Tool For Conservation Management Research Articles

Assessing the Conservation Value of Artificial and Natural Reefs via Ichthyoplankton Spatio-Temporal Dynamics

The distribution of fish eggs and larvae (ichthyoplankton) reflects spawning and nursery areas as well as dispersal routes. This study’s goal is to demonstrate how the identification of ichthyoplankton species and stages and their spatial distribution among natural reefs (NRs) and artificial reefs (ARs) may serve as decision-making tools in conservation and fishery management. Natural reefs exhibited an eight-times higher abundance of eggs, as well as the highest abundance of larvae in the yolk-sac and preflexion phases. In contrast, ARs had the highest abundance of larvae in the flexion and postflexion phases. Natural reefs may serve as breeding grounds for Scaridae, Labridae, and Mugilidae; whereas, ARs may serve as breeding sites for Lutjanidae, Synodontidae, Carangidae, Fistularidae, and Haemulidae. Our study revealed differences between ARs and NRs, which demonstrate the potential of artificial reefs to expand the supply and settlement options of reef fishes and consequently can lead to increased fish production with potential benefits to adjacent fishing areas through connectivity. Thus, ARs as no-take sites can be effective tools for both fishery management and biodiversity conservation. The findings highlight the potential use of ichthyoplankton tools and the importance of considering both types of reefs in marine conservation and management efforts.

Sea turtle density surface models along the United States Atlantic coast

Spatially explicit estimates of marine species distribution and abundance are required to quantify potential impacts from human activities such as military training and testing, fisheries interactions, and offshore energy development. There are 4 protected species of sea turtle (loggerhead, green, Kemp’s ridley, and leatherback) commonly found along the east coast of the USA, our study area, and which require impact assessments. Data from 7 different survey organizations were used to create density surface models for the 4 sea turtle species utilizing 1.2 million km of line-transect surveys. A substantial portion (29.7%) of available sightings were not identified to the species level. Not including these sightings would underestimate density, so a conditional random forest model was used to assign unidentified sightings to species. Higher densities of loggerhead, green, and Kemp’s ridley sea turtles were predicted south of the Outer Banks in cool months, transitioning northwards in late spring to occupy seasonal neritic habitats. The highest leatherback densities were predicted off the coasts of Georgia and Florida. Leatherbacks were also predicted throughout offshore areas. The predicted distribution patterns generally matched satellite tracking and strandings data, indicating the models reproduced established seasonal movements. Surveys rarely detect sea turtles smaller than 40 cm, so these age classes are not represented. The models are the first for the study area to apply availability bias estimates developed in or near the study area and attempt to classify unidentified sightings to the species level, providing an updated, critical tool for conservation management along the eastern seaboard.

Morphological and Habitat Quality of Salmonid Streams and their Relationship with Fish-Based Indices in Aotearoa New Zealand and Ontario (Canada).

Habitat degradation is one of the major reasons for freshwater species decline. Hydrogeomorphological processes (such as sediment transport, bank erosion, and flooding) operate at the catchment scale and determine habitat features in river reaches. However, habitat quality indices and restoration for freshwater fish species are often implemented at small spatial scales of a few hundred metres. The Morphological Quality Index (MQI) considers fluvial processes at larger scales as well as channel forms, human impacts, and historical changes, but few studies have assessed its relevance for ecosystem health. We investigated relationships between the MQI, habitat quality (using the Qualitative Habitat Evaluation Index, QHEI), land cover, and fish metrics (number of fish species, index of biotic integrity (IBI), and trout biomass) in 26 salmonid streams in Aotearoa New Zealand and Southern Ontario, Canada. We found a significant correlation between the MQI and QHEI, and both metrics were correlated with urban and native forest proportion in the catchment. However, we found no relation between the MQI and the proportion of agricultural land in the catchment, while the QHEI was correlated with agricultural land in the riparian zone, highlighting the importance of vegetated riparian buffers in providing fish habitat. Establishing a strong correlation with fish metrics remains challenging. Nevertheless, a modified MQI targeting ecological health could be used as an effective management tool for aquatic conservation.

