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  • Item
    An evaluation of the ecological niche of Orf virus (Poxviridae): Challenges of distinguishing broad niches from no niches.
    (PLOS One, 2024-01-18) Peterson, A Townsend
    Contagious ecthyma is a skin disease, caused by Orf virus, creating great economic threats to livestock farming worldwide. Zoonotic potential of this disease has gained recent attention owing to the re-emergence of disease in several parts of the world. Increased public health concern emphasizes the need for a predictive understanding of the geographic distributional potential of Orf virus. Here, we mapped the current distribution using occurrence records, and estimated the ecological niche in both geographical and environmental spaces. Twenty modeling experiments, resulting from two- and three-partition models, were performed to choose the candidate models that best represent the geographic distributional potential of Orf virus. For all of our models, it was possible to reject the null hypothesis of predictive performance no better than random expectations. However, statistical significance must be accompanied by sufficiently good predictive performance if a model is to be useful. In our case, omission of known distribution of the virus was noticed in all Maxent models, indicating inferior quality of our models. This conclusion was further confirmed by the independent final evaluation, using occurrence records sourced from the Centre for Agriculture and Bioscience International. Minimum volume ellipsoid (MVE) models indicated the broad range of environmental conditions under which Orf virus infections are found. The excluded climatic conditions from MVEs could not be considered as unsuitable owing to the broad distribution of Orf virus. These results suggest two possibilities: that the niche models fail to identify niche limits that constrain the virus, or that the virus has no detectable niche, as it can be found throughout the geographic distributions of its hosts. This potential limitation of component-based pathogen-only ENMs is discussed in detail.
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    Physiognomy datasets across two sub-montane tropical forests: Bakossi National Park and Mt. Nlonako in the continental Cameroon mountains
    (Elsevier, 2024-04-25) Sainge, Moses Nsanyi; Lyonga, Ngoh Michael; Nchu, Felix; Peterson, A. Townsend
    The submontane forests in the Congo Basin have not been studied sufficiently in terms of floristic diversity, biomass, and geographic distribution. The region's lack of resources and rugged terrain are among the barriers to sampling biodiversity. This study focuses on two understudied submontane forest areas, Bakossi National Park (BNP) and Mt. Nlonako (MN), which form part of the continental Cameroon Mountains and are believed to have high species diversity and endemism. However, significant gaps exist in biodiversity data across the continental Cameroon Mountains. This study is the first detailed quantitative survey of forests in the BNP and MN through permanent plot sampling. The results of this study can be used to guide policies for managing montane ecosystems in Cameroon and enhancing conservation efforts. The study also provides an opportunity for long-term monitoring of forest health and REDD+ status.
  • Publication
    Predicting climate-driven distribution shifts in Hyalomma marginatum (Ixodidae)
    (Cambridge University Press, 2023-07-31) Hekimoglu, Olcay; Elverici, Can; Cem Kuyucu, Arda
    Hyalomma marginatum is an important tick species which is the main vector of Crimean–Congo haemorrhagic fever and spotted fever. The species is predominantly distributed in parts of southern Europe, North Africa and West Asia. However, due to ongoing climate change and increasing reports of H. marginatum in central and northern Europe, the expansion of this range poses a potential future risk. In this study, an ecological niche modelling approach to model the current and future climatic suitability of H. marginatum was followed. Using high-resolution climatic variables from the Chelsa dataset and an updated list of locations for H. marginatum, ecological niche models were constructed under current environmental conditions using MaxEnt for both current conditions and future projections under the ssp370 and ssp585 scenarios. Models show that the climatically suitable region for H. marginatum matches the current distributional area in the Mediterranean basin and West Asia. When applied to future projections, the models suggest a considerable expansion of H. marginatum's range in the north in Europe as a result of rising temperatures. However, a decline in central Anatolia is also predicted, potentially due to the exacerbation of drought conditions in that region.
