Disjunct Distribution Research Articles

Alpine travellers in the Carpathians: The story of two rock‐dwelling snails told by genes and fossils

AbstractAimVarious species distributed in the Alps have their disjunct occurrences in the Carpathians. Fossil evidence for some woodland snails of Alpine distribution suggests that they colonized the Carpathians during the Holocene forest optimum or later. Here, we focus on disjunct Carpathian populations of the rock‐dwelling alpine snail Pyramidula saxatilis. As it occupies very stable habitats, that is, high‐elevation limestone rocks, one can assume its potential survival in Carpathian refugia over the glacial period(s). For comparison, the more widespread and warm‐climate P. pusilla is analysed.LocationEurope.TaxonPyramidula saxatilis and P. pusilla.MethodsWe analysed the genetic diversity of P. saxatilis and P. pusilla populations across their entire ranges using mitochondrial DNA and nuclear DNA markers. Seven fossil mollusc successions from the area where P. saxatilis occurs in the Carpathians were analysed and dated using the radiocarbon method. Habitat suitability models of both species were calculated for selected time periods since the Last Glacial Maximum.ResultsAll Carpathian P. saxatilis populations were genetically homogeneous and similar to those from the Eastern Alps. In P. pusilla, we found a genetically distinct lineage in the southern Western Carpathians. Both species were found in three fossil profiles since the Middle Holocene, and in one already in the Late Glacial. Habitat suitability models suggested the fluctuations of suitable conditions in the Carpathians driven by summer precipitation, especially for P. saxatilis.Main ConclusionsOur results suggest that the Carpathian populations of P. saxatilis represent a post‐LGM colonization from the Eastern Alps triggered by climatic changes, mainly by the increase in summer precipitation during the Late Glacial interstadials and Middle Holocene. The evidence for P. pusilla is similar, but also suggests rare long‐term survival in the Carpathian microrefugia. The palaeoecological evidence indicates a possible threat to high‐elevation species from future fluctuations in precipitation regimes.

Host-specific monogeneans parasitizing freshwater fish: The ecology and evolution of host-parasite associations.

Monogenea (Platyhelminthes), mainly gill and fin ectoparasites of fish, are often recognized as host specific and morphologically and ecologically diverse. These parasites exhibit high species diversity at the level of host species or individual fish specimens. Using case studies, especially those widely performed in Dactylogyrus parasitizing cyprinoid fish, this article presents current knowledge on the ecology and evolution of congeneric gill monogeneans. The important aspects of the ecology of congeneric monogeneans are highlighted, in particular: host specificity expressed at several host levels (from strict specificity to phylogenetic specificity), microhabitat specificity expressed by restricted positions on fish gills to facilitate intraspecific mating, and the link between microhabitat preference and morphological adaptation (i.e., sclerotized structures of the haptor) or reproductive isolation. From the evolutionary perspective, this study focused on the processes of the speciation and diversification of congeneric monogeneans, highlighting the role of host switch as the most prominent coevolutionary event, accompanied in some cases mostly by intrahost speciation or cospeciation, as revealed by cophylogenetic studies. Here, important knowledge on evolutionary patterns of host specificity, microhabitat specificity, and morphological adaptation is presented. Host-specific monogeneans may represent an important tool for studying the historical biogeography of their hosts. Specifically, in the case of freshwater fish hosts exhibiting disjunctive distribution, they reflect both historical and contemporary contacts. The role of host-specific congeneric monogeneans in revealing historical intercontinental and intracontinental contacts between freshwater fish is highlighted. Finally, the importance of the role of genetic coadaptation, limiting the presence of host-specific monogeneans in hybrid fish, is emphasized.

Influence of climate factors on the global dynamic distribution of Tsuga (Pinaceae)