Natural grazing by horses and cattle promotes bird diversity in a restored European alluvial grassland.

A challenge in grassland conservation is to maintain both the openness and the heterogeneity of the habitat to support the diversity of their animal communities, including birds-a taxon that is known to be sensitive to disturbance. An increasingly used management tool in European grassland conservation, especially in rewilding projects, is grazing by large herbivores such as horses and cattle. These grazers are believed to create and maintain patchy landscapes that promote diversity and richness of other species, but their influence on birds is often debated by conservationists, who raise concerns about the impact of disturbance by the grazers. Our aim was to examine the relationship between the abundance and species richness of birds across four foraging guilds and the area utilization patterns of Highland cattle and Konik horses in an alluvial grassland in France. We also aimed to examine the influence of land cover and season on the spatial distribution, including abundance and species richness, of different bird guilds present in the grazed area. We used GPS-collars on all grazers and recorded their positions on an hourly basis over a study period of 1.5 years, assessing patterns of area usage. We counted birds weekly along three transects to describe their distribution within the grazed area and carried out land-cover surveys to describe the habitat. To assess how species richness and abundance of birds of different guilds were related to grazer density, season, and habitat characteristics, we used GAMM models in a spatially explicit framework. We also compared bird numbers at our main study site with a nearby non-grazed control area. The number of birds in the grazed area was about twice the number in the non-grazed control area. Within the grazed area, the abundance of open-area foraging birds increased with increasing grazer density. The number of woodland-foraging birds was also positively correlated with grazer density but less so than open-area foraging birds. The number of individuals in the aerial and wetland bird guilds was not correlated with the density of grazers. Most bird species and individuals were observed on open landscapes scattered with woody patches and waterbodies, and on areas with moderate grazer density. Low-intensity grazing represents a potentially important management tool in creating heterogeneity in alluvial grasslands, thereby promoting suitable habitat for a diverse assemblage of bird species.

Integral Management Zones: A novel strategy for marine bivalve production in the Gulf of California, Mexico

Abstract The development of area‐based tools that combine fishing, aquaculture and repopulation practices is increasingly necessary and important to conserve ecosystems, promote sustainable use of marine resources and contribute to the well‐being of the people that rely on them. In the Gulf of California, Mexico, two small‐scale fishers' cooperatives were granted a Permit for Exploratory Aquaculture of bivalve species, and their members decided to set three zones within those concessions: (i) a zone for natural seed collection and repopulation, (ii) a no‐take zone and (iii) an area where fishing was allowed. This management arrangement, named by them as the Integral Management Zone (Zona de Manejo Integral), was conceived as an innovative alternative to the current policy tools available in the Mexican General Law for Sustainable Fisheries and Aquaculture. The natural collection of bivalve larvae in the artificial collectors was sufficient to allow the development of the repopulation project. Based on hydrodynamic models of larval dispersal, self‐recruitment was low, and the collection of seed depended on distant sources. The broader scale (regional) connectivity source–sink patterns should be considered in the design stages of the Integral Management Zones. The implementation of the Integral Management Zones can complement other conservation and fisheries management tools available in Mexican environmental and fisheries laws. The approach envisioned to implement this tool is participative, with a meaningful role of local fishers in the decisions concerning the use of these zones, with a supportive engagement of governmental and other stakeholders (e.g., academia and civil society organizations).

