Insufficient and biased representation of species geographic responses to climate change.

The geographic redistributions of species due to a rapidly changing climate are poised to perturb ecological communities and significantly impact ecosystems and human livelihoods. Effectively managing these biological impacts requires a thorough understanding of the patterns and processes of species geographic range shifts. While substantial recent redistributions have been identified and recognized to vary by taxon, region, and range geometry, there are large gaps and biases in the available evidence. Here, we use the largest compilation of geographic range change observations to date, comprised of 33,016 potential redistributions across 12,009 species, to formally assess within- and cross-species coverage and biases and to motivate future data collection. We find that species coverage varies strongly by taxon and underrepresents species at high and low latitudes. Within species, assessments of potential redistributions came from parts of their geographic range that were highly uneven and non-representative. For most species and taxa, studies were strongly biased toward the colder parts of species' distributions and thus significantly underrepresented populations that might get pushed beyond their maximum temperature limits. Coverage of potential leading and trailing geographic range edges under a changing climate was similarly uneven. Only 8% of studied species were assessed at both high and low latitude and elevation range edges, with most only covered at one edge. This suggests that substantial within-species biases exacerbate the considerable geographic and taxonomic among-species unevenness in evidence. Our results open the door for a more quantitative accounting for existing knowledge biases in climate change ecology and a more informed management and conservation. Our findings offer guidance for future data collection that better addresses information gaps and provides a more effective foundation for managing the biological impacts of climate change.

Flexibility in thermal requirements: a comparative analysis of the wide-spread lizard genus Sceloporus.

Adaptation or acclimation of thermal requirements to environmental conditions can reduce thermoregulation costs and increase fitness, especially in ectotherms, which rely heavily on environmental temperatures for thermoregulation. Insight into how thermal niches have shaped thermal requirements across evolutionary history may help predict the survival of species during climate change. The lizard genus Sceloporus has a widespread distribution and inhabits an ample variety of habitats. We evaluated the effects of geographical gradients (i.e. elevation and latitude) and local environmental temperatures on thermal requirements (i.e. preferred body temperature, active body temperature in the field, and critical thermal limits) of Sceloporus species using published and field-collected data and performing phylogenetic comparative analyses. To contrast macro- and micro-evolutional patterns, we also performed intra-specific analyses when sufficient reports existed for a species. We found that preferred body temperature increased with elevation, whereas body temperature in the field decreased with elevation and increased with local environmental temperatures. Critical thermal limits were not related to the geographic gradient or environmental temperatures. The apparent lack of relation of thermal requirements to geographic gradient may increase vulnerability to extinction due to climate change. However, local and temporal variations in thermal landscape determine thermoregulation opportunities and may not be well represented by geographic gradient and mean environmental temperatures. Results showed that Sceloporus lizards are excellent thermoregulators, have wide thermal tolerance ranges, and the preferred temperature was labile. Our results suggest that Sceloporus lizards can adjust to different thermal landscapes, highlighting opportunities for continuous survival in changing thermal environments.

The decline and fall of the mammalian stem.

The mammalian crown originated during the Mesozoic and subsequently radiated into the substantial array of forms now extant. However, for about 100 million years before the crown's origin, a diverse array of stem mammalian lineages dominated terrestrial ecosystems. Several of these stem lineages overlapped temporally and geographically with the crown mammals during the Mesozoic, but by the end of the Cretaceous crown mammals make up the overwhelming majority of the fossil record. The progress of this transition between ecosystems dominated by stem mammals and those dominated by crown mammals is not entirely clear, in part due to a distinct separation of analyses and datasets. Analyses of macroevolutionary patterns tend to focus on either the Mammaliaformes or the non-mammalian cynodonts, with little overlap in the datasets, preventing direct comparison of the diversification trends. Here I analyse species richness and biogeography of Synapsida as a whole during the Mesozoic, allowing comparison of the patterns in the mammalian crown and stem within a single framework. The analysis reveals the decline of the stem mammals occurred in two discrete phases. The first phase occurred between the Triassic and Middle Jurassic, during which the stem mammals were more restricted in their geographic range than the crown mammals, although within localities their species richness remained at levels seen previously. The second phase was a decline in species richness, which occurred during the Lower Cretaceous. The results show the decline of stem mammals, including tritylodontids and several mammaliaform groups, was not tied to a specific event, nor a gradual decline, but was instead a multiphase transition.

