDNA to produce a distribution map all over the Italian peninsula and the two major islands (Sicily and Sardinia) of the following three honey bee mtDNA lineages: A, C and M. A total of 607 georeferenced honey samples, produced in all Italian regions, was analyzed to detect these lineages. The A lineage was widespread in Sicily, as expected, considering that A. m. siciliana carries the African lineage. Surprisingly, this lineage was also reported in about 14% of all other samples produced in almost all continental regions, and in Sardinia. The applied method obtained an updated distribution map of honey bee mtDNA lineages that could be useful to design policies for the conservation of Italian honey bee genetic resources.

Gastric Cancer in Alaska Native and American Indian People Living in Alaska, 1990-2017.

Alaska Native (AN) people experience a high burden of gastric cancer compared with other US Native and non-Native populations. Previous reports have suggested that gastric cancer in AN people occurs at a younger age and is a more aggressive pathologic type. We evaluated all cases of gastric cancer in AN people from 1990 to 2017 and compared the epidemiologic and pathologic characteristics with the gastric cancers that occurred in the same time in the US white (USW) population. Cancer data were collected by the Alaska Native Tumor Registry and National Cancer Institute's Surveillance, Epidemiology, and End Results Program. Comparisons were performed looking at the age and sex distribution of the affected AN and USW people, as well as the cancer characteristics, including the location, stage, and pathology. The age distribution was significantly different between AN and USW patients (P < 0.001), with a greater proportion of AN people diagnosed younger than 40 years (11% vs 3%, P < 0.0001) and 40-59 years (37% vs 20%, P < 0.0001). In addition, a greater proportion of AN people were diagnosed with distant stage cancer (AN: 48% and USW: 35%, P < 0.0001). The age-adjusted rate of gastric cancer in the AN population was significantly higher than the USW population (20.8 vs 6.7 per 100,000 persons, P < 0.0001). Although there has been a significant decrease in the gastric cancer incidence rate in the USW population, no significant change in incidence was seen in the AN population. This study highlights the disproportionate burden of gastric cancer in the AN population. Further work is needed to address and understand this disparity.

Peopling of the Americas as inferred from ancient genomics.

In less than a decade, analyses of ancient genomes have transformed our understanding of the Indigenous peopling and population history of the Americas. These studies have shown that this history, which began in the late Pleistocene epoch and continued episodically into the Holocene epoch, was far more complex than previously thought. It is now evident that the initial dispersal involved the movement from northeast Asia of distinct and previously unknown populations, including some for whom there are no currently known descendants. The first peoples, once south of the continental ice sheets, spread widely, expanded rapidly and branched into multiple populations. Their descendants-over the next fifteen millennia-experienced varying degrees of isolation, admixture, continuity and replacement, and their genomes help to illuminate the relationships among major subgroups of Native American populations. Notably, all ancient individuals in the Americas, save for later-arriving Arctic peoples, are more closely related to contemporary Indigenous American individuals than to any other population elsewhere, which challenges the claim-which is based on anatomical evidence-that there was an early, non-Native American population in the Americas. Here we review the patterns revealed by ancient genomics that help to shed light on the past peoples who created the archaeological landscape, and together lead to deeper insights into the population and cultural history of the Americas.

Population structure and genetic diversity of non-native aoudad populations

The aoudad (Ammotragus lervia Pallas 1777) is an ungulate species, native to the mountain ranges of North Africa. In the second half of the twentieth century, it was successfully introduced in some European countries, mainly for hunting purposes, i.e. in Croatia, the Czech Republic, Italy, and Spain. We used neutral genetic markers, the mitochondrial DNA control region sequence and microsatellite loci, to characterize and compare genetic diversity and spatial pattern of genetic structure on different timeframes among all European aoudad populations. Four distinct control region haplotypes found in European aoudad populations indicate that the aoudad has been introduced in Europe from multiple genetic sources, with the population in the Sierra Espuña as the only population in which more than one haplotype was detected. The number of detected microsatellite alleles within all populations (< 3.61) and mean proportion of shared alleles within all analysed populations (< 0.55) indicates relatively low genetic variability, as expected for new populations funded by a small number of individuals. In STRUCTURE results with K = 2–4, Croatian and Czech populations cluster in the same genetic cluster, indicating joined origin. Among three populations from Spain, Almeria population shows as genetically distinct from others in results, while other Spanish populations diverge at K = 4. Maintenance of genetic diversity should be included in the management of populations to sustain their viability, specially for small Czech population with high proportion of shared alleles (0.85) and Croatian population that had the smallest estimated effective population size (Ne = 5.4).