What is the risk of overcollecting for translocation? An opportunistic assessment of a wingless grasshopper

AbstractTranslocation is an increasingly used tool in conservation management, but there is a risk that source populations are overcollected. The risk depends critically on the detection probability and the source population size. We quantified this risk for a wingless grasshopper population in a patch of remnant habitat in suburban Melbourne that was condemned to be cleared for housing development. We collected ∼2000 grasshoppers in five samples spread over 1 month and used the results to estimate the initial population size (∼3400) with high confidence. Despite our perception of substantially depleting the population, we removed only an estimated 60%, and this relatively high fecundity (∼50 eggs per lifetime) annual species had recovered by the following year to near its original density. Wild‐to‐wild translocation is likely to be a low‐cost and effective strategy in the conservation of many invertebrates, and our findings highlight the feasibility of using natural source populations.

Stationary distribution of a stochastic reaction–diffusion predator–prey model with additional food and fear effect

Providing additional food supplements to predators is one of the crucial and effective tools for biological conservation and pest management, which has been widely recognized and validated by theoretical and experimental scientists. This paper focuses on the existence and uniqueness of stationary distribution of a stochastic reaction–diffusion predator–prey model that incorporates additional food for predator and fear effect for prey. It reveals that spatial diffusion is beneficial for maintaining the steady state of the model, whereas environment white noise has a negative effect.

An ensemble approach to species distribution modelling reconciles systematic differences in estimates of habitat utilization and range area

Abstract Species distribution models (SDMs) are an important tool for conservation and resource management. However, managers are often interested in derived quantities such as range or area occupied, and how these are calculated can have a large impact. Ecosystem‐based management typically requires spatial information about species distributions, which is increasingly generated from SDMs that are then processed to identify occupied habitat. Many types of SDMs exist, but there is little research regarding how this model‐choice affects outcomes when defining occupied habitat, in part because these models generate different types of output. We fit a suite of five SDMs to data for 208 species/life stage combinations in three marine ecosystems while ensuring that they all estimate a ‘common currency’ of numerical abundance. We then calculate out‐of‐sample predictive performance to weight these constituents in an ensemble SDM. Results show that this approach can reduce bias arising from a priori specification of individual SDMs resulting in a better fit to survey data (constituent SDMs had a median of 7% higher RMSE). The SDMs had a range of responses relative to the ensemble, with MaxEnt typically predicting a median 1.3% higher area occupied, and negative‐binomial GAMs predicting 21.4% lower area occupied. Two potential methods of identifying the area of occupied habitat from SDM outputs are compared—probability‐based and cumulative density‐based methods. We find that cumulative densities result in smaller estimates of area occupied, and we recommend careful consideration of how model‐choice affects occupied‐habitat estimates in spatial management. Policy implications: Finally, we discuss how the patterns identified during the 5‐year Review of Essential Fish Habitat for Alaska should be carefully considered by managers using SDMs to identify habitat that may be impacted by anthropogenic activities.

A Snapshot into the Lives of Elephants: Camera Traps and Conservation in Etosha National Park, Namibia

Knowledge of elephant movement and grouping patterns in the wild is critical for their management and conservation. Much of these data come from GPS collar data and aerial surveys, which have provided invaluable information, but data from these methods are often limited to small groups or entire populations. Effective elephant management requires both generalized and localized methodologies. Here, we propose the expanded use of camera traps in research relating to elephant localized movements and grouping patterns as an additional tool for elephant conservation management. In this study, we use a battery-powered camera trap to provide daily high-resolution data of African savanna elephant (Loxodonta africana) grouping patterns over the course of an entire year. We present findings on the seasonal and diurnal grouping patterns of elephants at a waterhole in the northeast corner of Etosha National Park from July 2016 to June 2017. The frequency of elephant occurrences varied seasonally and diurnally across all group types (solitary male, male, family, and mixed groups), while group sizes did not vary seasonally, except for male groups. Solitary males occurred relatively equally throughout the day, while male and mixed groups occurred the most midday, and family groups occurred the most in the afternoon. Additionally, we measured the reliability of research assistants when collecting group type and group size data from the camera trap images. Intra- and inter-observer reliability was excellent among and across research assistants, highlighting the potential for non-specialist observers to have greater involvement in camera trap data collection. Our results support the use of camera trap data where GPS collars and aerial surveys are not feasible and where higher-resolution data are needed for more localized management. Finally, we discuss our experience with two different types of camera traps to highlight the pros and cons of each approach.

