The species is an endemic reptile occupying isolated high-elevation habitats in the Coastal and Andean mountain ranges of central Chile, from southern Coquimbo to northern O’Higgins. It generally occurs between 2,000 and 2,800 metres above sea level. Such sky-island populations are separated from one another by warmer, drier valleys and have progressively less connected habitat as temperature and precipitation patterns change. The International Union for Conservation of Nature lists L. nigroviridis as Least Concern, although earlier work has identified potential risks from climate change and anthropization. The new analysis examined how the species’ climate envelope might change and where human occupation could constrain movement between mountain areas.

For the analysis, researchers used 199 georeferenced presence records from 53 localities, compiled from literature, museum catalogues, GBIF and iNaturalist and filtered for geographic precision. They generated 597 pseudoabsences with the BIOMOD2 package. A preliminary sensitivity analysis using the True Skill Statistic indicated that this number maintained accuracy without overfitting. The final modelling used a Random Forest algorithm in five repeated runs, dividing the records into 80% training and 20% testing sets in each run. The best-performing model achieved a True Skill Statistic of 0.86 and a receiver operating characteristic value of 0.98, metrics interpreted in the study as indicating good discrimination between presence and absence.

Six variables from WorldClim 2 were retained: mean diurnal temperature range, temperature seasonality, minimum temperature of the coldest month, annual precipitation, precipitation during the driest quarter and precipitation during the warmest quarter. Their selection combined the species’ thermal ecology, previous modelling work on Liolaemus, tests of multicollinearity through the Variance Inflation Factor, and Random Forest importance scores. Future layers came from the CMIP6 MPI-ESM1-2-HR model under RCP 4.5 and RCP 8.5 for 2040 and 2080. High-suitability areas were defined as those with a predicted presence probability greater than 0.6. The analysis then compared their area and mapped projected gains and losses across the study region.

The range contraction varied markedly among scenarios. The high-probability area was 3,538.2 square kilometres under 2040 RCP 4.5, 3,465.7 under 2040 RCP 8.5, 3,336.3 under 2080 RCP 4.5 and 2,058.0 under 2080 RCP 8.5. Relative to current conditions, the corresponding total changes were −1.1%, −3.1%, −6.7% and −42.5%. In the most severe scenario, 59.1% of the current area was projected to be lost and 16.6% gained. The sharp contrast between the 2080 scenarios indicates that the model outcome depended strongly on the greenhouse-gas pathway used to generate the future climate layers.

Geographically, the 2080 RCP 8.5 projection contained no high-probability climate envelope in Coquimbo, where the species is currently present. A small area around the mountains near Coltauco remained in the Coastal Range, limiting southward expansion in that part of the distribution. In the Andes, however, the southern limit shifted toward Chimbarongo–Las Peñas, north of the Alto Huemul nature sanctuary. The maximum southward displacement was 33.8 kilometres in the 2040 RCP 8.5 projection and 60.6 kilometres in the 2080 RCP 8.5 projection. The model therefore supported the study’s expectation of a southward movement and reduced geographic range, but it did not project the anticipated shift to higher elevations through 2080.

The absence of an altitudinal displacement may reflect both the species’ biology and the limits of the modelled period and scenarios. In the Coastal Range, the available habitat already reaches 2,281 metres, leaving limited space for an uphill move. The Andes contain many peaks above 4,000 metres, but the model did not identify high-probability conditions there under the scenarios examined. The authors suggest that the magnitude of climatic change through 2080 may be insufficient to reveal a significant altitudinal shift for this species. They also note that the timing of such movements varies among taxa and can extend from decades to centuries, with rapid shifts more readily observed in highly mobile organisms.

Land-use information was added after the climate models were produced, using a WorldCover layer that mapped croplands and built environments. It was not a forecast of future urban expansion and therefore represented a conservative account of the barriers the species could encounter. The mapped human footprint was greater in the Coastal Range than in the Andes. This contrast matters for the projected difference between the two mountain systems: Andean populations had a potential route toward newly suitable southern areas without the same concentration of croplands and buildings, while Coastal populations would face a denser network of human land uses if suitable conditions eventually shifted beyond Coltauco. River basins can also impede dispersal among Andean populations, although the study did not identify a comparable concentration of cropland and buildings along that route.