Floral traits variation in Oenothera drummondii subsp. drummondii across a wide latitudinal range of native and non-native populations

Plant species with specialized pollination and wide geographic distribution can show variation in the size of floral traits related to environmental local conditions. We studied the floral traits of native and non-native populations of Oenothera drummondii under greenhouse conditions to test if their variation is related to latitude, or their native or non-native origin but displaying similar floral integration. Plants were obtained from seeds collected in six native and six non-native populations distributed across five continents. Eight floral traits were recorded in the flowers produced and examined across latitudinal variation between native and non-native ranges. The floral traits differed between the native and non-native populations, with corolla size the main contributor. Although each floral feature varied independently in response to the latitude and environmental conditions of the populations, there is a clear tendency for size reduction of the structures with latitudinal increase. In contrast, floral integration and flower lifetime remained similar across latitude. The floral traits variation of O. drummondii throughout its native and non-native distribution is the result of the latitudinal gradient and the local population environment. The similarity in floral integration and flower lifespan may favor the specialized reproduction in native populations, whereas flower size-reduction suggests potential local adaptation for pollinators in the non-native populations. The study of flower visitors will help to understand the local adaptation of Oenothera drummondii in each population.

Study on the customs and ecological protection consciousness of Naxi nationality in Lijiang

The Naxi is a unique minority nationality in the southwest border area of China. With its unique national harmonious and traditional customs, the Naxi has gradually formed the concept of development with the surrounding ethnic groups, and has strong customs and habits of being grateful to nature and living in harmony with nature. This paper studies the significance of Naxi people’s natural customs for ecological environment protection by means of literature collection, visiting and questionnaire survey. The results of the study and survey data show that naxi sacrifice natural customs, funeral culture and water source protection have strong ecological protection consciousness and behavior, The local people have a high understanding of traditional customs in cognition and maintenance, which has formed a good demonstration effect on the cultivation of ecological protection consciousness of tourists and non-native population. Therefore, maintaining and carrying forward the excellent national culture of Naxi is of great reference significance for minority areas to practice Xi Jinping’s idea of ecological civilization, protect the ecological environment and build a beautiful China. It also has a worldwide demonstration significance for the ecological environment protection of Lijiang, the world famous city where the Naxi lives.

Perceptions and Experiences of Frontline Urban Indian Organization Healthcare Workers With Infection Prevention and Control During the COVID-19 Pandemic.

Coronavirus disease 2019 (COVID-19) has created significant challenges for outpatient healthcare providers and patients across the United States (U.S.). Forty-one Urban Indian Organizations (UIOs), who provide a wide spectrum of health services for American Indian and Alaska Native (AI/AN) populations and other underinsured and uninsured populations in urban areas across the country, are no exception. The National Council of Urban Indian Health (NCUIH), in collaboration with the U.S. Centers for Disease Control and Prevention (CDC), set out to understand the needs, challenges, and opportunities for improvement in infection prevention and control (IPC) training and systems from the perspective of UIO frontline healthcare workers. As part of the CDC's Project Firstline, NCUIH was chosen as a partner in a national collaborative. The first task was to conduct listening sessions with frontline UIO staff to learn more about IPC practices in the context of the COVID-19 pandemic. Thirty staff from 16 UIOs, representing full ambulatory, limited ambulatory, outreach and referral, and outpatient and residential treatment programs participated in virtual video focus groups in July of 2020. Thematic and content analysis protocols guided data analysis and coding. Analysis of findings generated four major themes: staff adaptation in the context of resilience; responsibility and duty to protect patients, families, and coworkers; mental and emotional issues for UIO staff; and IPC challenges in the context of COVID-19. Participants' challenges ranged from lack of access to personal protective equipment (PPE) to the absence of standardized training. Significant disparities in social determinants of health experienced by Native American and non-Native populations served by UIOs create additional challenges to the delivery of and access to care during the pandemic. The diverse array of tribal cultural values and contexts of the people and communities served by UIOs reportedly serve as both facilitators and barriers to care, awareness, and uptake of infectious disease public health practices.

