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Brunner, A., J. R. G. Márquez, and S. Domisch. 2024. Downscaling future land cover scenarios for freshwater fish distribution models under climate change. Limnologica 104: 126139. https://doi.org/10.1016/j.limno.2023.126139

The decreasing freshwater biodiversity trend can be attributed to anthropogenic impacts in terms of climate and land cover change. For targeted conservation efforts, mapping and understanding the distribution of freshwater organisms consists of an important knowledge gap. Spatial modelling approaches offer valuable insights into present-day biodiversity patterns and potential future trajectories, however methodological constraints still hamper the applicability of addressing future climate and land cover change concurrently in one modelling workflow. Compared to climate-only projections, spatially explicit and high-resolution land cover projections have seen less attention, and the lack of such data challenges modelling efforts to predict the possible future effects of land cover change especially on freshwater organisms. Here we demonstrate a workflow where we downscale future land cover projection data from the Shared Socioeconomic Pathway (SSP) scenarios for South America at 1 km2 spatial resolution, to then predict the future habitat suitability patterns of the Colombian fish fauna. Specifically, we show how the land cover data can be converted from plain numbers into a spatially explicit representation for multiple SSP scenarios and at high spatial resolution, employing freshwater-specific downscaling aspects when spatially allocating the land cover category grid cells, and how it can be fitted into an ensemble species distribution modelling approach of 1209 fish species. Our toolbox consists of a suite of open-source tools, including Dinamica EGO, R, GRASS GIS and GDAL, and we provide the code and necessary steps to reproduce the workflow for other study areas. We highlight the feasibility of the downscaling, but also underline the potential challenges regarding the spatial scale and the size of the spatial units of analysis.

Quitete Portela, R. de C., L. Tourinho, T. Viana dos Santos, and M. M. Vale. 2023. Juçara palm ecological interactions threatened by climate and land‐cover changes. Biotropica. https://doi.org/10.1111/btp.13257

Ongoing climate change has caused well‐documented displacements of species' geographic distribution to newly climatically suitable areas. Ecological niche models (ENM) are widely used to project such climate‐induced changes but typically ignore species' interspecific interactions that might facilitate or prevent its establishment in new areas. Here, we projected the change in the distribution of Juçara Palm (Euterpe edulis Mart., Arecaceae), a neotropical threatened palm, taking into consideration its ecological interactions. We run ENMs of E. edulis, plus its known seed dispersers (15 bird species) and predators (19 birds and mammals) under current and future climatic conditions. Additionally, for E. edulis, we removed deforested areas from the model. When considering only climate, climate change has a positive impact on E. edulis, with a predicted westward expansion and a modest southward contraction, with a 26% net gain in distribution by 2060. When removing deforested areas, however, climate change harms E. edulis, with a 66% predicted net distribution loss. Within the palm's distribution in this more realistic model, there is also a predicted reduction in the richness of its dispersers and predators. We conclude that the possible benefits of climate change to E. edulis' distribution are overshadowed by widespread habitat loss, and that global change is likely to disrupt some of its ecological interactions. The outcome of the interplay between the negative impact of the loss of dispersers, and the benefit of the loss of predators, is unclear, but the large contraction of E. edulis' range predicted here foresees a dim future for the species.

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. https://doi.org/10.1007/s13364-023-00707-0

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. 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.

Hill, A., M. F. T. Jiménez, N. Chazot, C. Cássia‐Silva, S. Faurby, L. Herrera‐Alsina, and C. D. Bacon. 2023. Apparent effect of range size and fruit colour on palm diversification may be spurious. Journal of Biogeography. https://doi.org/10.1111/jbi.14683

Aim Fruit selection by animal dispersers with different mobility directly impacts plant geographical range size, which, in turn, may impact plant diversification. Here, we examine the interaction between fruit colour, range size and diversification rate in palms by testing two hypotheses: (1) species with fruit colours attractive to birds have larger range sizes due to high dispersal ability and (2) disperser mobility affects whether small or large range size has higher diversification, and intermediate range size is expected to lead to the highest diversification rate regardless of disperser. Location Global. Time Period Contemporary (or present). Major Taxa Studied Palms (Arecaceae). Methods Palm species were grouped based on likely animal disperser group for given fruit colours. Range sizes were estimated by constructing alpha convex hull polygons from distribution data. We examined disperser group, range size or an interaction of both as possible drivers of change in diversification rate over time in a likelihood dynamic model (Several Examined State-dependent Speciation and Extinction [SecSSE]). Models were fitted, rate estimates were retrieved and likelihoods were compared to those of appropriate null models. Results Species with fruit colours associated with mammal dispersal had larger ranges than those with colours associated with bird dispersal. The best fitting SecSSE models indicated that the examined traits were not the primary driver of the heterogeneity in diversification rates in the model. Extinction rate complexity had a marked impact on model performance and on diversification rates. Main Conclusions Two traits related to dispersal mobility, range size and fruit colour, were not identified as the main drivers of diversification in palms. Increased model extinction rate complexity led to better performing models, which indicates that net diversification should be estimated rather than speciation alone. However, increased complexity may lead to incorrect SecSSE model conclusions without careful consideration. Finally, we find palms with more mobile dispersers do not have larger range sizes, meaning other factors are more important determinants of range size.