The climate variables used in the model point toward warming and drying in the study area. Under 2080 RCP 8.5, minimum temperature of the coldest month increased by 70.97%, annual precipitation decreased by 28.90%, and precipitation during the driest and warmest quarters remained unchanged. The authors connect these patterns with reduced humidity in central Chile and potential changes in the shrub habitats used by Liolaemus for thermoregulation. Field observations cited in the study describe lizards basking in the morning and retreating into shaded vegetation to avoid overheating and dehydration. The projections do not directly demonstrate changes in plant recruitment, activity time or population survival, but they identify climatic variables that could affect the conditions on which the species depends.

Humidity may also influence the insect prey of this mainly insectivorous lizard. The evidence reviewed by the authors links humidity with insect survival, reproduction, movement and migration, while low humidity can constrain some insect species. For the lizard, these relationships provide a possible route by which climatic drying could affect food resources in addition to direct thermal stress. The study did not measure prey abundance, feeding success or reproduction, however, so these remain ecological mechanisms discussed in relation to the model rather than quantified outcomes. The robust findings are the projected contraction and southward movement of the climate envelope, the regional disappearance of high-probability conditions in Coquimbo, and the differing land-use constraints facing Coastal and Andean populations.

The authors present assisted migration as a possible future option, particularly for Coastal populations that may be unable to cross human barriers while tracking shifting climate conditions. Human-assisted translocation is generally discussed for species with limited dispersal capacity, but it may also be considered when otherwise mobile species cannot reach newly suitable habitat because of anthropogenic barriers. The modelling study did not implement or evaluate a translocation, establish that one would be necessary or safe, or test possible ecological and genetic consequences. Its broader contribution is to show how climate projections and land-use maps can be combined to identify differing vulnerability among populations of the same species. The authors suggest that this approach could also inform research on other central Chilean reptiles with similar habitat requirements, including Liolaemus bellii, Liolaemus leopardinus and Pristidactylus volcanensis, for which additional ecological and physiological work would be needed.

Subject of Research: Modelled climate and land-use vulnerability of the Chilean sky island lizard Liolaemus nigroviridis

Article Title: Assessing the vulnerability of a sky island lizard to climate and land-use change

Article References: Mella-Romero, J., Maya-Miranda, S., Véliz, D., & Simonetti, J. A. (2024). Assessing the vulnerability of a sky island lizard to climate and land-use change. Herpetozoa, 37, 257-267. https://doi.org/10.3897/herpetozoa.37.e125163

Image Credits: AI Generated

DOI: 10.3897/herpetozoa.37.e125163

Keywords: Liolaemus nigroviridis, species distribution modelling, climate change, land-use change, sky islands, central Chile, Andean Range, Coastal Range, Random Forest, conservation, Assessing, vulnerability

Calosoma pentheri is a remarkable creature. It lives above 2,000 meters in mountain pastures with low vegetation, emerging briefly in spring just after snowcaps melt before the habitat becomes too arid. Its wings are significantly reduced, rendering it flightless, which means its populations cannot easily disperse between mountain ranges. This low dispersal capacity, combined with its disjunct geographic distribution across the Western Balkans, makes it an ideal system for studying how past climates shaped genomic structure and population dynamics in rugged mountain landscapes.

The Western Balkans are one of the main centers of endemism in the Palearctic region, shaped by rugged mountains, extensive karst systems, and complex water drainages. During the Miocene, major tectonic and climatic changes in the Eastern and Central Paratethys region drastically reshaped the peninsula, fragmenting populations and triggering geographic and genetic structuring. Unlike northern Palearctic regions covered by large ice sheets, the Western Balkans had smaller, topographically restricted ice caps, allowing regional populations to survive glacial periods rather than face local extinction. This created a dense network of microrefugia that helped maintain genetic diversity over time.

To investigate the evolutionary history of Calosoma pentheri, the research team sampled all major known populations across the Western Balkans, collecting 10 specimens of the northern lineage Calosoma pentheri pentheri and 54 specimens of the southern lineage Calosoma pentheri relictum. Fieldwork took place across Albania and North Macedonia between 2003 and 2022. Historical specimens were borrowed from natural history collections in Geneva, Munich, Basel, and Vienna, demonstrating that museum specimens can provide robust genomic data for phylogeographic analyses.