The I/Indian Not-In-The-Textbook: Native/Indigenous Post-Structuralism, Critical Methodologies, Epistemologies, and Tribal Realities as Agency toward the Decolonization of the Territorial Divide In American Indian Studies Courses

This article focuses upon how, within American Indian Studies courses, there is a necessary border crossing between territorialized Native and non-Native students. Taking the literal borders of Indian reservations, and repositioning these realities as a metaphor for critical epistemological deconstruction, I argue that there is a necessary educational border crossing which is necessary for Native/Indigenous equity and socio-political justice to be realized and acquired as cultural currency. As students within these courses begin to understand, embrace, and challenge American Indian Studies (AIS) courses, and the dynamics of the discipline, there is a self-defined border crossing between, and within, the Native/Indigenous ideological territories, and literal, physical reservation borders, which the curriculum represents. Each student may – or will – find their own point of critical Native/Indigenous inquiry, from which they are challenged and welcomed to embrace, as well as depart from previous scripted Euro American rhetorical references regarding Native/Indigenous cultures. Following this critical epistemology, for the student participant, a new territory of knowledge, cultural, and expressed understanding from, and about, Native/Indigenous Peoples becomes manifest; a new academic frontier is possible. Applying this methodology, for academic decolonization, the i/Indian image/icon need not exist within the textbook(s); the potential for recognizing and decolonizing the physical reservation borders becomes possible. The realities of Native lives – both historic and contemporary – do matter, beyond these limitations and scripted inclusions within textbooks. Whereas a text may prove as a site of disenfranchisement, inequity, and, tribal marginalization, there, then, lies the necessity for Native V/voices to be heard, reviewed, and function as sovereign references and expressions, which advances beyond the terminal reservation borders as agency. This article seeks to challenge pre-determined academic references, mis-representations and re-presentations of Native Peoples, read: the i/Indian image/icon, as well as providing a critique of how Native/Indigenous realities are, then, able to sovereignly relate to the large non-Native population beyond the limitations of a physical reservation border. Taking note that there is no one single educational methodology, which can be applied within American Indian courses, multiple academic perspectives begin to surface, which address the educational process about Native Peoples. The 3 views of Indian education – anthropological/archeological/ethnographic/historical,sympathetic, activist – as I argue, become, and are maintained as antiquated points of articulation, which continue to be employed about Native Peoples, replacing the active dynamics of Native cultures, customs, traditional knowledge, and expressions. This article, therefore, challenges these 3 views of Indian education – anthropological/archeological/ethnographic/historical, sympathetic, activist – noting that the classroom, textbook(s), and their references, mis-representations and re-presentation(s) about Native Peoples, need to be decolonized, following the importance, ideology, dialectics and dynamics of tribal sovereignty, equity, and socio-political justice.

The I/Indian Not-In-The-Textbook: Native/Indigenous Post-Structuralism, Critical Methodologies, Epistemologies, and Tribal Realities as Agency toward the Decolonization of the Territorial Divide In American Indian Studies Courses

This article focuses upon how, within American Indian Studies courses, there is a necessary border crossing between territorialized Native and non-Native students. Taking the literal borders of Indian reservations, and repositioning these realities as a metaphor for critical epistemological deconstruction, I argue that there is a necessary educational border crossing which is necessary for Native/Indigenous equity and socio-political justice to be realized and acquired as cultural currency. As students within these courses begin to understand, embrace, and challenge American Indian Studies (AIS) courses, and the dynamics of the discipline, there is a self-defined border crossing between, and within, the Native/Indigenous ideological territories, and literal, physical reservation borders, which the curriculum represents. Each student may – or will – find their own point of critical Native/Indigenous inquiry, from which they are challenged and welcomed to embrace, as well as depart from previous scripted Euro American rhetorical references regarding Native/Indigenous cultures. Following this critical epistemology, for the student participant, a new territory of knowledge, cultural, and expressed understanding from, and about, Native/Indigenous Peoples becomes manifest; a new academic frontier is possible. Applying this methodology, for academic decolonization, the i/Indian image/icon need not exist within the textbook(s); the potential for recognizing and decolonizing the physical reservation borders becomes possible. The realities of Native lives – both historic and contemporary - do matter, beyond these limitations and scripted inclusions within textbooks. Whereas a text may prove as a site of disenfranchisement, inequity, and, tribal marginalization, there, then, lies the necessity for Native V/voices to be heard, reviewed, and function as sovereign references and expressions, which advances beyond the terminal reservation borders as agency. This article seeks to challenge pre-determined academic references, mis-representations and re-presentations of Native Peoples, read: the i/Indian image/icon, as well as providing a critique of how Native/Indigenous realities are, then, able to sovereignly relate to the large non-Native population beyond the limitations of a physical reservation border. Taking note that there is no one single educational methodology, which can be applied within American Indian courses, multiple academic perspectives begin to surface, which address the educational process about Native Peoples. The 3 views of Indian education – anthropological/archeological/ethnographic/historical, sympathetic, activist - as I argue, become, and are maintained as antiquated points of articulation, which continue to be employed about Native Peoples, replacing the active dynamics of Native cultures, customs, traditional knowledge, and expressions. This article, therefore, challenges these 3 views of Indian education - anthropological/archeological/ethnographic/historical, sympathetic, activist - noting that the classroom, textbook(s), and their references, mis-representations and re-presentation(s) about Native Peoples, need to be decolonized, following the importance, ideology, dialectics and dynamics of tribal sovereignty, equity, and socio-political justice.

