Science Enabled by Specimen Data

Cheeseman, A. E., D. S. Jachowski, and R. Kays. 2024. From past habitats to present threats: tracing North American weasel distributions through a century of climate and land use change. Landscape Ecology 39.

Context Shifts in climate and land use have dramatically reshaped ecosystems, impacting the distribution and status of wildlife populations. For many species, data gaps limit inference regarding population trends and links to environmental change. This deficiency hinders our ability to enact meaningful conservation measures to protect at risk species. Objectives We investigated historical drivers of environmental niche change for three North American weasel species (American ermine, least weasel, and long-tailed weasel) to understand their response to environmental change. Methods Using species occurrence records and corresponding environmental data, we developed species-specific environmental niche models for the contiguous United States (1938–2021). We generated annual hindcasted predictions of the species’ environmental niche, assessing changes in distribution, area, and fragmentation in response to environmental change. Results We identified a 54% decline in suitable habitat alongside high levels of fragmentation for least weasels and region-specific trends for American ermine and long-tailed weasels; declines in the West and increased suitability in the East. Climate and land use were important predictors of the environmental niche for all species. Changes in habitat amount and distribution reflected widespread land use changes over the past century while declines in southern and low-elevation areas are consistent with impacts from climatic change. Conclusions Our models uncovered land use and climatic change as potential historic drivers of population change for North American weasels and provide a basis for management recommendations and targeted survey efforts. We identified potentially at-risk populations and a need for landscape-level planning to support weasel populations amid ongoing environmental changes.

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.

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.

Gama-Rodríguez, A. M., J. A. García, L. F. Lozano, and D. A. Prieto-Torres. 2024. Protecting breeding sites: a critical goal for the conservation of the golden eagle in Mexico under global change scenarios. Journal of Ornithology.

Impacts of global climate and land‐use changes on distribution patterns and breeding sites remain today poorly studied for several vulnerable emblematic bird species, including the Golden Eagle ( Aquila chrysaetos ). Herein, we analyzed the potential effect of global climate changes and agricultural activities on the distribution patterns of this top predator across Mexico. We assessed the long-term role of protected areas (PAs) for safeguarding the species’ overall distribution and its breeding sites. We evaluated current and future (2040s, 2060s, and 2080s) threats from global change using ecological niche modeling and geographic information system approaches to determine the percentage of the species’ distribution area that overlaps with highly human-modified areas and PAs under each climate scenario. We also used niche overlap tests to assess whether the species’ breeding sites show equivalence or similarity of climatic conditions over time. Our findings revealed shifts in the Golden Eagle’s distributional area, with an overall size reduction (by ~ 57% in the 2040s and ~ 78% in the 2080s) due to future environmental changes, mainly attributable to increasingly dry and warm conditions. Mexican PAs cover ~ 12% of the Golden Eagle’s range across country, but this decreased by > 33% on average under the species’ future distributions. Although the hypothesis of equivalent climatic conditions at breeding sites over time was rejected, those sites did have long-term climate similarity (niche overlap: 0.75–0.83; P  < 0.05). Considering the species’ nest site fidelity and that colonization of new areas within Mexico seems unlikely, protection of these breeding sites is a critical step for the long-term conservation of this emblematic species in Mexico. Brutplätze schützen: ein wichtiges Ziel für die Erhaltung des Steinadlers in Mexiko unter den Bedingungen des globalen Wandels Die Auswirkungen globaler Klima- und Landnutzungsänderungen auf die Verbreitungsmuster und Brutplätze mehrerer gefährdeter, symbolträchtiger Vogelarten, darunter der Steinadler (Aquila chrysaetos), sind bis heute kaum untersucht. In dieser Studie haben wir die potenziellen Auswirkungen globaler Klimaveränderungen und landwirtschaftlicher Aktivitäten auf die Verbreitungsmuster dieses Spitzenprädators in Mexiko untersucht. Wir bewerteten die langfristige Rolle von Schutzgebieten für die Sicherung der Gesamtverbreitung der Art und ihrer Brutplätze. Wir bewerteten aktuelle und zukünftige (2040, 2060 und 2080) Bedrohungen durch den globalen Wandel, indem wir ökologische Nischenmodelle und geografische Informationssysteme einsetzten, um den prozentualen Anteil des Verbreitungsgebiets der Art zu bestimmen, der sich mit stark vom Menschen veränderten Gebieten und Schutzgebieten unter jedem Klimaszenario überschneidet. Außerdem haben wir mit Hilfe von Nischenüberlappungstests untersucht, ob die Brutgebiete der Art im Laufe der Zeit gleichwertige oder ähnliche klimatische Bedingungen aufweisen. Unsere Ergebnisse zeigen, dass sich das Verbreitungsgebiet des Steinadlers aufgrund zukünftiger Umweltveränderungen insgesamt verkleinert (um ca. 57% in den 2040er Jahren und ca. 78% in den 2080er Jahren), was hauptsächlich auf zunehmend trockenere und wärmere Bedingungen zurückzuführen ist. Die mexikanischen Schutzgebiete decken landesweit etwa 12% des Verbreitungsgebiets des Steinadlers ab, doch wird dieser Anteil unter den zukünftigen Verbreitungsgebieten der Art im Durchschnitt um mehr als 33% abnehmen. Auch wenn wir die Hypothese über die Zeit gleichwertiger klimatischer Bedingungen an den Brutplätzen Zeit verwarfen, wiesen diese Standorte eine langfristige Klimaähnlichkeit auf (Nischenüberschneidung: 0,75-0,83; P < 0,05). In Anbetracht der Nistplatztreue der Art und der Tatsache, dass die Besiedlung neuer Gebiete in Mexiko unwahrscheinlich erscheint, ist der Schutz dieser Brutplätze ein entscheidender Schritt für die langfristige Erhaltung dieser emblematischen Art in Mexiko.