The team generated a high-quality reference genome from a freshly collected specimen of Calosoma pentheri relictum from Šar Planina in North Macedonia. PacBio HiFi sequencing produced an assembly of 214.8 Mb with 98.6% genome completeness based on the universal single-copy ortholog gene set for Insecta. They then used a hybridization capture approach called hyRAD, which employs RAD probes synthesized from high-quality DNA samples, to generate genomic data from both fresh and historical specimens. After mapping captured reads against an in silico reference catalog built from the reference genome, they recovered 10,794 single nucleotide polymorphisms and 2,278 loci for downstream analyses.

Population genomic analyses revealed clear genetic differentiation between the two lineages. Principal components analysis showed complete separation between Calosoma pentheri pentheri and Calosoma pentheri relictum, while STRUCTURE analyses supported two evolutionarily independent lineages with no signal of recent hybridization between them. Fixation indices indicated strong differentiation between the two lineages (Fst’ = 0.474) and moderate population structure within Calosoma pentheri relictum (Fst’ = 0.176). Within the southern lineage, populations from Bistra, Tetovo, and Ljuboten were distinct from the rest, while Korab and Dešat showed evidence of admixture between clusters.

Phylogenomic analyses recovered both lineages as reciprocally monophyletic with strong branch support across all datasets, whether historical samples were included or not. Divergence time estimation using 300 clock-like loci in BEAST recovered an origin of Calosoma pentheri sensu lato in the Late Miocene, with the two modern lineages splitting approximately 6 million years ago (95% credibility interval: 5.15–7.18 Ma). This indicates that the separation between the two lineages largely predated the onset of Quaternary glaciations around 2.6 million years ago.

The evolutionary scenario proposed by the researchers is shaped by climatic shifts in the Neogene. They hypothesize that the ancestor of both species likely occupied the entire range currently inhabited by both lineages during the Late Miocene, when progressive global cooling around 7 million years ago allowed a wider ancestral distribution across mid-elevation mountain ranges. As global climate warmed progressively between the Late Miocene and the Pliocene Thermal Maximum, these ephemeral refugia became too warm and both lineages dispersed to higher elevations on each side of the ancestral range. These alpine refugia functioned as isolated mountain ranges, or sky islands, with no opportunity for dispersal in flightless species.

During Pleistocene glacial periods, secondary contact between the two species may have occurred in mid-elevation glacial refugia, but this time without gene flow due to complete genetic sorting. The absence of evidence of recent admixture between the two species suggests that gene flow ceased long before the onset of Quaternary glaciations. Within each lineage, however, climatic oscillations during Quaternary ice ages triggered admixture between populations of each massif. In Calosoma pentheri pentheri, one admixture event was inferred between the ancestors of Rosni, Čakor, and Greben localities. In Calosoma pentheri relictum, two admixture events were inferred: one between Ljuboten and Korab, and another between Korab and Dešat.

The researchers conclude that both species should be regarded as bona species, in line with the morphological studies of Jeannel (1940) and Obydov (2002). Since Bruschi (2013) did not formally synonymize the two species, there is no nomenclatural act to be performed, but future work should regard Calosoma pentheri and Calosoma relictum as distinct species. The fine-scale biogeographic processes observed for these beetles likely occur in other endemic lineages of the Western Balkans. Given the pace of global climate change, the same processes of range contraction that drove these evolutionary patterns could now result in the extinction of flora and fauna in sky island archipelagoes. Many of the sampled localities are at or near the altitudinal limits of these mountains, and further range contraction fueled by global warming would lead to the unequivocal extinction of many sky island lineages in the long term.

Subject of Research: Evolutionary biology

Article Title: Climatic swings triggered incipient postglacial speciation of flightless Calosoma beetles in Western Balkan sky islands

Article References: Cardenas, C. R., Gauthier, J., Mottaz, H., Bilat, J., Hristovski, S., & Toussaint, E. F. A. (2026). Climatic swings triggered incipient postglacial speciation of flightless Calosoma beetles in Western Balkan sky islands. Frontiers of Biogeography, 19, Article e181379. https://doi.org/10.21425/fob.19.181379

Image Credits: AI Generated

DOI: 10.21425/fob.19.181379

Keywords: Calosoma, speciation, phylogeography, sky islands, Western Balkans, museomics, climate change, hyRAD, Climatic, swings, triggered, incipient