BatTool: projecting bat populations facing multiple stressors using a demographic model

Bats provide ecologically and agriculturally important ecosystem services but are currently experiencing population declines caused by multiple environmental stressors, including mortality from white-nose syndrome and wind energy development. Analyses of the current and future health and viability of these species may support conservation management decision making. Demographic modeling provides a quantitative tool for decision makers and conservation managers to make more informed decisions, but widespread adoption of these tools can be limited because of the complexity of the mathematical, statistical, and computational components involved in implementing these models. In this work, we provide an exposition of the BatTool R package, detailing the primary components of the matrix projection model, a publicly accessible graphical user interface (https://rconnect.usgs.gov/battool) facilitating user-defined scenario analyses, and its intended uses and limitations (Wiens et al., US Geol Surv Data Release 2022; Wiens et al., US Geol Surv Softw Release 2022). We present a case study involving wind energy permitting, weighing the effects of potential mortality caused by a hypothetical wind energy facility on the projected abundance of four imperiled bat species in the Midwestern United States.

Vegetation patch dynamics in rangelands: How feedbacks between large herbivores, vegetation and soil fauna alter patches over space and through time

AbstractAimLarge herbivore grazing is a popular conservation management tool to promote vegetation structural diversity of rangelands. However, vegetation patch dynamics, that is, how patches of grazing‐defended tall vegetation and grazer‐preferred short lawns shift over space and time, is poorly understood. Here, we describe a new conceptual framework for patch dynamics within rangelands, combining theories of classical cyclical succession, self‐organization and multitrophic feedbacks between grazers, vegetation and bioturbating soil fauna.LocationWe use the cattle‐grazed salt marsh of the island Schiermonnikoog, The Netherlands, as a model system. The grazed salt marsh is characterized by distinct tall vegetation patches dominated by the grazing‐defended rush Juncus maritimus and grazing‐intolerant grass Elytrigia atherica, surrounded by a matrix of grazing lawn (dominated by Festuca rubra).The FrameworkBased on previous observational and experimental studies, we propose a cyclical patch dynamic where plant species composition and structure transitions through four phases: patch initiation (a) occurs when the grazing‐defended rush J. maritimus establishes in the grazed lawn. Patch establishment (b) follows when the grazing‐intolerant grass E. atherica establishes in the patch due to associational defence by J. maritimus and produces a large amount of litter that attracts the key bioturbating amphipod Orchestia gammarellus. Patch expansion (c) occurs when O. gammarellus activities improve soil properties of the patch, which favours E. atherica growth, leading to E. atherica competitively displacing J. maritimus in the centre of the patch. Patch degeneration (d) follows when cattle enter the enlarged patch to consume E. atherica in the centre, trample the soil, displace O. gammarellus and decrease vegetation cover, opening space for grazing‐lawn species to invade. The cycle restarts when remnants of the rush J. maritimus in the degenerated patches (or individuals recently established from seed dispersal) initiate new patches in the grazing lawn.SynthesisOur proposed patch‐dynamic model provides a means to describe the mechanisms driving vegetation patch dynamics and serves as a foundation for further experimental and observational exploration, not only for this specific system, but more generally for grazed systems worldwide that show patches of typical grazing‐defended and grazer‐preferred vegetation.