Botany is the root and the future of invasion biology.

Botany is the root and the future of invasion biology.

Non-native prey species supporting fish assemblage biomass in a Neotropical reservoir

The present study aimed to investigate the role of four non-native invertebrates in supporting fish biomass as well as their influence on the carbon flow into the Volta Grande reservoir food web. The fish samples were carried out quarterly between October 2015 and July 2016 using gillnets. At the sampled sites, four non-native invertebrates (golden mussel, Asian clam, trumpet snail and Amazonian prawn), which are potential prey for fish in the Volta Grande reservoir, were collected by targeted sampling using a Petersen-type bottom dredger and semi-circular sieves. The gut contents of the fish were collected and analyzed under stereoscope, and samples of muscle tissue of these fish, as well as the four non-native invertebrate species sampled, were submitted for isotopic analysis. Results obtained by the present study, by both gut content and stable isotopic analyses, pointed to a trophic structure where non-native species represent not only a strong component of the fish community, but also their main carbon source. Based on gut contents and isotopic mixing models, we found that together, non-native prey are essential carbon sources for the fish fauna, fuelling more than 40.0% of the biomass in four dominant fish species. The consumption rate of non-native bivalves by the native omnivorous fish Leporinus friderici suggested these filter-feeding organisms potentially constitute an important trophic connection between littoral consumers and pelagic energy sources. In addition, non-native prey were also prominent carbon sources for non-native fish, fuelling more than half of the biomass in peacock bass and silver croaker, suggesting these prey have a fundamental role in maintaining non-native fish populations in this system. Our results may help to understand fundamental ecological issues bringing to light the extent to which these new combinations of species influence the energy flow and ecosystem properties of the Volta Grande reservoir.

A Case of Mistaken Identity: Genetic and Anatomical Evidence Reveals the Cryptic Invasion of Xenopus tropicalis in Central Florida

Nonnative species are drivers of global change, affecting biodiversity and burdening society with economic costs. Effective management of an invasion relies on the ability to make accurate predictions about the target species' spread and impact. This requires knowledge of the target species' biology, making taxonomic validation critical. Even so, external morphology is still widely used to determine the species identity of novel invaders. Here, we show that a nonnative pipid frog population in Riverview, Florida, USA, initially identified as African Clawed Frog (Xenopus laevis), is a cryptic invasion of Tropical Clawed Frog (Xenopus tropicalis) and the only known nonnative population of this species. We used DNA sequence data and osteology from high-resolution microcomputed tomography to confirm this identification. Furthermore, we conducted field surveys to delineate the population's invaded range in Florida. We detected the presence of adult X. tropicalis at 22 sites and larvae at a subset of 12 sites, representing an occupied area of approximately 1,630 ha. Differing body size and physiology of these two species of Xenopus suggest considerable differences in their impact, spread, and potential geographic range.

Comparative gut content analysis of invasive mosquitofish from Italy and Spain.