The global distribution of angiosperm genome size is shaped by climate.

Angiosperms, which inhabit diverse environments across all continents, exhibit significant variation in genome sizes, making them an excellent model system for examining hypotheses about the global distribution of genome size. These include the previously proposed large genome constraint, mutational hazard, polyploidy-mediated, and climate-mediated hypotheses. We compiled the largest genome size dataset to date, encompassing 16 017 (> 5% of known) angiosperm species, and analyzed genome size distribution using a comprehensive geographic distribution dataset for all angiosperms. We observed that angiosperms with large range sizes generally had small genomes, supporting the large genome constraint hypothesis. Climate was shown to exert a strong influence on genome size distribution along the global latitudinal gradient, while the frequency of polyploidy and the type of growth form had negligible effects. In contrast to the unimodal patterns along the global latitudinal gradient shown by plant size traits and polyploid proportions, the increase in angiosperm genome size from the equator to 40-50°N/S is probably mediated by different (mostly climatic) mechanisms than the decrease in genome sizes observed from 40 to 50°N northward. Our analysis suggests that the global distribution of genome sizes in angiosperms is mainly shaped by climatically mediated purifying selection, genetic drift, relaxed selection, and environmental filtering.

One hundred and six years of change in a Sonoran Desert plant community: Impact of climate anomalies and trends in species sensitivities.

A major restriction in predicting plant community response to future climate change is a lack of long-term data needed to properly assess species and community response to climate and identify a baseline to detect climate anomalies. Here, we use a 106-year dataset on a Sonoran Desert plant community to test the role of extreme temperature and precipitation anomalies on community dynamics at the decadal scale and over time. Additionally, we tested the climate sensitivity of 39 desert plant species and whether sensitivity was associated with growth form, longevity, geographic range, or local dominance. We found that desert plant communities had shifted directionally over the 106 years, but the climate had little influence on this directional change primarily due to nonlinear shifts in precipitation anomalies. Decadal-scale climate had the largest impact on species richness, species relative density, and total plant cover, explaining up to 26%, 45%, and 55% of the variance in each, respectively. Drought and the interaction between the frequency of freeze events and above-average summer precipitation were among the most influential climate factors. Increased drought frequency and wetter periods with frequent freeze events led to larger reductions in total plant cover, species richness, and the relative densities of dominant subshrubs Ambrosia deltoidea and Encelia farinosa. More than 80% of the tested species were sensitive to climate, but sensitivity was not associated with a species' local dominance, longevity, geographic range, or growth form. Some species appear to exhibit demographic buffering, where when they have a higher sensitivity to drought, they also tend to have a higher sensitivity to favorable (i.e., wetter and hotter) conditions. Overall, our results suggest that, while decadal-scale climate variation substantially impacts these desert plant communities, directional change in temperature over the last century has had little impact due to the relative importance of precipitation and drought. With projections of increased drought in this region, we may see reductions in total vegetation cover and species richness due to the loss of species, possibly through a breakdown in their ability to demographically buffer climatic variation, potentially changing community dynamics through a change in facilitative and competitive processes.

Built for success: Distribution, morphology, ecology and life history of the world's skinks.