Throughout the Quaternary period, climate change has significantly influenced plant distribution, particularly affecting species within the genus Tsuga (Endl.) Carrière. This climatic impact ultimately led to the extinction of all Tsuga species in Europe. Today, there are ten recognized species of Tsuga worldwide, one of listed as a vulnerable species and four as near-threatened species. The genus Tsuga exhibits a disjunctive distribution in East Asia (EA), eastern North America (ENA), and western North America (WNA). It is crucial to comprehend the mechanisms underlying these distributional changes and to identify key climate variables to develop effective conservation strategies for Tsuga under future climate scenarios. In this study, we applied the maximum entropy (MaxEnt) model by combining distribution data for Tsuga with abundant pollen fossil data. Our objective was to investigate the climate factors that shape the distribution of Tsuga, identify climate thresholds, and elucidate distribution dynamics in the context of significant climate changes over the past 1070 thousand years (ka). Our findings highlight the pivotal role of precipitation as the key climate factor affecting the distribution of Tsuga. Specifically, in EA, summer precipitation was the key driver, while in North America (NA), winter precipitation exerted greater importance. Moreover, we observed similarities in climatic requirements between Tsuga species in Europe and EA, and declines in summer precipitation and winter temperature were major factors contributing to the extinction of Tsuga species in Europe. Quaternary glacial and interglacial fluctuations exerted substantial impacts on Tsuga distribution dynamics. The disappearance of Tsuga species in the Korean Peninsula may have occurred during the LGM (Last Glacial Maximum). The potential suitable area for Tsuga species in EA expanded during the cold periods, while in NA, it contracted. In the future, climate change may result Tsuga distribution area contraction in both the EA and NA. Our study has identified distinct response patterns of Tsuga in various geographic regions to Quaternary climate change and offers corresponding suggestions for Tsuga conservation. In the future, it will be imperative to prioritize the conservation of natural Tsuga distributions in EA and NA, with a focus on the impacts of precipitation fluctuation on the dynamic distribution of this genus.

First record of Dermanura gnoma for the threatened Pernambuco Endemism Center, northern Atlantic Forest, with phylogenetic insights.

Dermanura gnoma (Handley, 1987) is a phyllostomid bat that occurs in South America. In Brazil, most of the records are concentrated in the Amazon Forest, with sparse data from Cerrado and Atlantic Forest. This study presents the first record of D. gnoma for Alagoas state, and for the Pernambuco Endemism Center (PEC), the most threatened region of the Brazilian Atlantic Forest, characterized by its high rate of endemism, habitat loss, and fragmentation. The species was surveyed at Murici Ecological Station and its identification was supported by morphological and molecular data. We provide the first COI and CYTB gene sequences for this species in the entire Atlantic Forest. Phylogenetic analyses reveal that the generated sequences were recovered in the same clade as the published sequences of D. gnoma from the Amazonian Forest, corroborating the disjunct distribution pattern between Amazonia and PEC, as already reported for other vertebrate taxa. Also, this record increases the number of bat species to 71 for the PEC and extends the geographic distribution of D. gnoma by 758 kilometers to the northeast of its range.

Disjunct distribution of Hesperotettixspeciosus (Orthoptera, Acrididae) from the Black Belt Prairie of Alabama, United States.

Inventories of the flora and insect fauna of the Black Belt Prairie of Mississippi and Alabama have documented disjunct populations of species broadly distributed in the Great Plains, including two grasshopper species. During a recent survey of a large privately-owned prairie remnant in Sumter Co., Alabama, we documented a disjunct population of a third grasshopper species - Hesperotettixspeciosus, extending the known distribution of this species significantly eastwards. The discovery of this population is surprising due to the number of previous survey efforts of the Black Belt, Alabama and Mississippi overall and exemplifies the importance of conservation on private lands.

Fritillaria meleagris L. (Liliaceae) in the Kharkiv Region: ecological preferences, conservation problems