Liu, S., S. Xia, D. Wu, J. E. Behm, Y. Meng, H. Yuan, P. Wen, et al. 2022. Understanding global and regional patterns of termite diversity and regional functional traits. iScience: 105538. https://doi.org/10.1016/j.isci.2022.105538

Our understanding of broad-scale biodiversity and functional trait patterns is largely based on plants, and relatively little information is available on soil arthropods. Here, we investigated the distribution of termite diversity globally and morphological traits and diversity across China. Our analyses showed increasing termite species richness with decreasing latitude at both the globally, and within-China. Additionally, we detected obvious latitudinal trends in the mean community value of termite morphological traits on average, with body size and leg length decreasing with increasing latitude. Furthermore, temperature, NDVI and water variables were the most important drivers controlling the variation in termite richness, and temperature and soil properties were key drivers of the geographic distribution of termite morphological traits. Our global termite richness map is one of the first high resolution maps for any arthropod group and especially given the functional importance of termites, our work provides a useful baseline for further ecological analysis.

Moreno, I., J. M. W. Gippet, L. Fumagalli, and P. J. Stephenson. 2022. Factors affecting the availability of data on East African wildlife: the monitoring needs of conservationists are not being met. Biodiversity and Conservation. https://doi.org/10.1007/s10531-022-02497-4

Understanding the status and abundance of species is essential for effective conservation decision-making. However, the availability of species data varies across space, taxonomic groups and data types. A case study was therefore conducted in a high biodiversity region—East Africa—to evaluate data biases, the factors influencing data availability, and the consequences for conservation. In each of the eleven target countries, priority animal species were identified as threatened species that are protected by national governments, international conventions or conservation NGOs. We assessed data gaps and biases in the IUCN Red List of Threatened Species, the Global Biodiversity Information Facility and the Living Planet Index. A survey of practitioners and decision makers was conducted to confirm and assess consequences of these biases on biodiversity conservation efforts. Our results showed data on species occurrence and population trends were available for a significantly higher proportion of vertebrates than invertebrates. We observed a geographical bias, with higher tourism income countries having more priority species and more species with data than lower tourism income countries. Conservationists surveyed felt that, of the 40 types of data investigated, those data that are most important to conservation projects are the most difficult to access. The main challenges to data accessibility are excessive expense, technological challenges, and a lack of resources to process and analyse data. With this information, practitioners and decision makers can prioritise how and where to fill gaps to improve data availability and use, and ensure biodiversity monitoring is improved and conservation impacts enhanced.

Cumer, T., A. P. Machado, F. Siverio, S. I. Cherkaoui, I. Roque, R. Lourenço, M. Charter, et al. 2022. Genomic basis of insularity and ecological divergence in barn owls (Tyto alba) of the Canary Islands. Heredity. https://doi.org/10.1038/s41437-022-00562-w

Islands, and the particular organisms that populate them, have long fascinated biologists. Due to their isolation, islands offer unique opportunities to study the effect of neutral and adaptive mechanisms in determining genomic and phenotypical divergence. In the Canary Islands, an archipelago rich in endemics, the barn owl ( Tyto alba ), present in all the islands, is thought to have diverged into a subspecies ( T. a. gracilirostris ) on the eastern ones, Fuerteventura and Lanzarote. Taking advantage of 40 whole-genomes and modern population genomics tools, we provide the first look at the origin and genetic makeup of barn owls of this archipelago. We show that the Canaries hold diverse, long-standing and monophyletic populations with a neat distinction of gene pools from the different islands. Using a new method, less sensitive to structure than classical F ST , to detect regions involved in local adaptation to insular environments, we identified a haplotype-like region likely under selection in all Canaries individuals and genes in this region suggest morphological adaptations to insularity. In the eastern islands, where the subspecies is present, genomic traces of selection pinpoint signs of adapted body proportions and blood pressure, consistent with the smaller size of this population living in a hot arid climate. In turn, genomic regions under selection in the western barn owls from Tenerife showed an enrichment in genes linked to hypoxia, a potential response to inhabiting a small island with a marked altitudinal gradient. Our results illustrate the interplay of neutral and adaptive forces in shaping divergence and early onset speciation.

