Science Enabled by Specimen Data

Owen, E., M. Zuliani, M. Goldgisser, and C. Lortie. 2024. The importance of native shrubs on the distribution and diversity of reptiles and amphibians in the central drylands of Southwestern USA. Biodiversity and Conservation 33: 2131–2151. https://doi.org/10.1007/s10531-024-02851-8

Conservation and management of drylands is a global challenge. Key attributes of these ecosystems, such as dominant vegetation including shrubs, can provide a crucial mechanism to inform conservation strategies. The shrub species Ephedra californica and Larrea tridentata are common native shrub species within the deserts of California and frequently benefit other plant and animal species. Here, we tested the hypothesis that shrubs support reptile and amphibian communities through relative increases in available habitat, estimated through increasing shrub densities at the site level. Reported occurrence data from the Global Biodiversity Information Facility (GBIF) and high-resolution satellite images were used to test for local-to-regional patterns in reptile and amphibian distribution and diversity by shrub densities at sites. At 43 distinct sites, the relationship between shrub density and reported reptile and amphibian communities was also tested. A total of 71 reptile and amphibian species were reported regionally. Increases in shrub density across sites positively influenced the relative abundance and richness of reptiles and amphibians observed. Moreover, increasing shrub density also had a positive influence on species evenness. Aridity differences between sites did not significantly influence the relationship between shrub density and reptiles and amphibians suggesting that the relationship was robust. This study highlights the importance of foundational shrub species in supporting reptile and amphibian communities in arid and semi-arid regions. Large-scale patterns of biodiversity in deserts can be supported by positive plant-animal interactions including small islands of fertility and resources for animals in the context of a warming climate.

Garcia-Cardenas, E. E., L. E. Angeles-Gonzalez, and G. Alcaraz. 2024. Hermit crabs of the genera Calcinus and Clibanarius show no evidence of competitive exclusion at a geographic scale. Hydrobiologia. https://doi.org/10.1007/s10750-024-05501-w

The fundamental ecological niche is determined by individuals’ ability to cope with abiotic conditions; however, biotic interactions (e.g., competition) can also influence species’ distribution ranges, reducing the fundamental niche to the realized niche. Several species of the genera Clibanarius and Calcinus overlap in their distributions. The agonistically dominant Calcinus species inhabits mostly lower intertidal levels, while Clibanarius is more abundant in the abiotically demanding upper strata. Additionally, evidence of microhabitat competitive exclusion shows that the superior competitor, Ca . californiensis , causes the vertical displacement of Cl . albidigitus . However, it is unknown whether competitive exclusion between species of these genera has influenced their distributions at the macroecological scale. We used ecological niche models to compare the distribution and the habitat suitability of species of these genera. We used databases of species occurrences and bioclimatic and geophysical variables to model and map the species’ niches. Species of the two hermit crab genera showed strong overlap in their habitat suitability. Calcinus and Clibanarius species occur in broad sympatry at the regional scale without regions of partial overlap that would indicate competitive exclusion. Therefore, competitive exclusion among species of these genera seems to act only on a microhabitat scale in the most dynamic shoreline areas.

Belotti López de Medina, C. R. 2024. Diet breadth and biodiversity in the pre-hispanic South-Central Andes (Western South America) during the Holocene: An exploratory analysis and review. The Holocene. https://doi.org/10.1177/09596836241231446

