Publications
On the variation, distribution and evolutionary history of Myotis armiensis (Chiroptera, Vespertilionidae) along Neotropical mountain ranges
A recent study reveals that the bat species Myotis armiensis, found in the Talamanca Range-La Amistad Reserves and other Neotropical mountain ranges, may comprise two distinct evolutionary lineages. Using a combination of morphological analysis, genetic sequencing (cytochrome b), and ecological niche modeling, researchers identified reciprocal monophyly between populations in Central America's Talamanca Cordillera and those in the South American Andes and Venezuela's Cordillera de La Costa. These populations exhibit significant genetic divergence (>3%) and morphometric variation, suggesting Pleistocene diversification driven by glacial cycles. While the findings hint at potential cryptic species, further research is needed to confirm their taxonomic status.
Annotated list of amphibians and reptiles of Costa Rica: The role of the Museum of Zoology in cataloging the country’s herpetological diversity
Costa Rica's herpetological diversity, comprising 221 amphibian and 257 reptile species, has been significantly documented through the efforts of the Museum of Zoology at the University of Costa Rica (MZUCR). This collection, one of the most comprehensive in the country, holds over 24,000 cataloged specimens, including critical holotypes and paratypes for 47 species. The study updates the list of native species, addressing taxonomic controversies, while also tracing the history of the MZUCR's collection since its inception in the 1960s. Despite extensive sampling, gaps remain in the northern lowlands and Caribbean foothills of the Talamanca Range, indicating ongoing exploration needs. The research underscores the museum's pivotal role in advancing biological knowledge and taxonomic decisions for Costa Rica's herpetofauna.
Flora of high mountain tropical peatlands: threats and management measures, Talamanca Range, Costa Rica
Tropical peatlands in the Talamanca Range-La Amistad Reserves, particularly those outside protected areas, exhibit significantly lower biological diversity due to edge effects and proximity to agro-productive activities or the Inter-American Highway. In contrast, peatlands within protected zones like Salsipuedes and Cerro Paramillo show higher diversity, featuring genera such as Blechnum, Puya, Chusquea, Myrsine, Vaccinium, and Sphagnum. The study, which analyzed five peat bogs at altitudes of 2,400–3,100 meters using field sampling and a Floristic Value Index (IVF), highlights these ecosystems as critical components of the Mesoamerican hotspot, not only for biodiversity but also as sensitive indicators of human impact and climate change. The research underscores the vulnerability of these fragile formations to anthropogenic pressures.
Land of giants: two new pachycaul Monstera (Araceae, Monsteroideae, Monstereae) from Panama
Two new giant species of pachycaul Monstera, M. corana and M. colossica, have been discovered in the cloud forests of Panama's Talamanca Range-La Amistad Reserves, a biodiversity hotspot characterized by high humidity and volcanic soils. These discoveries expand the known diversity of the genus Monstera, which is notable for its large leaf and inflorescence sizes. The study provides detailed morphological descriptions, field observations, distribution maps, and comparisons with related taxa, contributing to our understanding of this ecologically significant region. The findings highlight the Talamanca Range as a critical area for plant species discovery and conservation.
Los pueblos indígenas frente a la conservación moderna en Costa Rica (1970-2020). Un acercamiento desde la sociología crítica del poder
Indigenous peoples in Costa Rica's Talamanca Range-La Amistad Reserves face complex relationships with modern conservation efforts, marked by both cooperation and conflict. This study reveals that while protected areas like La Amistad National Park aim to preserve biodiversity, they often clash with the cultural and territorial rights of indigenous groups such as Bribri, Cabecar, Brunka, Maleku, and Chorotega. Using a critical sociological approach, the research analyzes primary and secondary documents from archives, including texts by indigenous movements, to synthesize key findings on environmental and political histories (1970-2020). It highlights how power dynamics shape conservation policies, offering insights into the challenges of balancing ecological preservation with indigenous sovereignty.