Predicting climate change impacts on critical fisheries species in Fijian marine systems and its implications for protected area spatial planning

AbstractAimSpatially explicit protections of coastal habitats determined on the current distribution of species and ecosystems risk becoming obsolete in 100 years if the movement of species ranges outpaces management action. Hence, a critical step of conservation is predicting the efficacy of management actions in future. We aimed to determine how foundational, habitat‐building species will respond to climate change in Fiji.LocationThe Republic of Fiji.MethodsWe develop species distribution models (SDMs) using MaxEnt, General Additive Models and Boosted Regression Trees and publicly available data from the Global Biodiversity Information Facility to predict changes in distribution of suitable habitat for mangrove forests, coral habitat, seagrass meadows and critical fisheries invertebrates under several IPCC climate change scenarios in 2070 or 2100. We then overlay predicted distribution models onto existing Fijian protected area network to assess whether today's conservation measures will afford protection to tomorrow's distributions.ResultsWe found that mangrove suitability is projected to decrease along the Coral Coast and increase northward towards the Yasawa Islands due to precipitation changes. The response of seagrass meadows was predicted to be inconsistent and dependent on the climate scenario. Meanwhile, suitability for coral reefs was not predicted to decline significantly overall. The mangrove crab Scylla serrata, an important resource for fisherwomen in Fiji, is projected to increase in habitat suitability while economically important sea cucumber species will have highly variable responses to climate change.Main conclusionsSpecies distribution models are a critical tool for conservation managers, as linking spatial distribution data with future climate change scenarios can aid in the creation and resiliency of protected area programmes. New protected area designations should consider the future distribution of species to maximize benefits to those taxa.

Importance of conserving a critical wintering ground for shorebirds in the Valinokkam Lagoon—a first study of the avifaunal distribution of the southeastern coast of India

Any new economic activity in a virgin area brings landscape changes, making it essential to document baseline biodiversity areas to understand the impacts on habitats. Avifaunal inventories are critical for previously undocumented areas, especially in a wintering site for shorebirds in the Central Asian Flyway, to formulate site- and species-specific conservation management tools. We present an annotated checklist of avifauna from the Valinokkam Lagoon in the Ramanathapuram district of Tamil Nadu. We recorded the first baseline avifaunal data for 154 species belonging to 16 orders and 46 families from August 2016 to February 2023. Order-wise, Charadriiformes dominated the study site with 47 species; followed by Passeriformes with 39 species and Pelecaniformes with 20 species. Winter visitors constituted 37.6 % (58 species) and one Passage Migrant Rosy Starling Pastor roseus. The relative abundance indicated that 94 species were C (common), 41 species were UC (uncommon), and 19 species were Ra (rare). Eleven Near Threatened (NT) species: Oriental Darter Anhinga melanogaster, Painted Stork Mycteria leucocephala, Black-headed Ibis Threskiornis melanocephalus, Spot-billed Pelican Pelecanus philippensis, Black-tailed Godwit Limosa limosa, Bar-tailed Godwit Limosa lapponica, Great Stone-curlew Esacus recurvirostris, Eurasian Curlew Numenius arquata, Curlew Sandpiper Calidris ferruginea, Red-necked Stint Calidris ruficollis and Red Knot Calidris canutus, one Endangered (EN) species Great Knot Calidris tenuirostris, and one unassessed Hanuman Plover Charadrius seebohmi according to the IUCN Red List category. This baseline data highlights the importance of Valinokkam Lagoon as an important wintering site in the Central Asian Flyway on the southeast coast of India for migratory shorebirds and the need for more conservation priorities for regional endemic birds like Hanuman Plover.
 

Biomass accrual benefits of community-based marine protected areas outweigh their operational costs

The costs and benefits of customary top-down Marine Protected Areas (MPAs) have been studied at length. But the costs and benefits of community-based MPAs –an increasingly common tool in conservation and fisheries management– remain understudied. Here, we quantify the operational costs of maintaining community-based MPA monitoring programs in nine small-scale fishing communities in Mexico. We then compare these costs to the potential extractive use value of invertebrate and fish biomass contained in the reserves. We find that the annual monitoring costs (median: 1,130 MXN/ha; range: 23-3,561 MXN/ha) represent between 0.3% and 55% of the extractive use value of the biomass contained in the reserves (median: 21.31 thousand MXN/ha; 5.22 - 49/12 thousand MXN/ha). These results suggest that the direct monetary benefits of community-based marine conservation can outweigh the costs of monitoring programs, providing further support for these types of management schemes. While further research should explore other mechanisms that would allow fishers to leverage the non-extractive use value of reserves (e.g., tourism) or the non-use value (i.e. existence value of biodiversity) to sustainably finance their conservation efforts, a stop-gap measure to ensuring long-term monitoring costs are covered might include limited extractive use of resources contained in the reserves.