Fritillaria meleagris L. is a рalearctic species with a disjunct distribution. It is protected at the national level in Ukraine, listed as "vulnerable" in the Red Data Book. Most of the data on the species distribution, as well as on the status and stability of its populations, have been obtained for the Carpathian region. Much less information is available for F. meleagris in the Forest Steppe, especially for its left-bank part. The article presents the results of the study of the peculiarities of F. meleagris distribution in the Kharkiv Region and provides information on the structure of coenopopulations and their ecological and coenotic preferences. Problems and prospects for this species conservation are also considered. The studies cover the biotopes of the Merla River valley and its tributary, the Merchyk River (the Dnipro River basin) in an area of more than 35 square km. In the Kharkiv Region, the F. meleagris coenopopulations were found mainly in grass-type biotopes. These are usually secondary post-forest meadows of the Molinio-Arrhenatheretea Tx. 1937 class. Only one coenopopulation is located in a tree-type biotope (mixed floodplain forest with Quercus robur L., Ulmus laevis Pall., Alnus glutinosa (L.) Gaertn., Salix alba L., Padus avium Mill., Populus аlba L., P. deltoides Marshall, P. tremula L., Acer negundo L., А. tataricum L., A. campestris L., without a pronounced dominant). The specificity of the ecological regimes of the studied localities of F. meleagris has been clarified by the phytoindication method. As a rule, they are damp (less often, fresh) forest-meadow habitats with full, but uneven (temporarily excessive) wetting of the root layer of the soil. The soils are moderately aerated, weakly acidic (pH 5.5–6.5), enriched with salts, but with insignificant carbonate content, and often relatively poor in terms of mineral nitrogen. The climate is characterized by submicrothermal conditions with signs of subaridity and subcontinentality. We have not detected any significant variability of conditions (both edaphic and climatic) in the studied localities. They are more or less optimal for the existence of F. meleagris. In all the F. meleagris localities studied, the change in the hydrological regime due to the reclamation of floodplain remains a risk factor but does not pose an immediate threat. The existence of forest coenopopulations in glades is threatened by overgrowth of trees and shrubs (the invasion of Populus tremula and Acer negundo is particularly dangerous). The decrease in the number of meadow coenopopulations is a result of plowing and burning. Currently, in the Kharkiv Region, F. meleagris is protected in Slobozhanskyі National Nature Park (1 locality) and in Kapranskyі Botanical Reserve of local importance (11 localities). Monitoring of the existing localities outside the protected areas and their inclusion into the expansion zone of the Slobozhanskyі National Nature Park is an important condition for their preservation.

Passage of spores of the dung moss Tayloria callophylla (Splachnaceae) through an avian digestive tract—a novel mode of dispersal?

The dispersal of reproductive material plays a key role in the ecology of plants. Dung mosses (Splachnaceae), have evolved to utilise insects to disperse spores to habitat sites consisting of dung or dead animals—a marked departure from the wind based spore dispersal seen in other mosses. However, adapting to insect dispersal likely precludes long distance airborne dispersal, and limits dispersal events to the movements of the spore bearing insect. However, there are several disjunct populations of these mosses, incompatible with insect dispersal, raising questions over the manner of their origin. Hypotheses put forward include the dispersal of the mosses to these sites by birds. Here, the possibility that insectivorous birds could internally transport spores is explored by feeding insects bearing spores to captive myna birds. We tested if the spores of the New Zealand dung moss, Tayloria callophylla, can survive gut passage. Ultimately 9 of 10 dung samples produced viable moss colonies after a period of 30 days, demonstrating the survival of the spores through an avian digestive tract. Our results provide evidence for a unique model of dispersal in dung mosses, where a spore bearing insect is eaten by a bird that eats insects transports the spores in its gut over a much greater distance than otherwise likely with the insect alone.

Habitat suitability assessment for tule elk in the San Francisco Bay and Monterey Bay areas

While California’s statewide tule elk (Cervus canadensis nannodes) population has recovered from two or three individual survivors in the late 19th century, the subspecies exists today in numerous widely disjunct populations, leaving vast areas of the species’ former range uninhabited. Large unoccupied areas of historic tule elk range include the Santa Cruz Mountains and the northern Diablo and northern Santa Lucia ranges. Natural range expansion by existing populations into these areas is blocked by major highways and urban development; although, before considering tule elk translocations, it is necessary to assess the habitat suitability there. To this end, we fit a resource selection function (RSF) using generalized linear mixed models to GPS collar data collected from nearby radio collared tule elk and used several environmental GIS layers to capture important habitat characteristics. We fit the RSF in a habitat use versus availability framework with only linear and quadratic terms and used stepwise model selection ranked by AICc to maximize its generalizability, enabling transferability to our unoccupied study area. We also used k-fold cross validation to evaluate our RSF and found it predicted habitat within the San Luis Reservoir herd well. The fit habitat relationships mostly followed expectations based on tule elk ecology, including positive responses to herbaceous vegetation cover and waterbody proximity, and negative responses to high tree cover and high puma habitat suitability. Our RSF accurately predicted currently occupied elk habitat as suitable and found well over 500,000 ha (2,000 mi2) of suitable but unoccupied habitat throughout the northern Diablo Range, the inland and coastal sides of the Santa Cruz Mountains, and the northern Santa Lucia Range. Assuming translocations, and construction and improvement of highway wildlife crossings, our results support the potential for re-establishing tule elk in these regions, which are more coastal and mesic than the species’ current habitat in the central Diablo and northern Gabilan ranges.