  • Publication
    Predicting climate-driven distribution shifts in Hyalomma marginatum (Ixodidae)
    (Cambridge University Press, 2023-07-31) Hekimoglu, Olcay; Elverici, Can; Cem Kuyucu, Arda
    Hyalomma marginatum is an important tick species which is the main vector of Crimean–Congo haemorrhagic fever and spotted fever. The species is predominantly distributed in parts of southern Europe, North Africa and West Asia. However, due to ongoing climate change and increasing reports of H. marginatum in central and northern Europe, the expansion of this range poses a potential future risk. In this study, an ecological niche modelling approach to model the current and future climatic suitability of H. marginatum was followed. Using high-resolution climatic variables from the Chelsa dataset and an updated list of locations for H. marginatum, ecological niche models were constructed under current environmental conditions using MaxEnt for both current conditions and future projections under the ssp370 and ssp585 scenarios. Models show that the climatically suitable region for H. marginatum matches the current distributional area in the Mediterranean basin and West Asia. When applied to future projections, the models suggest a considerable expansion of H. marginatum's range in the north in Europe as a result of rising temperatures. However, a decline in central Anatolia is also predicted, potentially due to the exacerbation of drought conditions in that region.
  • Publication
    Species Delimitation, Phylogenomics, and Biogeography of Sulawesi Flying Lizards: A Diversification History Complicated by Ancient Hybridization, Cryptic Species, and Arrested Speciation
    (Oxford University Press, 2023-04-19) Mcguire, Jimmy A; Huang, Xiaoting; Reilly, Sean B; Iskandar, Djoko T; Wang-Claypool, Cynthia Y; Werning, Sarah; Chong, Rebecca A; Lawalata, Shobi Z S; Stubbs, Alexander L; Frederick, Jeffrey H; Brown, Rafe M; Evans, Ben J; Arifin, Umilaela; Riyanto, Awal; Hamidy, Amir; Arida, Evy; Koo, Michelle S; Supriatna, Jatna; Andayani, Noviar; Hall, Robert
    The biota of Sulawesi is noted for its high degree of endemism and for its substantial levels of in situ biological diversification. While the island’s long period of isolation and dynamic tectonic history have been implicated as drivers of the regional diversification, this has rarely been tested in the context of an explicit geological framework. Here, we provide a tectonically informed biogeographical framework that we use to explore the diversification history of Sulawesi flying lizards (the Draco lineatus Group), a radiation that is endemic to Sulawesi and its surrounding islands. We employ a framework for inferring cryptic speciation that involves phylogeographic and genetic clustering analyses as a means of identifying potential species followed by population demographic assessment of divergence-timing and rates of bi-directional migration as means of confirming lineage independence (and thus species status). Using this approach, phylogenetic and population genetic analyses of mitochondrial sequence data obtained for 613 samples, a 50-SNP data set for 370 samples, and a 1249-locus exon-capture data set for 106 samples indicate that the current taxonomy substantially understates the true number of Sulawesi Draco species, that both cryptic and arrested speciations have taken place, and that ancient hybridization confounds phylogenetic analyses that do not explicitly account for reticulation. The Draco lineatus Group appears to comprise 15 species—9 on Sulawesi proper and 6 on peripheral islands. The common ancestor of this group colonized Sulawesi ~11 Ma when proto-Sulawesi was likely composed of two ancestral islands, and began to radiate ~6 Ma as new islands formed and were colonized via overwater dispersal. The enlargement and amalgamation of many of these proto-islands into modern Sulawesi, especially during the past 3 Ma, set in motion dynamic species interactions as once-isolated lineages came into secondary contact, some of which resulted in lineage merger, and others surviving to the present.
  • Publication
    The Fergana Valley Is an Isolate of Biodiversity: A Discussion of the Endemic Herpetofauna and Description of Two New Species of Alsophylax (Sauria: Gekkonidae) from Eastern Uzbekistan
    (MDPI, 2023-08-04) Nazarov, Roman A.; Abduraupov, Timur V.; Shepelya, Evgeniya Yu.; Gritsina, Mariya A.; Melnikov, Daniel A.; Buehler, Matthew D.; Lapin, Jack D.; Poyarkov, Nikolay A.; Grismer, Jesse L.