The research, conducted by Carlos E. Gonzalez-Orozco of the Colombian Agricultural Research Corporation AGROSAVIA, tackles a deceptively simple question: where are the areas of highest biodiversity, and how can biodiversity, biogeography, and agricultural information be combined to prioritize conservation? To answer it, the study focused on six strategic páramo complexes in the Central and Eastern Cordilleras of Colombia: Santurbán-Berlín, Almorzadero, Guantiva-La Rusia, Cruz Verde-Sumapaz, Los Nevados, and Sonsón. Around each páramo, the author drew a five-kilometer buffer zone representing the transition area where farmland meets high-elevation wilderness, and it is precisely in these transition zones that the analysis found the heaviest anthropogenic pressure.

The scale of agricultural encroachment documented in the study is striking. Reported rates of land-use change have reached up to 18.3 percent in the Eastern Cordillera and 8.7 percent in the Central Cordillera. In Santurbán, cultivated land expanded by 10.5 percent between 2000 and 2021, while in Rabanal-Guerrero it increased by 32 percent between 1984 and 2021. These figures capture only the slow, persistent creep of the agricultural frontier; they do not include the compounding effects of intensive grazing, burning, population growth, and climate change, all of which are degrading both the core páramo areas and their surrounding buffers. For an ecosystem that stores water and supports unique evolutionary lineages, such losses are effectively irreversible on human timescales.

What makes the new study methodologically interesting is its integration of multiple, normally separate, strands of spatial analysis. The author compiled 23,938 georeferenced records of native páramo flora representing 2,462 species, of which 8,742 records covering 1,124 species fell within páramo boundaries, plus 1,656 records of 37 Espeletia species restricted to páramo ecosystems. Using the software Biodiverse at a grid resolution of roughly five kilometers, the study mapped species richness, endemism, and a suite of phylogenetic metrics: Phylogenetic Diversity, Phylogenetic Endemism, Relative Phylogenetic Diversity, and Relative Phylogenetic Endemism. A technique called CANAPE, the Categorical Analysis of Neo- and Paleo-Endemism, was then used to distinguish areas where recently evolved species concentrate from those harboring ancient evolutionary relicts, with statistical significance assessed through randomization tests of 999 iterations.

The results reveal a fascinating spatial decoupling that has major implications for conservation strategy. The main centers of species richness do not coincide with the main centers of endemism. Los Nevados, in the Central Cordillera, contains large areas of high species richness but comparatively low endemism, while Santurbán shows the highest concentrations of endemic species without matching levels of richness. For the frailejones themselves, the richest zone lies in southern Guantiva-La Rusia, with outstanding endemism in Guantiva-La Rusia and Santurbán-Berlín, particularly at the lower elevation limits near the buffer zones. The families Orchidaceae, Asteraceae, Melastomataceae, Poaceae, and Solanaceae dominate the flora of both páramos and buffers. In other words, protecting the most species-rich places alone would leave much of Colombia’s unique evolutionary history unprotected.

The phylogenetic analyses add a deeper temporal dimension to this picture. Significantly low Relative Phylogenetic Diversity values, indicating concentrations of short branches and thus recent, rapid diversification, occurred in the buffer zones of Santurbán-Berlín, Sonsón, and Los Nevados, while high values reflecting long evolutionary branches were found in Los Nevados, Santurbán-Berlín-Almorzadero, Guantiva-La Rusia, and Cruz Verde-Sumapaz. The CANAPE analysis identified buffer zones as containing most of the mixed endemism sites, scattered paleoendemism in Cruz Verde-Sumapaz and Santurbán-Berlín, and a distinct center of Espeletia neoendemism in Guantiva-La Rusia. A biogeographic regionalization based on species turnover among 50 Espeletia species across Venezuela, Colombia, and Ecuador identified six distinct regions, with the Eastern Cordillera showing the highest turnover and the páramos splitting into a larger Eastern Cordillera group and a smaller Central Cordillera group. Notably, Los Nevados clustered floristically with the central Eastern Cordillera despite its geographic separation.