Chavez-Lugo, E. G., E. J. Cruz-Bazan, A. Cruz-Anaya, J. A. Encina-Domínguez, and J. E. Ramírez-Albores. 2024. From the mountains to the valley: the Golden Eagle (Aquila chrysaetos) in Coahuila, Mexico. Huitzil Revista Mexicana de Ornitologí­a 24: e661.

El Águila Real (Aquila chrysaetos) es una rapaz amenazada a nivel nacional, que se distribuye desde el norte del país hasta el centro de México. Sin embargo, existen escasos reportes de su presencia dentro del rango de distribución en México, como es el caso para Coahuila. Hicimos observaciones en campo en la región sureste de Coahuila durante el periodo de 2017 al 2023, complementada con una revisión de los registros de monitoreo en campo en diferentes bases de datos. Con estos registros, generamos una modelación de idoneidad ambiental para Aquila chrysaetos utilizando el algoritmo MaxEnt para identificar zonas prioritarias para la conservación que no se encuentran dentro de un área natural protegida. Los registros encontrados de individuos de A. chrysaetos evidenciaron en gran medida que la mayor probabilidad de ocurrencia se encuentra en la parte noroeste y sureste de Coahuila en zonas de matorral desértico y pastizal natural. El modelo de idoneidad climática indicó que las zonas prioritarias para conservación se ubicaron adyacentes a las áreas naturales como Maderas del Carmen, Sierra de Arteaga, Sierra de Zapalinamé, Ocampo y Don Martín. Nuestra modelación de la idoneidad climática para A. chrysaetos nos permitió identificar zonas prioritarias para la conservación que no se encuentran dentro de un área natural protegida, lo que implica que estas zonas idóneas para que habite A. chrysaetos sean consideradas prioritarias para la conservación de la especie.

Leão, C. F., M. S. Lima Ribeiro, K. Moraes, G. S. R. Gonçalves, and M. G. M. Lima. 2023. Climate change and carnivores: shifts in the distribution and effectiveness of protected areas in the Amazon. PeerJ 11: e15887.

Background Carnivore mammals are animals vulnerable to human interference, such as climate change and deforestation. Their distribution and persistence are affected by such impacts, mainly in tropical regions such as the Amazon. Due to the importance of carnivores in the maintenance and functioning of the ecosystem, they are extremely important animals for conservation. We evaluated the impact of climate change on the geographic distribution of carnivores in the Amazon using Species Distribution Models (SDMs). Do we seek to answer the following questions: (1) What is the effect of climate change on the distribution of carnivores in the Amazon? (2) Will carnivore species lose or gain representation within the Protected Areas (PAs) of the Amazon in the future? Methods We evaluated the distribution area of 16 species of carnivores mammals in the Amazon, based on two future climate scenarios (RCP 4.5 and RCP 8.5) for the year 2070. For the construction of the SDMs we used bioclimatic and vegetation cover variables (land type). Based on these models, we calculated the area loss and climate suitability of the species, as well as the effectiveness of the protected areas inserted in the Amazon. We estimated the effectiveness of PAs on the individual persistence of carnivores in the future, for this, we used the SDMs to perform the gap analysis. Finally, we analyze the effectiveness of PAs in protecting taxonomic richness in future scenarios. Results The SDMs showed satisfactory predictive performance, with Jaccard values above 0.85 and AUC above 0.91 for all species. In the present and for the future climate scenarios, we observe a reduction of potencial distribution in both future scenarios (RCP4.5 and RCP8.5), where five species will be negatively affected by climate change in the RCP 4.5 future scenario and eight in the RCP 8.5 scenario. The remaining species stay stable in terms of total area. All species in the study showed a loss of climatic suitability. Some species lost almost all climatic suitability in the RCP 8.5 scenario. According to the GAP analysis, all species are protected within the PAs both in the current scenario and in both future climate scenarios. From the null models, we found that in all climate scenarios, the PAs are not efficient in protecting species richness.