    The high level of endemism in Fergana Valley has been well documented in numerous studies for various groups of animals and plants. In a relatively small area, there are 45 endemic plant species, five endemic insect species, and five endemic reptile species. In surveying this area for data on distribution, abundance, acoustics, and genetic samples for species of reptiles, we discovered two new species of gecko from the genus Alsophylax. Phylogenetic analyses of mitochondrial DNA sequences indicate the relatives of these new species are the even-fingered gecko, Alsophylax pipiens, and the southern even-fingered gecko, Alsophylax laevis, located hundreds of kilometers to the northwest and southwest of the Fergana Valley. The threats to these new endemic species are significant given the amount of continued agricultural development that involves new territories previously considered “unsuitable” for any species of significance that is leading to the further reduction in, fragmentation of, and degradation of the remaining natural ecosystems in the Fergana Valley. The conservation of these rare and locally endemic species depends directly on the readiness of the state to create areas with IUCN I and II protection. The many studies documenting levels of endemism, along with the data published in this study, are the basis for the justification for state-protected areas in the Fergana Valley.
  • Publication
    Anthropogenic uranium signatures in turtles, tortoises, and sea turtles from nuclear sites
    (Oxford University Press, 2023-08-22) Conrad, Cyler; Inglis, Jeremy; Wende, Allison; Sanborn, Matthew; Mukundan, Nilesh; Price, Allison; Tenner, Travis; Wurth, Kimberly; Naes, Benjamin; Fair, Jeanne; Middlebrook, Earl; Gaukler, Shannon; Whicker, Jeffrey; Gerard, Jamie L; Aguilera, Washington Tapia; Gibbs, James P; Wolf, Blair; Kattil-deBrum, Tonie K; Hagemann, Molly; Seminoff, Jeffrey A; Brys, Timothy; Brown, Rafe; Derieg, Katrina M
    Chelonians (turtles, tortoises, and sea turtles) grow scute keratin in sequential layers over time. Once formed, scute keratin acts as an inert reservoir of environmental information. For chelonians inhabiting areas with legacy or modern nuclear activities, their scute has the potential to act as a time-stamped record of radionuclide contamination in the environment. Here, we measure bulk (i.e. homogenized scute) and sequential samples of chelonian scute from the Republic of the Marshall Islands and throughout the United States of America, including at the Barry M. Goldwater Air Force Range, southwestern Utah, the Savannah River Site, and the Oak Ridge Reservation. We identify legacy uranium (235U and 236U) contamination in bulk and sequential chelonian scute that matches known nuclear histories at these locations during the 20th century. Our results confirm that chelonians bioaccumulate uranium radionuclides and do so sequentially over time. This technique provides both a time series approach for reconstructing nuclear histories from significant past and present contexts throughout the world and the ability to use chelonians for long-term environmental monitoring programs (e.g. sea turtles at Enewetok and Bikini Atolls in the Republic of the Marshall Islands and in Japan near the Fukushima Daiichi reactors).
  • Publication
    Range-wide phylogenomics of the Great Horned Owl (Bubo virginianus) reveals deep north-south divergence in northern Peru Emily N. Ostrow,corresponding author Lucas H. DeCicco, and Robert G. Moyle
    (Peej, 2023-08-09) Ostrow, Emily N.; DeCicco, Lucas H.; Moyle, Robert G.
    The Great Horned Owl (Bubo virginianus) inhabits myriad habitats throughout the Americas and shows complex patterns of individual and geographic morphological variation. The owl family Strigidae is known to follow ecogeographic rules, such as Gloger’s rule. Although untested at the species level, these ecogeographic rules may affect B. virginianus plumage coloration and body size. Previous studies have indicated that, despite this species’ morphological variability, little genetic differentiation exists across parts of their range. This study uses reduced representation genome-wide nuclear and complete mitochondrial DNA sequence data to assess range-wide relationships among B. virginianus populations and the disputed species status of B. v. magellanicus (Magellanic or Lesser Horned Owl) of the central and southern Andes. We found shallow phylogenetic relationships generally structured latitudinally to the north of the central Andes, and a deep divergence between a southern and northern clade close to the Marañón Valley in the central Andes, a common biogeographic barrier. We identify evidence of gene flow between B. v. magellanicus and other subspecies based on mitonuclear discordance and F-branch statistics. Overall differences in morphology, plumage coloration, voice, and genomic divergence support species status for B. v. magellanicus.