Effect of translocation on home range and movements of giant gartersnakes

Conservation translocations are often used to connect disjunct populations or reintroduce them to otherwise suitable areas from which they have become locally extinct. Translocations, however, can alter wildlife movements and increase their exposure to hazards such as predation, thus increasing their risk of mortality. The giant gartersnake, Thamnophis gigas, is a wetland-dependent threatened species that has lost > 90% of its historical habitat. Certain species recovery may depend on the success of translocations in restoring populations. We translocated snakes from two donor sites—one managed wetland and one rice agriculture site—to a third restored wetland in Sacramento County, California, USA, to evaluate the impact of translocations on home ranges and movements. Translocated snakes had smaller home ranges after translocation for the 95% and 100% MCP estimation, had smaller net displacements, but had similar measures of sinuosity (index that measures the curvature of a movement path), total distance moved, and start-to-end distance compared to their individual measurements before translocation. Landscape type, however, had the greatest effect on home range estimates and movement measures, with resident snakes from the rice agriculture site having greater home ranges and net displacements, and greater, less sinuous seasonal movement paths than snakes from both the donor and recipient wetland sites. Results varied depending on the specific metric, but overall, translocated snakes tended to have intermediate values for home range size, movement distances, and sinuosity compared to the two resident groups. Our results suggest that although translocation did affect movement and space use relative to resident snakes, its effect depended on the donor habitat from which translocated snakes were removed. Because irregular movements are often linked to low survival after translocation, it is encouraging that translocated snakes did not move more than snakes from a donor rice agriculture site, a landscape that represents much habitat for remaining populations.

Rhynchospora waytii (Cyperaceae): A New Species with an Intriguing Disjunct Distribution in Brazil and Argentina

Abstract— During the first author’s doctoral research, in part developed at the New York Botanical Garden and guided by William Wayt Thomas, several new species of Rhynchospora were discovered when revising NY herbarium specimens. In this study, we describe and name one of these species as Rhynchospora waytii, in honor of this renowned sedge specialist and friend. Rhynchospora waytii is closely related to R. nanuzae but displays distinguishing characteristics such as broader leaves, inconspicuous rhizomes, and larger spikelets and stylopodia. It also exhibits a peculiar disjunct distribution, occurring in Brazil and Argentina, which is explored here with models of geographical range evolution and suitable area of occupancy. Our analysis suggests that suitable habitats have historically existed along the Atlantic coast, extending to the La Plata estuary, near the location where the Argentinian specimens were collected.

Disjunct habitat of cryptic Terebellides (Annelida, Trichobranchidae) species shows a phylogenetic link between polychaetes from the White and the North Seas

Understanding the distribution and biodiversity of marine species is crucial for developing effective conservation strategies and maintaining the health of global ecosystems. Advancements in molecular data utilization have significantly improved our understanding of biodiversity within the genus Terebellides. In this study, we conducted a phylogenetic analysis on polychaete samples from the Kandalaksha Bay, White Sea, revealing their affiliation with a putative undescribed species of the genus Terebellides found in two locations of the North Sea. Interestingly, this species was not detected in the Norwegian and Barents Seas, leading us to propose a disjunct distribution scenario for this Terebellides species. This unique distribution pattern might be attributed to the succession of polychaetes by new species, facilitated by the Gulf Stream and a climate change role in driving shifts in species' ranges and altering marine ecosystem dynamics.

Biogeographic analysis based on phylogenomic data supports multiple ancient dispersals that facilitated the eastern Asia–North America–Mexico disjunction in the subfamily Linnaeoideae (Caprifoliaceae)