Rosas, M. R., R. A. Segovia, and P. C. Guerrero. 2023. Climatic Niche Dynamics of the Astereae Lineage and Haplopappus Species Distribution following Amphitropical Long-Distance Dispersal. Plants 12: 2721.

The tribe Astereae (Asteraceae) displays an American Amphitropical Disjunction. To understand the eco-evolutionary dynamics associated with a long-distance dispersal event and subsequent colonization of extratropical South America, we compared the climatic and geographic distributions of South American species with their closest North American relatives, focusing on the diverse South American Astereae genus, Haplopappus. Phylogenetic analysis revealed that two South American genera are closely related to seven North American genera. The climatic niche overlap (D = 0.5) between South and North America exhibits high stability (0.89), low expansion (0.12), and very low unfilling (0.04). The distribution of the North American species predicted the climatic and geographic space occupied by the South American species. In central Chile, Haplopappus showed a non-random latitudinal gradient in species richness, with Mediterranean climate variables mainly explaining the variation. Altitudinal patterns indicated peak richness at 600 m, declining at lower and higher elevations. These findings support climatic niche conservatism in shaping Haplopappus species distribution and diversity. Two major endemism zones were identified in central Chile and the southern region, with a transitional zone between Mediterranean and Temperate macro-bioclimates. Our results indicate strong niche conservatism following long-distance dispersal and slight niche expansion due to unique climatic variables in each hemisphere.

Vázquez-Rueda, E., A. P. Cuervo-Robayo, and J. Ayala-Berdon. 2023. Forest dependency could be more important than dispersal capacity for habitat connectivity of four species of insectivorous bats inhabiting a highly anthropized region in central Mexico. Mammal Research.

The maintenance, restoration, and improvement of habitat structure are critical for biodiversity conservation. Under this context, studies assessing habitat connectivity become essential, especially those focused on anthropized regions holding high species richness. We calculated the habitat connectivity of four species of insectivorous bats with different dispersal capacity and habitat preferences in a highly anthropized region in central Mexico, Idionycteris phyllotis and Myotis thysanodes , with a high dispersal capacity and forest-dependency, and Eptesicus fuscus with a low dispersal capacity, and Tadarida brasiliensis with a high dispersal capacity, as the more tolerant bat species to anthropogenic disturbance. We developed niche-based species distribution models to identify suitable habitat patches for each species. We then assessed habitat connectivity and the importance of suitable habitat patches for maintaining connectivity using a graph theory approach. Our results showed that forest dependency was most important than dispersal capacity for connectivity. We also found that the Iztaccíhuatl-Popocatépetl mountain, a National Park comprising 4.2% of natural vegetation in the study area, was the most critical patch for maintaining connectivity for most of the study species. Our study demonstrates the importance of conserving the remnants of natural vegetation for maintaining habitat connectivity within a fragmented landscape and demonstrates the importance of conserving protected areas as well as other remnants of vegetation for the maintenance of habitat connectivity within a fragmented landscape.

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.

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.

Quillfeldt, P., Y. Bedolla-Guzmán, M. M. Libertelli, Y. Cherel, M. Massaro, and P. Bustamante. 2023. Mercury in Ten Storm-Petrel Populations from the Antarctic to the Subtropics. Archives of Environmental Contamination and Toxicology.