In animals, the success of particular lineages can be measured in terms of their number of species, the extent of their geographic range, the breadth of their habitats and ecological niches, and the diversity of their morphological and life-history traits. Here, we review the distribution, ecology, morphology and life history of skinks, a diverse lineage of terrestrial vertebrates. We compared key traits between the three subfamilies of skinks, and between skinks and non-scincid lizards. There are currently 1743 described species of skink, which represent 24% of global lizard diversity. Since 2010, 16% of lizard descriptions have been of skinks. The centres of skink diversity are in Australia, New Guinea, southeast Asia, Oceania, Madagascar and central Africa. Compared with non-scincid lizards, skinks have larger distributional ranges, but smaller body sizes. Sexual size dimorphism is rare in skinks. Almost a quarter (23%) of skinks exhibit limb reduction or loss, compared with just 3% of non-scincid lizards. Skinks are more likely to be viviparous (34% of species) compared with non-scincids (13%), and have higher clutch/litter sizes than non-scincids. Although skinks mature later than non-scincids, their longevity is similar to that exhibited by other lizard groups. Most skinks (88%) are active foragers, and they are more likely to be carnivorous than non-scincids. Skinks are more likely to be diurnal or cathemeral than other lizard groups, but they generally have lower field body temperatures compared with non-scincids. The success of skinks appears to be both a result of them hitting upon a winning body plan and ecology, and their capacity to regularly deviate from this body plan and adapt their ecology and life history (e.g. repeated limb reduction and loss, transitions to viviparity) to prevailing conditions.

The Perspective of Arctic-Alpine Species in Southernmost Localities: The Example of Kalmia procumbens in the Pyrenees and Carpathians.

High-mountain and arctic plants are considered especially sensitive to climate change because of their close adaptation to the cold environment. Kalmia procumbens, a typical arctic-alpine species, reaches southernmost European localities in the Pyrenees and Carpathians. The aim of this study was the assessment and comparison of the current potential niche areas of K. procumbens in the Pyrenees and Carpathians and their possible reduction due to climate change, depending on the scenario. The realized niches of K. procumbens in the Pyrenees are compact, while those in the Carpathians are dispersed. In both mountain chains, the species occurs in the alpine and subalpine vegetation belts, going down to elevations of about 1500-1600 m, while the most elevated localities in the Pyrenees are at ca. 3000 m, about 500 m higher than those in the Carpathians. The localities of K. procumbens in the Carpathians have a more continental climate than those in the Pyrenees, with lower precipitation and temperatures but higher seasonality of temperature and precipitation. The species covered a larger area of geographic range during the Last Glacial Maximum, but its geographic range was reduced during the mid-Holocene. Due to climate warming, a reduction in the potential area of occurrence could be expected in 2100; this reduction is expected to be strong in the Carpathians and moderate in the Pyrenees.

Species-level correlates of land-use responses and climate-change sensitivity in terrestrial vertebrates.

Land-use and climate change are major pressures on terrestrial biodiversity. Species' extinction risk and responses to human pressures relate to ecological traits and other characteristics in some clades. However, large-scale comparative assessments of the associations between traits and responses to multiple human pressures across multiple clades are needed. We investigated whether a set of ecological characteristics that are commonly measured across terrestrial vertebrates (ecological traits and geographic range area) are associated with species' responses to different land-use types and species' likely sensitivity to climate change. We aimed to test whether generalizable patterns in response to these pressures arise across both pressures and across vertebrate clades, which could inform assessments of the global signature of human pressures on vertebrate biodiversity and guide conservation efforts. At the species level, we investigated associations between land-use responses and ecological characteristics with a space-for-time substitution approach, making use of the PREDICTS database. We investigated associations between ecological characteristics and expected climate-change sensitivity, estimated from properties of species realized climatic niches. Among the characteristics we considered, 3 were consistently associated with strong land-use responses and high climate-change sensitivity across terrestrial vertebrate classes: narrow geographic range, narrow habitat breadth, and specialization on natural habitats (which described whether a species occurs in artificial habitats or not). The associations of other traits with species' land-use responses and climate-change sensitivity often depended on species' class and land-use type, highlighting an important degree of context dependency. In all classes, invertebrate eaters and fruit and nectar eaters tended to be negatively affected in disturbed land-use types, whereas invertebrate-eating and plant- and seed-eating birds were estimated to be more sensitive to climate change, raising concerns about the continuation of ecological processes sustained by these species under global changes. Our results highlight a consistently higher sensitivity of narrowly distributed species and habitat specialists to land-use and climate change, which provides support for capturing such characteristics in large-scale vulnerability assessments.