  • Publication
    Identifying Climatic Drivers of Hybridization with a New Ancestral Niche Reconstruction Method
    (Oxford University Press, 2023-04-19) Folk, Ryan A; Gaynor, Michelle L; Engle-Wrye, Nicholas J; O'Meara, Brian C; Soltis, Pamela S; Soltis, Douglas E; Guralnick, Robert P; Smith, Stephen A; Grady, Charles J; Okuyama, Yudai
    Applications of molecular phylogenetic approaches have uncovered evidence of hybridization across numerous clades of life, yet the environmental factors responsible for driving opportunities for hybridization remain obscure. Verbal models implicating geographic range shifts that brought species together during the Pleistocene have often been invoked, but quantitative tests using paleoclimatic data are needed to validate these models. Here, we produce a phylogeny for Heuchereae, a clade of 15 genera and 83 species in Saxifragaceae, with complete sampling of recognized species, using 277 nuclear loci and nearly complete chloroplast genomes. We then employ an improved framework with a coalescent simulation approach to test and confirm previous hybridization hypotheses and identify one new intergeneric hybridization event. Focusing on the North American distribution of Heuchereae, we introduce and implement a newly developed approach to reconstruct potential past distributions for ancestral lineages across all species in the clade and across a paleoclimatic record extending from the late Pliocene. Time calibration based on both nuclear and chloroplast trees recovers a mid- to late-Pleistocene date for most inferred hybridization events, a timeframe concomitant with repeated geographic range restriction into overlapping refugia. Our results indicate an important role for past episodes of climate change, and the contrasting responses of species with differing ecological strategies, in generating novel patterns of range contact among plant communities and therefore new opportunities for hybridization. The new ancestral niche method flexibly models the shape of niche while incorporating diverse sources of uncertainty and will be an important addition to the current comparative methods toolkit. [Ancestral niche reconstruction; hybridization; paleoclimate; pleistocene.]
  • Publication
    Movement patterns and habitat use for the sympatric species: Gambelia wislizenii and Aspidoscelis tigris
    (Wiley Open Access, 2023-08-10) McAlpine-Bellis, Elizabeth; Utsumi, Kaera L.; Diamond, Kelly M.; Klein, Janine; Gilbert-Smith, Sophia; Garrison, Grace E.; Eifler, Maria A.
    Movement is an important characteristic of an animal's ecology, reflecting the perception of and response to environmental conditions. To effectively search for food, movement patterns likely depend on habitat characteristics and the sensory systems used to find prey. We examined movements associated with foraging for two sympatric species of lizards inhabiting the Great Basin Desert of southeastern Oregon. The two species have largely overlapping diets but find prey via different sensory cues, which link to their differing foraging strategies—the long‐nosed leopard lizard, Gambelia wislizenii, is a visually‐oriented predator, while the western whiptail, Aspidoscelis tigris, relies more heavily on chemosensory cues to find prey. Using detailed focal observations, we characterized the habitat use and movement paths of each species. We placed markers at the location of focal animals every minute for the duration of each 30‐min observation. Afterward, we recorded whether each location was in the open or in vegetation, as well as the movement metrics of step length, path length, net displacement, straightness index, and turn angle, and then made statistical comparisons between the two species. The visual forager spent more time in open areas, moved less frequently over shorter distances, and differed in patterns of plant use compared to the chemosensory forager. Path characteristics of step length and turn angle differed between species. The visual predator moved in a way that was consistent with the notion that they require a clear visual path to stalk prey whereas the movement of the chemosensory predator increased their chances of detecting prey by venturing further into vegetation. Sympatric species can partition limited resources through differences in search behavior and habitat use.