Isolation and characterization of 17 polymorphic microsatellite loci with tri- and tetra-nucleotide repeat motifs for Ayu (Plecoglossus altivelis) using next-generation sequencing.

Ayu or sweetfish, Plecoglossus altivelis, an amphidromous fish ranging in the northwestern Pacific, is economically important inland fisheries and aquaculture resources. Genetic characterization of wild Ayu and derived culture seeds with competent molecular genetic markers is still insufficient for their sustainable use. Microsatellite DNA markers with larger repeat motifs (e.g. tri- and tetra-nucleotide motifs) are convenient and accurate compared with those having mono- and di-nucleotide motifs, but the latter motifs characterized most Ayu microsatellite markers developed previously. Here, we isolated and characterized 17 polymorphic microsatellite DNA markers with tri- and tetra-nucleotide repeat motif using next-generation sequencing. Alleles per locus varied from 6 to 23. The observed and expected heterozygosities ranged from 0.542 to1.000and 0.709to0.951, respectively. Polymorphic information content (PIC) of 15 out of the 17 loci were high (≧ 0.700), suggesting them to be highly informative. Twelve of the 17 loci were used for preliminary assignment test among three collections, and successfully allocated the examined fish to the original populations. The novel polymorphic microsatellite markers developed herein will be useful to examine the genetic diversity and population structure of wild Ayu and the effect of seed transplantation on native populations, providing a tool for conservation and sustainable adaptive management of this species.

Publication and use of genetic tools in conservation management applications—A systematic review

Abstract Genetics tools are used in applied conservation management for taxonomic identification, delineation of management units, management of wild populations, captive breeding and reintroduction and control of invasive species, disease and hybridisation. To assess the extent to which genetic tools are being used for applied conservation management, we conducted a systematic literature review of over 53,767 papers focussing on wildlife research that reported results on species delineation, translocations and population augmentation. We synthesised information on papers that used genetics tools in an expressly applied manner across all wildlife species. We found that the application of genetics tools in conservation management was biased towards fishes, mammals and birds and northern hemisphere locations, especially the United States and Europe. Despite genetics tools being a highly published topic, it was difficult to find published applications of these tools in both the primary and the grey literature. Of the 115 papers on 152 species that could be considered an applied use of a genetics tool expressly for conservation management, only 49 had definable applied outcomes. The remaining 66 made recommendations, but it was often unclear if the recommendations were ever used to make conservation management decisions because of the time‐lag between publication of the initial recommendation and publication of the results of the use of the tool in a conservation management situation, as well as the lack of dissemination in the primary literature. Our study highlights the relative low publication rate of applications of genetics tools compared to the general conservation genetics field. These tools appear to have either a low percentage of translations into publication (‘conservation genetics publishing gap’) or a poor uptake among wildlife conservation managers (‘conservation genetics gap’)—the two are indistinguishable in this review. Policy implications. Conservation genetics tools must be brought to the forefront of conservation policy and management. Users should support the use of systems and accessible databases to increase the uptake of genetics tools for conservation in applied management decisions for wildlife, reducing barriers to disseminating the results to other end users and interested parties.