This paper presents an exploratory study on the taxonomic diversity of pre-Hispanic archaeofaunas in the South-Central Andes (SCA; western South America) from the Pleistocene-Holocene boundary to the Late-Holocene. The SCA is a complex of diverse environments and has undergone distinct climate events for the last 13,000 years, such as the occurrence of warmer and drier conditions in the Middle-Holocene. The South-Central Andean area was part of the larger Andes interaction area, which was a primary center for animal and plant domestication and the emergence of agro-pastoralist economies. Since subsistence was key to these processes, the SCA provides a relevant case study on the interactions among environment, foodways and sociocultural evolution. Taxonomic diversity was used here as a proxy for diet breadth. A total of 268 archaeofaunal assemblages were sampled from the zooarchaeological literature. Reviewed variables included the cultural chronology and spatial coordinates of the assemblages, as well as the presence and abundance of taxa at the family rank. Taxonomic diversity covered two dimensions: composition (families present in each assemblage) and structure (quantitative relationships among taxa), which was measured through richness (NTAXA), ubiquity and relative abundance (NISP based rank-order). Despite the uneven distribution of samples, the analyses revealed the following trends: (1) a moderate relationship between NTAXA and distance from coastline for most of the Holocene; (2) a potential decrease in assemblage richness for coastal ecoregions during the Late-Holocene; and (3) a generalized increase in the relative abundance of Camelidae.

Di Salvatore, P., M. J. Albano, M. J. Diez, F. Tapella, P. Pérez-Barros, and G. A. Lovrich. 2023. Decapods of the Southern Tip of South America and the Marine Protected Area Namuncurá–Burdwood Bank: A Nearshore–Offshore Comparison. Diversity 15: 1143. https://doi.org/10.3390/d15111143

The Marine Protected Area (MPA) Namuncurá−Burdwood Bank was created in 2013 to protect the benthic community. After five years of multidisciplinary research, it was reorganized, and a second, contiguous MPA Namuncurá−Burdwood Bank II was created. The objectives of this study were to evaluate the decapod assemblages in both the previous and current management zones and to compare them with the neighboring areas of southern South America. The decapod fauna was studied integratively by comparing captured species onboard scientific expeditions with online records. Our study showed that the original design of the MPAN−BB had the lowest decapod species richness. However, the constitution of a larger protected area, including the slope, increased the species richness, with unique records of Campylonotus arntzianus and Lithodes couesi. The MPA could be considered ecologically representative as it shares various species with the nearby areas (the Beagle Channel and the Atlantic). Furthermore, we theorize it could act as a “hub” for decapod species as marine currents provide the Burdwood Bank with new individuals from the west and disperse them northward to the Patagonian Shelf and eastward to the Scotia Arc. This result shows the great value of protecting this area, ensuring the conservation of the decapod fauna of southern South America.

Herrera, D. L., S. A. Navarrete, F. A. Labra, S. P. Castillo, and L. Opazo Mella. 2023. Functional biogeography of coastal marine invertebrates along the south‐eastern Pacific coast reveals latitudinally divergent drivers of taxonomic versus functional diversity. Ecography. https://doi.org/10.1111/ecog.06476

Characterizing the spatial structure of taxonomic and functional diversity (FD) of marine organisms across regional and latitudinal scales is essential for improving our understanding of the processes driving species richness and those that may constrain or enhance the set of species traits that define the functional structure of communities. Here, we present the functional diversity of coastal invertebrate macrofaunal species along the south‐eastern Pacific from 7°N to 56°S, describe spatial variation of species traits, and examine the relationship with environmental variables. For that, we defined the functional traits and distribution ranges of 2350 marine macroinvertebrates calculated eight metrics of FD. Random forest regression was applied to identify significant relationships between FD and six environmental variables. Finally, functional β‐turnover was estimated to detect alongshore shifts in functional structure and their coincidence with biogeographical domains. Our results show, in contrast with taxonomic richness that measures of trait differences, functional space and functional specialisation increase with latitude, while functional evenness exhibits a non‐linear shape, peaking at mid latitudes. Functional redundancy decreased significantly poleward, while indicators of vulnerability increase. In contrast to taxonomic richness, FD was tightly connected to variables indicative of stress and productivity, such as dissolved oxygen and nutrients. Sea surface temperature and coastal area best explained the increased FD redundancy and richness towards the tropics. The high spatial correlation between taxonomic and functional turnover suggests environmental filters play an important role in the functional structure of the seascape. Our findings suggest that processes favouring taxonomic richness are latitudinally divergent from those favouring functional diversity. Correlations with environmental variables suggest that increased sea surface temperature and measures of stability increase redundancy, while variations in dissolved oxygen and nutrients positively affect functional diversification. Moreover, the functional diversity patterns suggest low resilience of high latitude coastal ecosystems, which are heavily exploited and threatened by climate change, hence highlighting the urgent need for effective conservation policies.