  • Publication
    An elevational shift facilitated the Mesoamerican diversification of Azure‐hooded Jays (Cyanolyca cucullata) during the Great American Biotic Interchange
    (Wiley Open Access, 2023-08-15) McCormack, John E.; Hill, Molly M.; DeRaad, Devon A.; Kirsch, Eliza J.; Reckling, Kelsey R.; Mutchler, Marquette J.; Ramirez, Brenda R.; Campbell, Russell M. L.; Salter, Jessie F.; Pizarro, Alana K.; Tsai, Whitney L. E.; Bonaccorso, Elisa
    The Great American Biotic Interchange (GABI) was a key biogeographic event in the history of the Americas. The rising of the Panamanian land bridge ended the isolation of South America and ushered in a period of dispersal, mass extinction, and new community assemblages, which sparked competition, adaptation, and speciation. Diversification across many bird groups, and the elevational zonation of others, ties back to events triggered by the GABI. But the exact timing of these events is still being revealed, with recent studies suggesting a much earlier time window for faunal exchange, perhaps as early as 20 million years ago (Mya). Using a time‐calibrated phylogenetic tree, we show that the jay genus Cyanolyca is emblematic of bird dispersal trends, with an early, pre‐land bridge dispersal from Mesoamerica to South America 6.3–7.3 Mya, followed by a back‐colonization of C. cucullata to Mesoamerica 2.3–4.8 Mya, likely after the land bridge was complete. As Cyanolyca species came into contact in Mesoamerica, they avoided competition due to a prior shift to lower elevation in the ancestor of C. cucullata. This shift allowed C. cucullata to integrate itself into the Mesoamerican highland avifauna, which our time‐calibrated phylogeny suggests was already populated by higher‐elevation, congeneric dwarf‐jays (C. argentigula, C. pumilo, C. mirabilis, and C. nanus). The outcome of these events and fortuitous elevational zonation was that C. cucullata could continue colonizing new highland areas farther north during the Pleistocene. Resultingly, four C. cucullata lineages became isolated in allopatric, highland regions from Panama to Mexico, diverging in genetics, morphology, plumage, and vocalizations. At least two of these lineages are best described as species (C. mitrata and C. cucullata). Continued study will further document the influence of the GABI and help clarify how dispersal and vicariance shaped modern‐day species assemblages in the Americas.
  • Publication
    Advancing the central role of non-model biorepositories in predictive modeling of emerging pathogens
    (Public Library of Science, 2023-06-15) Colella, Jocelyn P.; Marlon E. Cobos; Salinas, Irene; Cook, Joseph A.; The PICANTE Consortium
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    Biodiversity of Philippine marine fishes: A DNA barcode reference library based on voucher specimens
    (Nature Research, 2023-06-24) Bemis, Katherine E.; Girard, Matthew G.; Santos, Mudjekeewis D.; Carpenter, Kent E.; Deeds, Jonathan R.; Pitassy, Diane E.; L. Flores, Nicko Amor; Hunter, Elizabeth S.; Driskell, Amy C.; Macdonald, Kenneth S., III; Weigt, Lee A.; Williams, Jeffrey T.
    Accurate identification of fishes is essential for understanding their biology and to ensure food safety for consumers. DNA barcoding is an important tool because it can verify identifications of both whole and processed fishes that have had key morphological characters removed (e.g., filets, fish meal); however, DNA reference libraries are incomplete, and public repositories for sequence data contain incorrectly identified sequences. During a nine-year sampling program in the Philippines, a global biodiversity hotspot for marine fishes, we developed a verified reference library of cytochrome c oxidase subunit I (COI) sequences for 2,525 specimens representing 984 species. Specimens were primarily purchased from markets, with additional diversity collected using rotenone or fishing gear. Species identifications were verified based on taxonomic, phenotypic, and genotypic data, and sequences are associated with voucher specimens, live-color photographs, and genetic samples catalogued at Smithsonian Institution, National Museum of Natural History. The Biodiversity of Philippine Marine Fishes dataset is released herein to increase knowledge of species diversity and distributions and to facilitate accurate identification of market fishes.
  • Publication
    Advancing the central role of non-model biorepositories in predictive modeling of emerging pathogens
    (Public Library of Science, 2023-06-15) Colella, Jocelyn P.; Cobos, Marlon E.; Salinas, Irene; Cook, Joseph A.