AbstractThe small subfamily Linnaeoideae of Caprifoliaceae exhibits a disjunct distribution in Eurasia and North America, including Mexico, with most taxa occurring in eastern Asia or Mexico and the monospecific Linnaea Gronov. ex L. having a circumboreal to north temperate distribution. We sampled 17 of the 20 species representing all Linnaeoideae genera and used nuclear (target enrichment) and complete plastome sequence data to reconstruct the phylogeny. Our results show strong topological conflicts between nuclear and plastid data, especially concerning Dipelta Maxim. and Diabelia Landrein, supporting hybridization events complicating the deep diversification. Nuclear data were used for divergence time estimation and ancestral area reconstruction. The divergence time between the Mexican Vesalea M. Martens & Galeotti and the Linnaea clade was dated to 39.5 Ma, with a 95% highest posterior density of 28.2 Ma (mid‐Oligocene) to 45.2 Ma (mid‐Eocene). Reconstructed ancestral areas support a widespread common ancestor of Linnaea plus Vesalea in Mexico and at least another area (eastern Asia, North America, or Europe). The biogeographic analysis, including fossils, supports the ancestral range of Linnaeoideae to be widespread in central and western China + Europe + Mexico, or eastern and northern Asia + central and western China + Mexico, or central and western China + North America + Mexico. The North Atlantic and/or the Bering land bridges may be important in the widespread distribution across continents in the Northern Hemisphere. Our study highlights the importance of utilizing fossils in biogeographic inferences andusing data from different genomes while reconstructing deep and shallow phylogenies of organisms.

Movement of an imperiled esocid fish in an agricultural drain

Animal movement is increasingly affected by human alterations to habitat and climate change. In wetland systems, widespread hydrologic alterations from agriculture have changed the shape, function, and stability of shallow streams and wetland habitats. These changes in habitat quality and quantity may be especially consequential for freshwater fishes such as Grass Pickerel (Esox americanus vermiculatus), a small predatory fish found in disjunct populations across southern Ontario and listed as Special Concern under Canada’s Species at Risk Act. To characterize Grass Pickerel movement response to stream-channel alterations, Fisheries and Oceans Canada implemented a tracking study to monitor the movements of a Grass Pickerel population in an agricultural drain on the Niagara Peninsula (Ontario, Canada). From 2009 to 2013, 2007 Grass Pickerel were tagged and tracked in the 37.3 km2 Beaver Creek watershed using a combination of mark-recapture surveys and eight fully automated passive integrated transponder tag antennas. Most individuals moved within 500 m (i.e., stationary fish) while 16% of the fish moved > 500 m (i.e., mobile fish), with a maximum median movement distance of 1.89 km and a maximum movement distance of 13.5 km (a long-tail distribution). Most movements occurred near the largest confluence where only a few were long-distance upstream or downstream movements. Mobile fish were larger than their stationary counterparts. Grass Pickerel in sites with higher abundance had more mobile fish, implying potential density dependence. Our results highlight that, while a long-distance dispersal ability exists in extant Grass Pickerel populations, the current conditions of riverscapes may prevent these dispersals from occurring. For declining Grass Pickerel populations, limitations to their movement ecology may substantially increase the likelihood of local extirpations.

RAD‐seq data provide new insights into biogeography, diversity anomaly, and species delimitation in eastern Asian–North American disjunct clade Benthamidia of Cornus (Cornaceae)

AbstractThe big‐bracted dogwood clade Benthamidia of Cornus is a typical example of the well‐known eastern Asia (EA) and North America (NA) floristic disjunction, with greater species diversity in EA than in NA. The lineage provides an opportunity to explore factors contributing to the plant diversity unevenness between EA and NA and test hypotheses on the origin of disjunct distribution from a phylogenetic perspective. We generated RAD‐seq data, conducted phylogenomic and biogeographic analyses for the clade with sampling of all species (9) and subspecies (10) currently recognized in floras. We also assessed species delineation and calculated phylogenetic diversity to evaluate the diversity unevenness between EA and NA. Finally, we examined variation of diversification rates and ecological niches on the phylogeny to explore potential causes underlying the observed diversity pattern. Our results revealed phylogenetic relationships congruent with previous studies and suggested a trans‐Beringian ancestral distribution of the clade Benthamidia in the mid‐Oligocene, dispersal from Mexico to eastern United States in the mid‐Miocene, and early diversification of the EA clade in SW China. Our results also confirmed greater phylogenetic diversity and diversification rate of the EA clade. Species delimitation analysis suggested 17 species in the clade Benthamidia, including all recognized subspecies. By integrating the results of molecular data with morphology, we proposed to retain the subspecies without changing their ranks. Our data suggested increased diversification rate in EA as an intrinsic factor explaining the greater species diversity in the region driven mainly by biogeographic isolation and partially by niche divergence.