Correlaciones a nivel de especie de las respuestas al uso de suelo y la susceptibilidad al cambio climático en los vertebrados terrestres Resumen El uso de suelo y el cambio climático tienen una presión importante sobre la biodiversidad terrestre. En algunos clados, el riesgo de extinción de las especies y las respuestas a las presiones humanas se relacionan con los rasgos ecológicos y otras características. Sin embargo, varios clados necesitan evaluaciones comparativas a gran escala de las asociaciones entre los rasgos y las respuestas a las presiones humanas. Investigamos si un conjunto de rasgos ecológicos medidos comúnmente en los vertebrados terrestres (rasgos ecológicos y extensión del área geográfica) está asociado con la respuesta de las especies a los diferentes tipos de uso de suelo y la posible susceptibilidad de la especie al cambio climático. Buscamos comprobar si los patrones generalizables de las respuestas a estas presiones surgen en ambas presiones y en todos los clados de vertebrados, lo que podría guiar las evaluaciones de la huella mundial de presiones humanas sobre la diversidad de vertebrados y los esfuerzos de conservación. Investigamos las asociaciones entre la respuesta al uso de suelo y los rasgos ecológicos a nivel de especie con una estrategia de reemplazo de espacio por tiempo y con información de la base de datos PREDICTS. También investigamos las asociaciones entre los rasgos ecológicos y la susceptibilidad al cambio climático esperada, la cual estimamos a partir de las propiedades de los nichos climáticos de las especies. Entre las características que consideramos, tres estuvieron asociadas de manera regular con respuestas fuertes al uso de suelo y alta susceptibilidad al cambio climático en las diferentes clases de vertebrados: la extensión geográfica limitada, la amplitud reducida de hábitat y la especialización en los hábitats naturales (la cual describe si una especie está presente en un hábitat artificial o no). Las asociaciones de otros rasgos con la respuesta de la especie al uso de suelo y su susceptibilidad al cambio climático con frecuencia dependieron de la clase de la especie y el tipo de uso de suelo, lo que resalta un grado importante de dependencia del contexto. En todas las clases, los frugívoros, nectarívoros y los que comen invertebrados eran propensos a sufrir efectos negativos en los usos de suelo de tipo perturbado, mientras que se estimó que las aves herbívoras, las que se alimentan de semillas y las que se alimentan de invertebrados eran más susceptibles al cambio climático, lo que incrementa la preocupación por la continuación de los procesos ecológicos que viven estas especies bajo los cambios globales. Nuestros resultados resaltan una susceptibilidad al uso de suelo y al cambio climático cada vez mayor en las especies con distribución limitada y las especialistas de hábitat, lo que proporciona un respaldo para la captura de dichas características en las evaluaciones a gran escala de la vulnerabilidad.

The first large-scale record of gelada's spatial distribution and population size in Mountain chains of Tigray, Northern Ethiopia.

Gelada (Theropithecus gelada) is an Ethiopian endemic mammal whose range was previously believed to be limited to the Bale and Simien Mountain national parks. However, knowledge of the range of the species is still not satisfactory. This study was designed to investigate the distribution and population size of the gelada in selected highlands in Tigray. To achieve this, study areas were divided into census tracts identified for a direct field assessment using habitat-based counting approaches. Moreover, informal interviews were conducted parallel to the direct field assessment in different villages. Our large spatial scale survey, the first of its kind for the region, confirmed the presence of T. gelada in three mountain clusters in Tigray for the first time. A total of 223 individual geladas were recorded in Ganta Afeshum, Hawzen and Welkait escarpments. The highest number of individuals (35.7 ± 3.8) was recorded in Hawzen (with 6.99 individuals/km2), followed by Ganta Afeshum (with 4.3 individuals/km2). Agricultural expansion, settlement and a lack of community awareness are the key threats operating against the conservation of the gelada in its current range in Tigray. Further research on the overall ecology, feeding, and spatial distribution of the species should be projected.

Global biodiversity data suggest allopolyploid plants do not occupy larger ranges or harsher conditions compared with their progenitors.