  • Publication
    Two Decades of Wildlife Pathogen Surveillance: Case Study of Choclo orthohantavirus and Its Wild Reservoir Oligoryzomys costaricensis
    (MDPI, 2023-06-17) Gonzalez, Publio; Salazar, Jacqueline R.; Salinas, Tybbysay P.; Avila, Mario; Colella, Jocelyn P.; Dunnum, Jonathan L.; Glass, Gregory E.; Gonzalez, Gloria; Juarez, Enos; Lindblade, Kimberly; Pile, Edwin; Mendoza, Yaxelis; Pascale, Juan Miguel; Armien, Anibal G.; Cook, Joseph A.; Armien, Blas
    The Costa Rican pygmy rice rat (Oligoryzomys costaricensis) is the primary reservoir of Choclo orthohantavirus (CHOV), the causal agent of hantavirus disease, pulmonary syndrome, and fever in humans in Panama. Since the emergence of CHOV in early 2000, we have systematically sampled and archived rodents from >150 sites across Panama to establish a baseline understanding of the host and virus, producing a permanent archive of holistic specimens that we are now probing in greater detail. We summarize these collections and explore preliminary habitat/virus associations to guide future wildlife surveillance and public health efforts related to CHOV and other zoonotic pathogens. Host sequences of the mitochondrial cytochrome b gene form a single monophyletic clade in Panama, despite wide distribution across Panama. Seropositive samples were concentrated in the central region of western Panama, consistent with the ecology of this agricultural commensal and the higher incidence of CHOV in humans in that region. Hantavirus seroprevalence in the pygmy rice rat was >15% overall, with the highest prevalence in agricultural areas (21%) and the lowest prevalence in shrublands (11%). Host–pathogen distribution, transmission dynamics, genomic evolution, and habitat affinities can be derived from the preserved samples, which include frozen tissues, and now provide a foundation for expanded investigations of orthohantaviruses in Panama.
  • Publication
    Ethnodemographic characterization of stroke incidence and burden of disease in hospital discharge records in Ecuador
    (Frontiers Media, 2023-02-08) Carrington, Sarah J.; Romero-Alvarez, Daniel; Coral-Almeida, Marco; Vela, Andrea; Henríquez-Trujillo, Aquiles Rodrigo; Mascialino, Guido
    Introduction: Stroke is the second most common cause of death and disability-adjusted life years (DALYs) globally. However, the incidence and impact of stroke by ethnicity and gender is frequently distinct. This is particularly the case in Ecuador where geographic and economic marginalization are often correlated with ethnic marginalization and the extent to which females lack the same opportunities as their male counterparts. The aim of this paper is to investigate the differential impacts in terms of stroke diagnosis and burden of disease by ethnicity and gender, using hospital discharge records over the years 2015–2020. Methods: This paper calculates stroke incidence, and fatality rates using hospital discharge and death records over the years 2015–2020. The DALY package in R was employed to calculate the Disability Adjusted Life Years lost due to stroke in Ecuador. Results: The results show that while the incidence rate of stroke in males (64.96 per 100,000 persons-year) is higher than that for females on average (57.84 per 100,000 persons-year), males accounted for 52.41% of all stroke cases and 53% of all surviving cases. Thus, hospital data suggests that females had a higher death rate when compared to males. Case fatality rates also differed significantly by ethnicity. The highest fatality rate corresponded to the Montubio ethnic group (87.65%), followed by Afrodescendants (67.21%). The estimated burden of disease of stroke calculated using Ecuadorian hospital records (2015–2020) varied from 1,468 to 2,991 DALY per 1,000 population on average. Discussion: Differences in the burden of disease by ethnic group are likely to reflect differential access to care by region and socio-economic group, both of which are frequently correlated with ethnic composition in Ecuador. Equitable access to health services remains an important challenge in the country. The gender discrepancy in fatality rates suggests that there is a need for targeted educational campaigns to identify stroke signs early, especially in the female population.