García-Navarrete, P. G., L. A. Sánchez-González, and J. J. Morrone. 2023. Biogeographical affinities of the biota of the Tres Marías Islands, Mexico. Biological Journal of the Linnean Society. https://doi.org/10.1093/biolinnean/blad101

The Tres Marías archipelago in the central Mexican Pacific is a protected area that has a complex geological history due to its tectonic setting. This study describes an integrative analysis of the biogeographical affinities of the biota inhabiting the islands. A biotic component analysis showed a close relationship between the islands and the Pacific Lowlands and Veracruzan biogeographical provinces, whereas a cladistic biogeographical analysis additionally showed a Nearctic affinity with the Sonoran biogeographical province. The biogeographical affinity patterns, based on the distribution of the sister group of each endemic species, revealed three distinct patterns: Neotropical, Sonoran-Neotropical and Nearctic-Neotropical. The study recognized that the Tres Marías Islands are a region of great biological complexity where the biota of the Pacific Lowlands and the Veracruzan provinces intersect, with a predominantly Neotropical affinity. In this biogeographical analysis, information on the biotic assemblage and the geological history of the Tres Marías Islands are integrated and discussed. The biotic assembly of the islands must have occurred via both vicariance and dispersal at different geological times, related to opening of the Gulf of California (Miocene–Pleistocene) as well as to periods of glaciation (Pleistocene).

Cruz, J. A., J. A. Velasco, J. Arroyo-Cabrales, and E. Johnson. 2023. Paleoclimatic Reconstruction Based on the Late Pleistocene San Josecito Cave Stratum 720 Fauna Using Fossil Mammals, Reptiles, and Birds. Diversity 15: 881. https://doi.org/10.3390/d15070881

Advances in technology have equipped paleobiologists with new analytical tools to assess the fossil record. The functional traits of vertebrates have been used to infer paleoenvironmental conditions. In Quaternary deposits, birds are the second-most-studied group after mammals. They are considered a poor paleoambiental proxy because their high vagility and phenotypic plasticity allow them to respond more effectively to climate change. Investigating multiple groups is important, but it is not often attempted. Biogeographical and climatic niche information concerning small mammals, reptiles, and birds have been used to infer the paleoclimatic conditions present during the Late Pleistocene at San Josecito Cave (~28,000 14C years BP), Mexico. Warmer and dryer conditions are inferred with respect to the present. The use of all of the groups of small vertebrates is recommended because they represent an assemblage of species that have gone through a series of environmental filters in the past. Individually, different vertebrate groups provide different paleoclimatic information. Birds are a good proxy for inferring paleoprecipitation but not paleotemperature. Together, reptiles and small mammals are a good proxy for inferring paleoprecipitation and paleotemperature, but reptiles alone are a bad proxy, and mammals alone are a good proxy for inferring paleotemperature and precipitation. The current paleoclimatic results coupled with those of a previous vegetation structure analysis indicate the presence of non-analog paleoenvironmental conditions during the Late Pleistocene in the San Josecito Cave area. This situation would explain the presence of a disharmonious fauna and the extinction of several taxa when these conditions later disappeared and do not reappear again.