Intraspecific phylogeny and genomic resources development for an important medical plant Dioscorea nipponica, based on low-coverage whole genome sequencing data.

Dioscorea nipponica Makino, a perennial twining herb with medicinal importance, has a disjunctive distribution in the Sino-Japanese Floristic Region. It has a long history in traditional Chinese medicine, with demonstrated efficacy against various health conditions. However, the limited genomic data and knowledge of genetic variation have hindered its comprehensive exploration, utilization and conservation. In this study, we undertook low-coverage whole genome sequencing of diverse D. nipponica accessions to develop both plastome (including whole plastome sequences, plastome-derived SSRs and plastome-divergent hotspots) and nuclear genomic resources (including polymorphic nuclear SSRs and single-copy nuclear genes), as well as elucidate the intraspecific phylogeny of this species. Our research revealed 639 plastome-derived SSRs and highlighted six key mutational hotspots (namely CDS ycf1, IGS trnL-rpl32, IGS trnE-trnT, IGS rps16-trnQ, Intron 1 of clpP, and Intron trnG) within these accessions. Besides, three IGS regions (i.e., ndhD-cssA, trnL-rpl32, trnD-trnY), and the intron rps16 were identified as potential markers for distinguishing D. nipponica from its closely related species. In parallel, we successfully developed 988 high-quality candidate polymorphic nuclear SSRs and identified 17 single-copy nuclear genes for D. nipponica, all of which empower us to conduct in-depth investigations into phylogenetics and population genetics of this species. Although our phylogenetic analyses, based on plastome sequences and single-copy nuclear genes revealed cytonuclear discordance within D. nipponica, both findings challenged the current subspecies classification. In summary, this study developed a wealth of genomic resources for D. nipponica and enhanced our understanding of the intraspecific phylogeny of this species, offering valuable insights that can be instrumental in the conservation and strategic utilization of this economically significant plant.

Picking pearls from the Silk Road: Insights into the spider (Arachnida, Araneae) diversity in Georgia from the Caucasus Barcode of life project. Part II

Abstract Spiders collected during field trips and by spontaneous hand collection throughout Georgia between the years 2006 and 2023 were determined to species and partially assisted by genetic barcoding of the COI gene. Among the resulting 297 species, 100 species, 25 genera, and 1 family were recorded from Georgia for the first time, of which 18 species and 5 genera were recorded for the first time from the entire Caucasus. Of the 283 barcoded specimens representing 150 species, 26 were barcoded for the first time. 140 diagnostic drawings of 76 preserved specimens, along with photos of 15 preserved (Supplementary File) and one alive species, are provided. Baryphyma proclive (Simon, 1884), Pritha pallida (Kulczyński, 1897), and Zelotes khostensis Kovblyuk & Ponomarev, 2008 are indicated as the species with an Italo-Caucasian disjunctive distribution.

Lake Superior's summer cooling of shorelines and adjacent inland forests: Implications for refugia of boreal forests and disjunct arctic-alpine plants.

Climate refugia can serve as remnant habitat for cold-adapted species and delay forest transitions. The world's largest freshwater lake by surface area, Lake Superior, serves as a model system for understanding cooling-mediated refugia effects, as its cool summer water temperatures have maintained disjunct populations of arctic-alpine plants on its shoreline since deglaciation. It is known to affect local inland climates by providing a summer cooling effect; however, the inland temperature gradient and spatial patterns of cooling have not been well quantified. Here, we describe the extent, degree, and patterns of temperature buffering and examine drivers of buffering and disjunct plant occurrence for Lake Superior's north shore over a 3-year period at distances of 10, 100 m, 1, 10, and 100 km inland. We analyzed temperature data by year, month, summer maximum (July), and growing degree days (GDD0) for each site. Average summertime cooling at shore sites (10 m) was ~5°C cooler than reference sites (100 km inland), with a maximum difference of -19.2°C. The magnitude of cooling varied geographically, with sites further west and southeast showing little to no cooling effect, while the exposed north-central shore showed the highest degree of buffering (5.8°C cooler) and had a shorter growing season than reference sites. Finally, north-central shorelines had fewer days above 16°C, a threshold above which disjunct plants are unlikely to grow. These sites also showed the highest proportion of disjunct arctic-alpine species, reflecting the highest buffering from inland sites. On north-central shores, sites up to 10 km inland had less than 10 days per year warmer than 20°C, a threshold identified for boreal forest transition. An understanding of the extent of lake-mediated cooling on adjacent forests can better inform the risk to disjunct species, inland forests, and vegetation transition models on Lake Superior's north shore.