  • Publication
    What constitutes a community? A co-occurrence exploration of the Costa Rican avifauna
    (Taylor and Francis, 2023-04-27) Velde, Mélusine F.; Besozzi, Elizabeth M.; Krochuk, Billi A.; Henderson, Kate M.; Tsuru, Brian R.; Restrepo, Sara Velásquez; Garrod, Holly M.; Cooper, Jacob C.
    The concept of a “community” as a form of organization for natural biological systems is both widespread and widely accepted within the ecological and biological sciences. Communities have been defined as groups of organisms that interact in ways that denote interdependence between individuals and taxa (e.g. as defined by “food webs”) but they have also been defined as groups of co-occurring organisms that are assumed to interact by virtue of their shared spatiotemporal existence. The latter definition has been debated and challenged in the literature, with mounting evidence for co-occurrence being more indicative of coincident ecological niches in space and time rather than being evidence of ecological interaction or dependency. Using a dataset of 460 Costa Rican bird species divided into breeding and non-breeding season datasets, we empirically demonstrate the ways in which co-occurrence can create illusory communities based on similar occupied ecological niches and similar patterns of co-occurrence at different times of year. We discuss the importance of discerning coincidental co-occurrence from true ecological interactions that would manifest a true community, and further address the importance of differentiating communities of co-occurrence from communities of demonstrable ecological interaction. While co-occurrence is a necessary aspect of interspecific interactions, we discuss and demonstrate here that such co-occurrence does not make a community, nor should explicit patterns of co-occurrence be seen as evidence for evolutionarily important ecological interactions.
  • Publication
    Mapping the global distribution of invasive pest Drosophila suzukii and parasitoid Leptopilina japonica: Implications for biological control
    (PeerJ, 2023-04-24) Nair, Rahul R.; Peterson, A. Townsend
    Insect pest invasions cause significant damage to crop yields, and the resultant economic losses are truly alarming. Climate change and trade liberalization have opened new ways of pest invasions. Given the consumer preference towards organic agricultural products and environment-friendly nature of natural pest control strategies, biological control is considered to be one of the potential options for managing invasive insect pests. Drosophila suzukii (Drosophilidae) is an extremely damaging fruit pest, demanding development of effective and sustainable biological control strategies. In this study, we assessed the potential of the parasitoid Leptopilina japonica (Figitidae) as a biocontrol agent for D. suzukii using ecological niche modeling approaches. We developed global-scale models for both pest and parasitoid to identify four components necessary to derive a niche based, target oriented prioritization approach to plan biological control programs for D. suzukii: (i) potential distribution of pest D. suzukii, (ii) potential distribution of parasitoid L. japonica, (iii) the degree of overlap in potential distributions of pest and parasitoid, and (iv) biocontrol potential of this system for each country. Overlapping suitable areas of pest and parasitoid were identified at two different thresholds and at the most desirable threshold (E = 5%), potential for L. japonica mediated biocontrol management existed in 125 countries covering 1.87 × 107 km2, and at the maximum permitted threshold (E = 10%), land coverage was reduced to 1.44 × 107 km2 in 121 countries. Fly pest distributional information as a predictor variable was not found to be improving parasitoid model performance, and globally, only in half of the countries, >50% biocontrol coverage was estimated. We therefore suggest that niche specificities of both pest and parasitoid must be included in site-specific release planning of L. japonica for effective biocontrol management aimed at D. suzukii. This study can be extended to design cost-effective pre-assessment strategies for implementing any biological control management program.