García-Navarrete, P. G., T. Escalante, D. Espinosa, and J. J. Morrone. 2023. Evolutionary biogeography of the Revillagigedo Archipelago, Mexico. Journal of Natural History 57: 685–709. https://doi.org/10.1080/00222933.2023.2203337

The biotic assembly of the Revillagigedo Archipelago, Mexico, was analysed under an evolutionary biogeographic framework. We undertook a parsimony analysis of endemicity with progressive character elimination of 194 plant and animal species, which allowed us to identify the archipelago as a complex area or node where Nearctic and Neotropical biotic components overlap. We undertook a cladistic biogeographic analysis using the phylogenetic information of 42 taxon-area cladograms, from which one general-area cladogram was obtained: (Revillagigedo, (Sonoran, (Baja California, (Veracruzan, Pacific Lowlands)))). These results suggest that the Revillagigedo Archipelago may be classified as a province, although we prefer to keep it as a district of the Pacific Lowlands province. We identified two cenocrons (temporally integrated set of taxa) that can be dated to the Pliocene–Pleistocene: one Nearctic that dispersed from the Baja California Peninsula, and another Neotropical where the species dispersed from the Pacific coast to the islands. The geological information and the general-area cladograms allowed us to propose a geobiotic scenario for the archipelago where the islands are probably the result of volcanism associated with the oceanic Mathematician Ridge, and the arrival of the cenocrons to the archipelago may have occurred during the Pliocene–Pleistocene, after the islands were available for colonisation.

Cousins-Westerberg, R., N. Dakin, L. Schat, G. Kadereit, and A. M. Humphreys. 2023. Evolution of cold tolerance in the highly stress-tolerant samphires and relatives (Salicornieae: Amaranthaceae). Botanical Journal of the Linnean Society. https://doi.org/10.1093/botlinnean/boad009

Low temperature constitutes one of the main barriers to plant distributions, confining many clades to their ancestrally tropical biome. However, recent evidence suggests that transitions from tropical to temperate biomes may be more frequent than previously thought. Here, we study the evolution of cold and frost tolerance in the globally distributed and highly stress-tolerant Salicornieae (Salicornioideae, Amaranthaceae s.l.). We first generate a phylogenetic tree comprising almost all known species (85-90%), using newly generated (n = 106) and published nuclear-ribosomal and plastid sequences. Next, we use geographical occurrence data to document in which clades and geographical regions cold-tolerant species occur and reconstruct how cold tolerance evolved. Finally, we test for correlated evolution between frost tolerance and the annual life form. We find that frost tolerance has evolved independently in up to four Northern Hemisphere lineages but that annuals are no more likely to evolve frost tolerance than perennials, indicating the presence of different strategies for adapting to cold environments. Our findings add to mounting evidence for multiple independent out-of-the-tropics transitions among close relatives of flowering plants and raise new questions about the ecological and physiological mechanism(s) of adaptation to low temperatures in Salicornieae.

Huber, B. A., G. Meng, J. Král, I. M. Ávila Herrera, M. A. Izquierdo, and L. S. Carvalho. 2023. High and dry: integrative taxonomy of the Andean spider genus Nerudia (Araneae: Pholcidae). Zoological Journal of the Linnean Society. https://doi.org/10.1093/zoolinnean/zlac100

Abstract Ninetinae are a group of poorly known spiders that do not fit the image of ‘daddy long-legs spiders’ (Pholcidae), the family to which they belong. They are mostly short-legged, tiny and live in arid environments. The previously monotypic Andean genus Nerudia exemplifies our poor knowledge of Ninetinae: only seven adult specimens from two localities in Chile and Argentina have been reported in the literature. We found representatives of Nerudia at 24 of 52 localities visited in 2019, mostly under rocks in arid habitats, up to 4450 m a.s.l., the highest known record for Pholcidae. With now more than 400 adult specimens, we revise the genus, describing ten new species based on morphology (including SEM) and COI barcodes. We present the first karyotype data for Nerudia and for its putative sister-genus Gertschiola. These two southern South American genera share a X1X2X3Y sex chromosome system. We model the distribution of Nerudia, showing that the genus is expected to occur in the Atacama biogeographic province (no record so far) and that its environmental niche is phylogenetically conserved. This is the first comprehensive revision of any Ninetinae genus. It suggests that focused collecting may uncover a considerable diversity of these enigmatic spiders.