Assessing the Attractive Effects of Floating Artificial Reefs and Combination Reefs on Six Local Marine Species

Artificial reefs (ARs) have been advocated for and implemented as management tools for recreational fisheries, species conservation, and habitat replacement; however, the research that includes attracting marine species of floating ARs remains in its early stages. Here, two types of floating ARs were designed to evaluate the attractive effects using the occurrence rate and attracting index for six commercially important species (Lateolabrax maculatus, Liza haematocheila, Sebastes schlegelii, Acanthopagrus schlegelii, Litopenaeus vannamei, and Amphioctopus fangsiao) in the Bohai Bay of China; their combined ARs were meanwhile compared with two variants of artificial seagrass beds (SA and SB) and the traditional double-frame artificial reef (TD). All of the designed ARs were effective in attracting experimental species. The ARs with higher shelter areas (SB and TD) showed a better attracting effect. The efficiency of the ARs in attracting different species depended on their life histories. The bottom-mounted ARs were more efficient in attracting demersal species, while the floating ARs attracted epipelagic fish. In addition, the combined reefs had a better attractive effect than single ARs did. Overall, floating ARs and their combined ARs show the potential to deploy especially for attracting epipelagic fishes, although further study is needed.

The habitat-suitability models of the European mole cricket (Gryllotalpa gryllotalpa) as information tool for conservation and pest management

The European mole cricket, Gryllotalpa gryllotalpa, feeds on a wide range of crops and can also damage plants with its burrowing activities. In suitable habitats (like those with damp, rich soils in flood plains), G. gryllotalpa numbers can increase to high levels. On the other hand, the abundance of G. gryllotalpa has dramatically decreased in north-western Europe partly due to direct eradication and excessive pest control. Using habitat suitability modelling, we identified areas suitable for G. gryllotalpa occurrence based on previous reports of its occurrence and based on environmental data. We limited our study area to regions where G. gryllotalpa is the only known Gryllotalpa species. The most important variables in our models were found to be relative air humidity and minimum soil temperature of the coldest month. We suggest that soil temperature is a limiting factor for European mole cricket occurrence in the Czech Republic because most areas in the country experience soil temperatures just below 0 °C, while most reports of G. gryllotalpa occurrence in Europe are from areas where the soil temperature does not drop below 0 °C. The models we have developed can provide information on possible occurrences of the mole cricket and thus improve the decision-making process both in the field of pest control and the conservation of this species.

DNA barcoding of Chinese snakes reveals hidden diversity and conservation needs.

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.

Coexistence of triple, quadruple attractors and Wada basin boundaries in a predator–prey model with additional food for predators

In biological control programs, the provision of additional food is regarded as one of the most useful tools for species conservation and pest management. In a system, providing additional food for predators can distract the predators from the overconsumption of prey (short term) or enhance the predation rate (long term). In the present article, we consider a predator–prey model with Holling type-II functional response by incorporating additional food for the predator species in a discrete-time setup. Here, we intend to explore the impact of additional food on the growth of prey as well as the overall dynamics of the underlying system. We analyze the system dynamics by varying two control parameters, viz, the biomass of additional food and the intrinsic growth rate of prey species simultaneously with the help of Lyapunov exponent and isoperiodic diagrams. Through the simultaneous variation of two parameters, very rich and complex dynamical behaviors of a simple deterministic system can come into view with the presence of structurally stable periodic patterns in the transitional and chaotic zones, which is not looked on only by the variability of one parameter. In this study, we notice the presence of infinite families of different organized periodic structures, like Arnold tongues, shrimp-shaped domains, a new kind of ‘double fishhook’ structures, etc. in the quasiperiodic and chaotic zones of the parameter planes with various kinds of period-adding phenomena. The study also discloses the transition to chaos via shrimp-induced period-bubbling process. We observe the coexistence of double and triple attractors in several different sets of attractors. The most fascinating finding in this study is the coexistence of quadruple attractors, one of the rarest phenomena in ecological systems. The basin boundaries of all these coexisting double, triple, and quadruple attractors are of a very complex nature, they are either fractal basin boundaries or Wada basin boundaries.