Understanding the factors determining species' geographical and environmental range is a central question in evolution and ecology, and key for developing conservation and management practices. Shortly after the discovery of polyploidy, just over 100 years ago, it was suggested that polyploids generally have greater range sizes and occur in more extreme conditions than their diploid congeners. This suggestion is now widely accepted in the literature and is attributed to polyploids having an increased capacity for genetic diversity that increases their potential for adaptation and invasiveness. However, the data supporting this idea are mixed. Here, we compare the niche of allopolyploid plants to their progenitor species to determine whether allopolyploidization is associated with increased geographic range or extreme environmental tolerance. Our analysis includes 123 allopolyploid species that exist as only one known ploidy level, with at least one known progenitor species, and at least 50 records in the Global Biodiversity Information Facility (GBIF) database. We used GBIF occurrence data and range modeling tools to quantify the geographic and environmental distribution of these allopolyploids relative to their progenitors. We find no indication that allopolyploid plants occupy more extreme conditions or larger geographic ranges than their progenitors. Data evaluated here generally indicate no significant difference in range between allopolyploids and progenitors, and where significant differences do occur, the progenitors are more likely to exist in extreme conditions. We concluded that the evidence from these data indicate allopolyploidization does not result in larger or more extreme ranges. Thus, allopolyploidization does not have a consistent effect on species distribution, and we conclude it is more likely the content of an allopolyploid's genome rather than polyploidy per se that determines the potential for invasiveness.

Sustained mangrove reproduction despite major turnover in pollinator community composition at expanding range edge.

BACKGROUND AND AIMS: How well plants reproduce near their geographic range edge can determine whether distributions will shift in response to changing climate. Reproduction at the range edge can be limiting if pollinator scarcity leads to pollen limitation, or if abiotic stressors affect allocation to reproduction. For many animal-pollinated plants with expanding ranges, the mechanisms by which they have overcome these barriers are poorly understood. METHODS: In this study, we examined plant-pollinator interactions hypothesized to impact reproduction of the black mangrove, Avicennia germinans, which is expanding northward in coastal Florida, USA. We monitored insects visiting A. germinans populations varying in proximity to the geographic range edge, measured the pollen loads of the most common insect taxa and pollen receipt by A. germinans stigmas, and quantified flower and propagule production. KEY RESULTS: We found that despite an 84 % decline in median floral visits by insects at northernmost versus southernmost sites, range-edge pollen receipt remained high. Notably, local floral visitor assemblages exhibited substantial turnover along the study's latitudinal gradient, with large-bodied bees and hover flies increasingly common at northern sites. We also observed elevated flower production in northern populations and higher per capita reproductive output at the range edge. Furthermore, mean propagule mass in northern populations was 18 % larger than that from the southernmost populations. CONCLUSIONS: These findings reveal no erosion of fecundity in A. germinans populations at range limits, allowing rapid expansion of mangrove cover in the region. These results also illustrate that substantial turnover in the assemblage of flower-visiting insects can occur at an expanding range edge without altering pollen receipt.

Plant Species' Capacity for Range Shifts at the Habitat and Geographic Scales: A Trade-Off-Based Framework.

Climate change is causing rapid shifts in the abiotic and biotic environmental conditions experienced by plant populations, but we lack generalizable frameworks for predicting the consequences for species. These changes may cause individuals to become poorly matched to their environments, potentially inducing shifts in the distributions of populations and altering species' habitat and geographic ranges. We present a trade-off-based framework for understanding and predicting whether plant species may undergo range shifts, based on ecological strategies defined by functional trait variation. We define a species' capacity for undergoing range shifts as the product of its colonization ability and the ability to express a phenotype well-suited to the environment across life stages (phenotype-environment matching), which are both strongly influenced by a species' ecological strategy and unavoidable trade-offs in function. While numerous strategies may be successful in an environment, severe phenotype-environment mismatches result in habitat filtering: propagules reach a site but cannot establish there. Operating within individuals and populations, these processes will affect species' habitat ranges at small scales, and aggregated across populations, will determine whether species track climatic changes and undergo geographic range shifts. This trade-off-based framework can provide a conceptual basis for species distribution models that are generalizable across plant species, aiding in the prediction of shifts in plant species' ranges in response to climate change.