Geodiversity, the variety of abiotic features such as soils, geomorphology, hydrology, and climate, emerged as a powerful complementary lens. Nine environmental variables were combined into an integrated geodiversity layer, and statistical comparisons using one-way ANOVA and Tukey post hoc tests showed that maximum geodiversity values differ significantly among all six páramos. Two clear groups emerged: Santurbán-Berlín, Almorzadero, and Guantiva-La Rusia in the Eastern Cordillera showed high to medium geodiversity, while Los Nevados and Sonsón in the Central Cordillera showed medium to low values. Although geodiversity alone does not predict species richness, areas of high geodiversity tended to coincide with elevated species and phylogenetic endemism, reinforcing its value as an indicator of irreplaceable evolutionary heritage.

On the agricultural side, the study used principal component analysis of WorldClim climate variables to delineate agroclimatic zones, finding that solar radiation explained more than 90 percent of the variation, followed by precipitation and relative humidity. Santurbán-Berlín and Los Nevados contain the highest number of agroclimatic zones, six each. Data from Colombia’s Rural Agricultural Planning Unit, UPRA, were then used to track agricultural frontier expansion for 2018, 2021, and 2024, alongside livestock production units from the 2018 National Agricultural Census. The analysis showed that expansion between 2018 and 2024 is most critical in the buffer zones, especially east and south of Guantiva-La Rusia, while within the páramos the frontier has advanced furthest into southern Santurbán-Berlín and northern Cruz Verde-Sumapaz. Crucially, the areas climatically suitable for agriculture often overlap with zones of high biodiversity, creating the spatial conflicts that make páramo conservation so contentious.

Bringing all these layers together, the study produces a clear regional ranking. Santurbán-Berlín emerges as the very highest priority because of its concentration of endemic species and unique evolutionary diversity, especially in its buffer zones. Guantiva-La Rusia follows, exposed to a large and extensive agricultural frontier pressing against its boundaries, and Almorzadero ranks third, facing greater agricultural pressure inside its protected areas. Los Nevados, despite holding the highest species richness, faces comparatively low frontier pressure, while Cruz Verde-Sumapaz presents a paradox: high agricultural risk but mid-range biodiversity values, with relevant phylogenetic endemism concentrated in its northern extreme. At the territorial scale, the study identifies 46 municipalities and 185 rural sites, or veredas, where future conservation interventions could be targeted, with Santurbán-Berlín and Guantiva-La Rusia containing the largest numbers of priority municipalities. Eleven of the prioritized municipalities also fall within PDET and ZOMAC designations, Colombia’s post-conflict development and conflict-affected zones, revealing a troubling disconnect between ecological vulnerability and the territories targeted for rural development investment.

The author is careful to frame the work as a decision-support framework rather than a prescriptive blueprint. The maps are visual representations of underlying models, subject to uneven sampling effort, equal weighting assumptions, and the limitations of one-kilometer climate data, and the study explicitly does not analyze the economic, cultural, or governance drivers of land-use change. Because many páramos lie near Indigenous territories, the study notes that any application of its results should proceed through participatory, rights-based processes consistent with the UN Declaration on the Rights of Indigenous Peoples. Still, the core message is unambiguous and urgent: the transition zones where farms meet sky islands are where biodiversity loss is happening fastest, and the Eastern Cordillera complexes of Santurbán-Berlín, Almorzadero, and Guantiva-La Rusia, where evolutionary uniqueness and agricultural pressure converge, deserve to be at the very top of Colombia’s conservation agenda. As climate change pushes both crops and endemic plants ever higher up the mountains, the window for proactive protection of these water towers of the Andes is narrowing fast.

Subject of Research: Integrating biodiversity, biogeography, and agricultural land-use data to prioritize conservation of six strategic páramo complexes in the Colombian Andes

Article Title: Integrating biodiversity, biogeography, and agricultural data to prioritize conservation: a case study of six strategic páramo complexes in Colombia

Article References: Gonzalez-Orozco, C. E. (2026). Integrating biodiversity, biogeography, and agricultural data to prioritize conservation: a case study of six strategic páramo complexes in Colombia. Discover Conservation, 3(1), Article 7. https://doi.org/10.1007/s44353-026-00077-z

Image Credits: AI Generated

DOI: 10.1007/s44353-026-00077-z

Keywords: páramos, Colombia, biodiversity conservation, endemism, Espeletia, agricultural expansion, phylogenetic diversity, biogeography, geodiversity, Andes, conservation prioritization, sky islands