The oceans become increasingly contaminated as a result of global industrial production and consumer behaviour, and this affects wildlife in areas far removed from sources of pollution. Migratory seabirds such as storm-petrels may forage in areas with different contaminant levels throughout the annual cycle and may show a carry-over of mercury from the winter quarters to the breeding sites. In this study, we compared mercury levels among seven species of storm-petrels breeding on the Antarctic South Shetlands and subantarctic Kerguelen Islands, in temperate waters of the Chatham Islands, New Zealand, and in temperate waters of the Pacific off Mexico. We tested for differences in the level of contamination associated with breeding and inter-breeding distribution and trophic position. We collected inert body feathers and metabolically active blood samples in ten colonies, reflecting long-term (feathers) and short-term (blood) exposures during different periods ranging from early non-breeding (moult) to late breeding. Feathers represent mercury accumulated over the annual cycle between two successive moults. Mercury concentrations in feathers ranged over more than an order of magnitude among species, being lowest in subantarctic Grey-backed Storm-petrels (0.5 μg g −1 dw) and highest in subtropical Leach’s Storm-petrels (7.6 μg g −1 dw, i.e. posing a moderate toxicological risk). Among Antarctic Storm-petrels, Black-bellied Storm-petrels had threefold higher values than Wilson’s Storm-petrels, and in both species, birds from the South Shetlands (Antarctica) had threefold higher values than birds from Kerguelen (subantarctic Indian Ocean). Blood represents mercury taken up over several weeks, and showed similar trends, being lowest in Grey-backed Storm-petrels from Kerguelen (0.5 μg g −1 dw) and highest in Leach’s Storm-petrels (3.6 μg g −1 dw). Among Antarctic storm-petrels, species differences in the blood samples were similar to those in feathers, but site differences were less consistent. Over the breeding season, mercury decreased in blood samples of Antarctic Wilson’s Storm-petrels, but did not change in Wilson’s Storm-petrels from Kerguelen or in Antarctic Black-bellied Storm-petrels. In summary, we found that mercury concentrations in storm-petrels varied due to the distribution of species and differences in prey choice. Depending on prey choices, Antarctic storm-petrels can have similar mercury concentrations as temperate species. The lowest contamination was observed in subantarctic species and populations. The study shows how seabirds, which accumulate dietary pollutants in their tissues in the breeding and non-breeding seasons, can be used to survey marine pollution. Storm-petrels with their wide distributions and relatively low trophic levels may be especially useful, but more detailed knowledge on their prey choice and distributions is needed.

Huang, T., J. Chen, K. E. Hummer, L. A. Alice, W. Wang, Y. He, S. Yu, et al. 2023. Phylogeny of Rubus (Rosaceae): Integrating molecular and morphological evidence into an infrageneric revision. TAXON.

Rubus (Rosaceae), one of the most complicated angiosperm genera, contains about 863 species, and is notorious for its taxonomic difficulty. The most recent (1910–1914) global taxonomic treatment of the genus was conducted by Focke, who defined 12 subgenera. Phylogenetic results over the past 25 years suggest that Focke's subdivisions of Rubus are not monophyletic, and large‐scale taxonomic revisions are necessary. Our objective was to provide a comprehensive phylogenetic analysis of the genus based on an integrative evidence approach. Morphological characters, obtained from our own investigation of living plants and examination of herbarium specimens are combined with chloroplast genomic data. Our dataset comprised 196 accessions representing 145 Rubus species (including cultivars and hybrids) and all of Focke's subgenera, including 60 endemic Chinese species. Maximum likelihood analyses inferred phylogenetic relationships. Our analyses concur with previous molecular studies, but with modifications. Our data strongly support the reclassification of several subgenera within Rubus. Our molecular analyses agree with others that only R. subg. Anoplobatus forms a monophyletic group. Other subgenera are para‐ or polyphyletic. We suggest a revised subgeneric framework to accommodate monophyletic groups. Character evolution is reconstructed, and diagnostic morphological characters for different clades are identified and discussed. Based on morphological and molecular evidence, we propose a new classification system with 10 subgenera: R. subg. Anoplobatus, R. subg. Batothamnus, R. subg. Chamaerubus, R. subg. Cylactis, R. subg. Dalibarda, R. subg. Idaeobatus, R. subg. Lineati, R. subg. Malachobatus, R. subg. Melanobatus, and R. subg. Rubus. The revised infrageneric nomenclature inferred from our analyses is provided along with synonymy and type citations. Our new taxonomic backbone is the first systematic and complete global revision of Rubus since Focke's treatment. It offers new insights into deep phylogenetic relationships of Rubus and has important theoretical and practical significance for the development and utilization of these important agronomic crops.