Sánchez-González, L. A., H. Cayetano, D. A. Prieto-Torres, O. R. Rojas-Soto, and A. G. Navarro-Sigüenza. 2022. The role of ecological and geographical drivers of lineage diversification in the Squirrel cuckoo Piaya cayana in Mexico: a mitochondrial DNA perspective. Journal of Ornithology. https://doi.org/10.1007/s10336-022-02008-w

The Squirrel Cuckoo ( Piaya cayana ) is a widely distributed neotropical species with 14 recognized subspecies. Two parapatric subspecies are distributed in Mexico. P. c. mexicana is endemic to the seasonally dry tropical forests of western Mexico, and P. c. thermophila is found in humid forests from eastern Mexico to western Colombia. The 2 taxa have a small area of overlap on the Isthmus of Tehuantepec, but there is pronounced phenotypic differentiation, and very few reported intermediate individuals between these forms, leading to debate about the taxonomic status of the Mesoamerican taxa. Based on two mitochondrial genes, we used phylogenetic, phylogeographic, morphological, and ecological modelling analyses to describe the evolutionary relationships and paleo-distributional patterns of P. cayana in Mexico. Divergence time estimates suggest that the split between P. c. mexicana and P. c. thermophila occurred during the Pleistocene, about 1.24 Mya. Morphometrics of Mexican subspecies indicate that tail length and the white tail tips are significantly longer in P. c. mexicana , while P. c. thermophila has a longer and wider bill. Ecological niche analyses indicated that niche similarity between both lineages was lower than expected by chance, while low values on cross-prediction tests suggested that the two lineages have inhabited different environmental spaces since at least the Late Pleistocene. The ecological niche difference may also be associated with a steep humidity gradient, suggesting a significant contemporary environmental barrier. Overall, our results indicate that P. c. mexicana and P. c. thermophila have divergent evolutionary histories; therefore, the current taxonomic status of the Piaya populations in Mexico reflects neither their evolutionary relationships nor their apparent divergence. Our results suggest a major split in the polytypic P. cayana coinciding with the Andes, suggesting that the western endemic P. c. mexicana and P. c. thermophila are best treated as separate species-level taxa . Die Rolle ökologischer und geografischer Faktoren bei der Abstammung und Diversifikation des Eichhornkuckucks Piaya cayana in Mexiko: von der mitochondrialen DNA her betrachtet Der Eichhornkuckuck ( Piaya cayana ) ist eine weit verbreitete neotropische Art mit 14 anerkannten Unterarten. In Mexiko gibt es zwei parapatrische Unterarten. P. c. mexicana ist in den je nach Jahreszeit trockenen tropischen Wäldern Westmexikos beheimatet, während P. c. thermophila in den feuchten Wäldern von Ostmexiko bis Westkolumbien vorkommt. Die beiden Taxa überschneiden sich in einem kleinen Gebiet an der Landenge von Tehuantepec, aber es gibt einen ausgeprägten phänotypischen Unterschied und nur sehr wenige bekannte Mischtypen zwischen den beiden und damit Anlass zu Diskussionen über den taxonomischen Status dieser mittelamerikanischen Taxa. Auf der Grundlage zweier mitochondrialer Gene haben wir phylogenetische, phylogeografische, morphologische und ökologische Modell-Analysen durchgeführt, um die abstammungsbiologischen Verbindungen und Verbreitungsmuster von P. cayana im Paläozän in Mexiko zu bestimmen. Schätzungen der Entstehungszeit der Unterschiede deuten darauf hin, dass die Trennung zwischen P. c. mexicana und P. c. thermophila während des Pleistozäns stattfand, vor etwa 1,24 Millionen Jahren. Die morphometrischen Daten der mexikanischen Unterarten zeigen, dass die Schwanzlänge und die weißen Schwanzspitzen bei P. c. mexicana deutlich länger sind, während P. c. thermophila einen längeren und breiteren Schnabel hat. Analysen der ökologischen Nischen zeigten, dass die Übereinstimmungen zwischen den beiden Linien geringer waren als durch Zufall zu erwarten wäre, während niedrige Werte bei Kreuz-Vorhersagetests darauf hindeuteten, dass die beiden Linien mindestens seit dem späten Pleistozän in unterschiedlichen Lebensräumen gelebt haben müssen. Der ökologische Nischenunterschied kann auch mit dem starken Feuchtigkeitsgradienten zusammenhängen, was auf eine bedeutende gegenwärtige Umweltbarriere hinweist. Insgesamt deuten unsere Ergebnisse darauf hin, dass P. c. mexicana und P. c. thermophila eine unterschiedliche Entwicklungsgeschichte haben; daher gibt der derzeitige taxonomische Status der Piaya-Populationen in Mexiko weder ihre evolutionäre Verwandtschaft, noch ihre offensichtlichen Unterschiede wieder. Unsere Ergebnisse deuten darauf hin, dass sich der polytypische P. cayana in den Anden aufgespalten hat, was bedeuten könnte, dass die im Westen endemischen P. c. mexicana und P. c. thermophila am besten als separate Taxa auf Artniveau behandelt werden sollten.

Dantas, V. L., and J. G. Pausas. 2022. The legacy of the extinct Neotropical megafauna on plants and biomes. Nature Communications 13. https://doi.org/10.1038/s41467-021-27749-9

Large mammal herbivores are important drivers of plant evolution and vegetation patterns, but the extent to which plant trait and ecosystem geography currently reflect the historical distribution of extinct megafauna is unknown. We address this question for South and Central America (Neotropical bio…