The 2021 emergence of Brood X periodical cicadas Magicicada spp. (Hemiptera: Cicadidae) in Georgia, United States of America.

The US state of Georgia includes the range of several periodical cicada broods and is the southernmost state in which Brood X periodical cicadas emerge; however, no research has focused on this brood in this state. We used reports of sightings on social media, communication with the public, and our own searches to determine the geographic range in Georgia and timing of biological events. Both adults and exuviae were identified to species to determine the species makeup at those locations. The first Brood X adult was photographed on April 26 in Lumpkin County, and Magicicada septendecim L. was the most common species. Online records and site visits led to distribution records in nine counties, including six that provided no records in the 2004 emergence. Driving surveys revealed patchy distributions of chorusing adults and species distribution modeling further predicted locations where Brood X can be found in future surveys. We observed cicada oviposition scars at two locations and found no effect of host plant on presence or density of scars. Lastly, collections of dead adults showed female remains were less common and more likely to be dismembered. Further investigations of the periodical cicadas in Georgia are recommended to better understand the phenology, evolution, and ecology of these remarkable insects.

Latitudinal gradients in body size and sexual size dimorphism in fleas: males drive Bergmann's pattern.

We tested for the effects of latitude and geographic range size (GRS) on body size, leg length, and sexual size dimorphism (SSD) across 103 species of fleas, taking into account phylogenetic between-species relationships. When the data on body size were combined for males and females, the positive correlation between body size and latitude, but not GRS, was revealed. When the analysis was restricted to one sex only, the effect of latitude appeared to be non-significant for females, whereas male body size increased with an increase in latitude. Intraspecific body size variation was not associated with either the latitude or the latitudinal span of the geographic range, independently of which data subset was analyzed. No evidence of association between size-independent tibia length and latitude was found for either females, males, or both sexes combined. The degree of SSD decreased with a decrease in latitude but was not affected by GRS. We conclude that macroecological patterns might be manifested differently in males and females. This should be kept in mind while searching for these patterns.

Scale of population synchrony confirms macroecological estimates of minimum viable range size.

Global ecosystems are facing a deepening biodiversity crisis, necessitating robust approaches to quantifying species extinction risk. The lower limit of the macroecological relationship between species range and body size has long been hypothesized as an estimate of the relationship between the minimum viable range size (MVRS) needed for species persistence and the organismal traits that affect space and resource requirements. Here, we perform the first explicit test of this assumption by confronting the MVRS predicted by the range-body size relationship with an independent estimate based on the scale of synchrony in abundance among spatially separated populations of riverine fish. We provide clear evidence of a positive relationship between the scale of synchrony and species body size, and strong support for the MVRS set by the lower limit of the range-body size macroecological relationship. This MVRS may help prioritize first evaluations for unassessed or data-deficient taxa in global conservation assessments.

Geographic range size, water temperature, and extrinsic threats predict the extinction risk in global cetaceans.

Despite the fact that cetaceans provide significant ecological contributions to the health and stability of aquatic ecosystems, many are highly endangered with nearly one-third of species assessed as threatened with extinction. Nevertheless, to date, few studies have explicitly examined the patterns and processes of extinction risk and threats for this taxon, and even less between the two subclades (Mysticeti and Odontoceti). To fill this gap, we compiled a dataset of six intrinsic traits (active region, geographic range size, body weight, diving depth, school size, and reproductive cycle), six environmental factors relating to sea surface temperature and chlorophyll concentration, and two human-related threat indices that are commonly recognized for cetaceans. We then employed phylogenetic generalized least squares models and model selection to identify the key predictors of extinction risk in all cetaceans, as well as in the two subclades. We found that geographic range size, sea surface temperature, and human threat index were the most important predictors of extinction risk in all cetaceans and in odontocetes. Interestingly, maximum body weight was positively associated with the extinction risk in mysticetes, but negatively related to that for odontocetes. By linking seven major threat types to extinction risk, we further revealed that fisheries bycatch was the most common threat, yet the impacts of certain threats could be overestimated when considering all species rather than just threatened ones. Overall, we suggest that conservation efforts should focus on small-ranged cetaceans and species living in warmer waters or under strong anthropogenic pressures. Moreover, further studies should consider the threatened status of species when superimposing risk maps and quantifying risk severity. Finally, we emphasize that mysticetes and odontocetes should be conserved with different strategies, because their extinction risk patterns and major threat types are considerably different. For instance, large-bodied mysticetes and small-ranged odontocetes require special conservation priority.