  • Publication
    Simulating the dynamics of dispersal and dispersal ability in fragmented populations with mate-finding Allee effects
    (Wiley Open Access, 2023-04-21) Schauf, Andrew J.; Jones, Matthew F.; Oh, Poong
    We consider the spatial propagation and genetic evolution of model populations comprising multiple subpopulations, each distinguished by its own characteristic dispersal rate. Mate finding is modeled in accord with the assumption that reproduction is based on random encounters between pairs of individuals, so that the frequency of interbreeding between two subpopulations is proportional to the product of local population densities of each. The resulting nonlinear growth term produces an Allee effect, whereby reproduction rates are lower in sparsely populated areas; the distribution of dispersal rates that evolves is then highly dependent upon the population's initial spatial distribution. In a series of numerical test cases, we consider how these dynamics affect lattice-like arrangements of population fragments, and investigate how a population's initial fragmentation determines the dispersal rates that evolve as a habitat is colonized. First, we consider a case where initial population fragments coincide with habitat islands, within which death rates differ from those that apply outside; the presence of inhospitable exterior regions exaggerates Allee effect-driven reductions in dispersal ability. We then examine how greater distances separating adjacent population fragments lead to more severe reductions in dispersal ability. For populations of a fixed initial magnitude, fragmentation into smaller, denser patches leads not only to greater losses of dispersal ability, but also helps ensure the population's long-term persistence, emphasizing the trade-offs between the benefits and risks of rapid dispersal under Allee effects. Next, simulations of well-established populations disrupted by localized depopulation events illustrate how mate-finding Allee effects and spatial heterogeneity can drive a population's dispersal ability to evolve either downward or upward depending on conditions, highlighting a qualitative distinction between population fragmentation and habitat heterogeneity. A final test case compares populations that are fragmented across multiple scales, demonstrating how differences in the relative scales of micro- and macro-level fragmentation can lead to qualitatively different evolutionary outcomes.
  • Publication
    Leptospirosis in Ecuador: Current Status and Future Prospects
    (MDPI, 2023-03-29) Calvopiña, Manuel; Romero-Alvarez, Daniel; Vasconez, Eduardo; Valverde-Muñoz, Gabriela; Trueba, Gabriel; Garcia-Bereguiain, Miguel Angel; Orlando, Solon Alberto
    The location of Ecuador—an equatorial nation—favors the multiplication and dispersal of the Leptospira genus both on the Pacific Coast and in the Amazon tropical ecoregions. Nevertheless, leptospirosis epidemiology has not been fully addressed, even though the disease has been recognized as a significant public health problem in the country. The purpose of this literature review is to update knowledge on the epidemiology and geographical distribution of Leptospira spp. and leptospirosis in Ecuador to target future research and develop a national control strategy. A retrospective literature search using five international, regional, and national databases on Leptospira and leptospirosis including humans, animals, and environmental isolations of the bacteria and the disease incidence in Ecuador published between 1919 and 2022 (103 years) with no restriction on language or publication date was performed. We found and analyzed 47 publications including 22 of humans, 19 of animals, and two of the environments; three of these covered more than one of these topics, and one covered all three (i.e., One Health). Most (60%) of the studies were conducted in the Coastal ecoregion. Twenty-four (51%) were published in international journals, and 27 (57%) were in Spanish. A total of 7342 human and 6314 other animal cases were studied. Leptospirosis was a frequent cause of acute undifferentiated febrile illness in the Coast and Amazon and was associated with rainfall. All three major clusters of Leptospira—pathogenic, intermediate, and saprophytic—were identified from both healthy and febrile humans, the environment, and animals; moreover, nine species and 29 serovars were recorded over the three Ecuadorian ecoregions. Leptospira infections were diagnosed in livestock, companion, and wild animals from the Amazon and the Coast regions along with sea lions from the Galápagos Islands. Microscopic-agglutination test was the diagnostic tool most widely used. Three reviews covering national data on outpatients and inpatients determined the varied annual incidence and mortality rate, with males being more commonly affected. No human cases have been reported in the Galápagos Islands. Genomic sequences of three pathogenic Leptospira were reported. No studies on clinical ground, antibiotic resistance, or treatment were reported, nor were control programs or clinical-practice guidelines found. The published literature demonstrated that leptospirosis was and still is an endemic disease with active transmission in the four geoclimatic regions of Ecuador including the Galápagos Islands. Animal infections, distributed in mainland and insular Ecuador, pose a significant health risk for humans. Nationwide epidemiological surveys—encouraging more research on the fauna and environment with appropriate sampling design on risk factors for human and animal leptospirosis, Leptospira genotyping, increased laboratory capability, and readily available official data—are required to improve our understanding of transmission patterns and to develop effective national intervention strategies with the intention of applying One Health approaches.