Reconstructing the Biogeographic History of the Genus Aurelia Lamarck, 1816 (Cnidaria, Scyphozoa), and Reassessing the Nonindigenous Status of A. solida and A. coerulea in the Mediterranean Sea

The genus Aurelia is one of the most extensively studied within the class Scyphozoa. However, much of the research was historically attributed to the species Aurelia aurita (Linnaeus, 1758) before the recognition of its taxonomic complexity. Initially considered cosmopolitan and globally distributed, recent phylogenetic analysis has challenged this assumption. Consequently, the current distribution of species within the genus Aurelia and the processes that led to this distribution remain largely unexplored. After genetically confirming that the species traditionally present in the Mar Menor coastal lagoon in the southwestern Mediterranean corresponds to A. solida, we compiled data on the locations where moon jellyfish species have been genetically identified and mapped these coordinates to the geological period when the genus Aurelia diverged from other scyphozoan genera. We propose two hypotheses to explain the disjunct distribution of certain species. The first one assumes recent human-mediated introductions, while the second posits an absence of introductions. Both hypotheses, supported by fossil and historical records, suggest a Paleo-Tethys origin of the genus Aurelia. Migration from this area explains most of the genus’s current distribution without human intervention, being the Mediterranean Sea, where A. solida should be considered autochthonous, part of their natural distribution range.

Is Eriocnemis luciani meridae (Aves: Trochilidae) a diagnosable taxon and does it come from Venezuela, with remarks on the collectors Salomn Briceo and Walther Frederick Henninger.

Eriocnemis luciani meridae was originally described from a single specimen collected in the late 19th century in western Venezuela. Subsequently a second specimen of E. luciani, also labelled Venezuela, has been taken as additional proof for a highly disjunct population of this hummingbird, which otherwise ranges from southwest Colombia to southern Peru (taxonomy-dependent). Eriocnemis l. meridae has been accepted by all of the global checklists of birds, but has been routinely ignored by Venezuelan sources. In an effort to resolve this dichotomy of treatment, we re-examined the specimens plumage in comparison with relevant material in two major European bird collections. We found that the characters used to erect E. l. meridae are only doubtfully or weakly expressed in the holotype and appear invisible in the Ohio specimen, but both are clearly referrable to the species E. luciani. Evidence that the second specimen was definitely collected in Venezuela is weak and its overall provenance is unclear. In contrast, an extensive historical investigation of the relevant collectors indicates that the holotype does appear to have been taken in Venezuela, although perhaps not in the precise locality indicated for it. This leaves an unusual situation whereby we consider the case for a separate Venezuelan endemic taxon to be unproven, but there is no incontrovertible reason to exclude the species from the countrys avifauna; according to recent niche modelling data it is best searched for in the Sierra Nevada of Mrida state. In contrast, a second subspecies of E. luciani, E. l. baptistae, described by the same authors as endemic to part of western Ecuador is, according to our reappraisal, clearly diagnosable and is upheld.

Inter-colony variation in predation, mercury burden and adult survival in a declining seabird

Migratory species with disjunct and localized breeding distributions, including many colonial marine birds, pose challenges for management and conservation as their dynamics are shaped by both broad oceanographic changes and specific factors affecting individual breeding colonies. We compare six colonies of the declining Leach's storm-petrel, Hydrobates leucorhous, across their core range in Atlantic Canada using standard capture-mark-recapture methods to estimate annual survival of individually marked populations of breeding adults. Over the period analysed (5–20 years per colony; 2003–2022), mean annual survival varied among colonies (0.81–0.88) and annually (process error σ ranging from 0.01 to 0.09), though annual fluctuations were not synchronous across colonies. Two colonies with limited natural predation showed higher survival, and there was a decline in survival with increasing colony-specific total mercury burden. Our work shows that colony-specific pressures and regional contaminant burdens are potentially important contributors to current population declines, and highlights the importance of monitoring demographic rates at multiple sites for species that congregate at key life-history stages.