Fish-parasite interactions: A dataset of continental waters in Mexico involving fishes and their helminth fauna.

Most of the available knowledge in the literature on Mexican fishes and their parasites refers to information within political divisions and/or hydrological basins in the country. Indeed, only a few studies have analyzed the helminth fauna of these vertebrates as a biological group distributed nation-wide. This lack of available knowledge prevents the study of several basic and applied aspects involving fish-parasite interactions at different spatial and temporal scales. In this dataset, we compiled all the available geographic information on fish-helminth parasite interactions involving native and exotic fish species recorded in continental waters throughout the Mexican territory. After an exhaustive filtering and the curation of information, our data set contains 5999 records of 361 freshwater fish species (roughly 70% of known freshwater fish species occurring in Mexico) and 483 endo- and ectoparasitic helminths collected over an 85-year period (from 1936-2021) in 1070 localities distributed throughout Mexico. These records are mainly concentrated in only a few states located to the south and east of the country; although all states have been sampled and all major basins in Mexico are represented. The fish order with the highest number of records was Perciformes (n = 2325, 38.75%) while the fish family with the highest number of records was Cichlidae (n = 1741, 29.02%). Native species of fishes corresponded to 92.14% of the records (n = 5528) and fish-associated parasites were found in 41 habitat types in/on their host bodies. Regarding fish parasites, we found that most of the records are from the phylum Platyhelminthes (n = 4495, 74.92%). At the class level, we observed that Trematoda reached the highest number of records (n = 2965, 49.42%). Moreover, we found that Diplostomidae (n = 917, 15.25%) were the family of trematodes with the highest number of records. Most parasites were registered in their adult stage (n = 3730, 62.17%), followed by larval stages (n = 2267, 37.78%). We hope that the fish-parasite interactions data set will encourage researchers worldwide to explore different ecological and coevolutionary aspects of fishes and their helminth parasites, as well as provide useful information for the better implementation of conservation initiatives. There are no copyright restrictions; please cite this data paper when using its data in publications or teaching events.

Integrating geographic ranges across temporal scales.

Geographic ranges are a fundamental unit of biogeography and macroecology. Increasingly, paleontologists and ecologists alike are reconstructing geographic ranges of species from fossils, in order to understand the long-term processes governing biogeographic and macroevolutionary patterns. As these reconstructions have become increasingly common, uncertainty has arisen over the equivalency of paleo-ranges and modern ranges. Here, we argue geographic ranges are time-averaged at all temporal scales, and reflect the biotic and abiotic processes operating across the equivalent range of time and space scales. This conceptual framework integrates the study of geographic ranges reconstructed using modern and ancient data, and highlights the potential for ranges to illuminate processes responsible for diversity patterns over intervals spanning days to tens of millions of years of Earth history.

Effects of occupancy estimation on abundance-occupancy relationships.

Abundance-occupancy relationships predict that species that occupy more sites are also more locally abundant, where occupancy is usually estimated following the assumption that species can occupy all sampled sites. Here we use the National Ecological Observatory Network small-mammal data to assess whether this assumption affects abundance-occupancy relationships. We estimated occupancy considering all sampled sites (traditional occupancy) and only the sites found within the species geographic range (spatial occupancy) and realized environmental niche (environmental occupancy). We found that when occupancy was estimated considering only sites possible for the species to colonize (spatial and environmental occupancy) weaker abundance-occupancy relationships were observed. This shows that the assumption that the species can occupy all sampled sites directly affects the assessment of abundance-occupancy relationships. Estimating occupancy considering only sites that are possible for the species to colonize will consequently lead to a more robust assessment of abundance-occupancy relationships.