Eastern mosquitofish (Gambusia holbrooki) are among the most widely introduced freshwater species globally. To gain a better understanding of feeding patterns in non‐native populations, and which local factors may influence them at the population level, we carried out gut content analysis on 163 specimens from nine invasive populations in Italy and Spain. Based on previous studies, we predicted that (a) mosquitofish are omnivores with a preference for detritus and cladocerans; (b) they display size‐ and population‐specific differences in gut morphologies and diet, with larger fish feeding more intensively over a wider range of prey items; and (c) some of the variation would be associated with differences in local environmental and climatic factors. Our results confirmed our first prediction, because mosquitofish fed on a variety of diet items, among which detritus and Cladocera dominated. However, not a single diet item was shared among all populations. Congruent with our second prediction, we further identified size‐ and population‐specific differences in the occurrence of some diet items and gut morphologies. However, observed patterns in dietary habits did not seem to be driven by the environmental and climatic variables we had quantified. The fairly variable diet likely aids invasion success and helps explain the ubiquity of invasive mosquitofish across Italy and Spain, as mosquitofish seem to be able to rely on whatever a local habitat provides. We further propose that size‐specific differences likely capture the substantial sexual size dimorphism (males are smaller than females), while population‐specific differences are likely the result of differences in local prey abundance. The lack of an influence of temperature on dietary habits suggests that mosquitofish feeding ecology may be less impacted by rising temperatures than other freshwater fish species. If true, then this suggests climate change‐induced effects may further exacerbate the competitive superiority of mosquitofish over native species in the future.

Diet of the American Bullfrog Lithobates catesbeianus Naturalized on Okinawajima, Ryukyu Archipelago, Japan

Abstract: The diet of the nonnative American Bullfrog Lithobates catesbeianus occurring in Ogimi Village of Okinawajima, Ryukyu Archipelago, is investigated. Seventy two of 89 frogs (nine adults, five subadults, and 58 juveniles) captured had food items in its stomach. We identified a total of 64 taxa from 253 food items. Our analyses show that (1) the diet consists mainly of terrestrial prey, (2) mollusks and vertebrates are the essential prey groups for adults and subadults, and (3) odonates, mollusks, and arachnids are the main prey for juveniles. Such dietary habits are quite different from those of several conspecific nonnative populations in mainland Japan and other regions. Part of this is most likely related to the absence of the frog's favorite prey, nonnative American crayfish Procambarus clarkii, in the study area. We also confirm the predation of a poisonous newt Cynops ensicauda popei (Salamandridae) and several aquatic insects by this frog and present some implications for these results.

Evaluation of management factors affecting the relative success of a brook trout eradication program using YY male fish and electrofishing suppression

Removal of non-native fish populations can be crucial to the conservation of native species, but often presents a complex challenge for managers. The goal of Trojan Y chromosome (TYC) programs is to skew the non-native sex ratio until only males remain, leading to eradication. We present results from a simulation model used to explore effects of alternative management approaches on an in-progress mechanical removal and TYC program to eradicate non-native brook trout (Salvelinus fontinalis). Simulation results indicated that stocking fingerling YY males (∼137 mm) was more effective than stocking catchable-sized YY males (∼230 mm), although questions about intercohort competition warrant further investigation. Increasing the proportion of mature fingerling YY males reduced treatment time by increasing the number of YY male spawners and increasing density-dependent mortality on young, mature wild brook trout. Maximizing the spatial distribution of YY male releases may be crucial to program success but is also dependent upon immediate dispersal movements. Principles derived from our results can be broadly applied to the management of other aquatic invaded systems using TYC programs to eradicate non-native species.

Living in isolation for almost 40 years: molecular divergence of the 28S rDNA and COI sequences between French and Polish populations of the cave beetle Speonomus normandi hydrophilus (Jeannel, 1907)

The paper gives the results of the first studies on the molecular divergence between native and non-native populations of Speonomus normandi hydrophilus (Jeannel, 1907). This species is endemic to Massif Arize in the Central Pyrenees (France), and represents highly specialised organisms that live underground. In 1982, one hundred specimens of S. normandi hydrophilus had been experimentally introduced into the Dzwonnica Cave (Poland). Since then, a numerous population has developed in the Towarna-Dzwonnica cave system, and the neighbouring Cabanowa Cave. After almost 40 years of isolation between native and non-native populations, the genetic variations were examined using the COI and 28S rDNA genes. Analyses of the haplotypes of 28S showed one common haplogroup, which confirms the origin of the Polish group. The differentiation of haplotypes for the COI marker was high for both the French and Polish populations. Altogether 18 haplotypes of this marker have been detected, 12 in the French population and 9 in the Polish. However, only a portion of the haplotypes is shared between the native and introduced population.