Seismic Evidence for Cocos Slab Tearing and Nazca Slab Emplacement in the Southern Costa Rican Subduction Zone
A flat interface at 40–60 km depth beneath the Talamanca Range, identified through seismic receiver function analysis, reveals the stagnation of the Nazca plate since approximately 8 million years ago. This geological feature likely blocked melt upwelling, explaining the cessation of arc volcanism in the region while coinciding with the later uplift of the Talamanca Range due to subduction of the Cocos Ridge. The study employed a refined Dip Direction Searching method on teleseismic waveforms from 17 broadband stations, imaging a northeast-dipping Moho interface of the Cocos slab that may have undergone tearing, providing critical insights into the dynamic processes governing subduction zone volcanism and tectonics.
Three new species of Pleurothallis (Orchidaceae) from Costa Rica and Panama, with a note on asexual reproduction by prolification in Pleurothallidinae
Researchers have identified three new species of Pleurothallis orchids—P. matrisilvae, P. pridgeoniana, and P. winkeliana—from the Talamanca Range-La Amistad Reserves in Costa Rica and Panama, distinguished by their prolific vegetative growth and unique morphological traits. These species exhibit asexual reproduction through prolification, where new ramicauls develop from floral meristems, either constitutively or under stress conditions. P. matrisilvae resembles P. bothros but features thinner ramicauls, longer flower segments, and black flecks on reproductive structures. P. pridgeoniana, similar to P. vinealis, is characterized by smaller yellow flowers with rose-purple suffusion and a triangular-ovate lip without a central sulcus. P. winkeliana mirrors P. longipetala but differs in broader, cordate leaves and a pendent lip perpendicular to the column. The study highlights the diversity of Pleurothallidinae orchids in high-altitude, humid environments.
A Rare and Extraordinary New Species of Trichopilia from Costa Rica
Researchers have discovered Trichopilia gustavoi, a rare and extraordinary new species of orchid within the globally significant UNESCO World Heritage Site, Talamanca Range-La Amistad Reserves. Known only from its type locality—a pristine forest in Finca Las Alturas de Cotón near La Amistad National Park—this species is distinguished by its falcate petals, boat-shaped lip with scattered verrucae, and a sigmoid column. Morphologically similar to T. marginata, T. gustavoi represents an exceptional addition to the orchid genus, honoring University of Costa Rica Rector Gustavo Gutiérrez Espeleta for his contributions to biodiversity research and conservation.
Bird and mammal roadkill patterns and associated factors on a tropical mountain area: the Interamerican Highway, Cerro de la Muerte, Costa Rica
Researchers identified 34 collision hotspots for birds and mammals along a 45 km section of the Interamerican Highway in Costa Rica, with seven segments experiencing both bird and mammal roadkill. The study found that bird collisions were influenced by forest area at a 150 m scale, distance to rivers, and road sinuosity, while mammal collisions showed no clear association with evaluated variables. Over 8 months, 148 carcasses from 21 species were recorded, highlighting critical zones for mitigation efforts. This study advances understanding of roadkill patterns in tropical mountain areas, providing actionable insights for conservation strategies on the UNESCO-listed Talamanca Range-La Amistad Reserves.
Conservation status of three rare endemic Phaseolus bean (Leguminosae, Phaseoleae) species of Costa Rica
Three rare and endemic Phaseolus bean species—P. albicarminus, P. angucianae, and P. hygrophilus—found in the Talamanca Range-La Amistad Reserves, are classified as Endangered (EN) due to their limited distribution and rapid habitat loss from deforestation for coffee plantations or pastures. Only eleven populations exist across the Talamanca and Fila Cruces mountain ranges, outside protected areas. The study, conducted between 2003–2018 using field observations and satellite imagery, highlights urgent conservation concerns for these species, critical for future plant breeding efforts.
Distribution and habitat use patterns of the endangered Central American clouded oncilla (Leopardus pardinoides oncilla) in Costa Rica
Central American clouded oncillas (Leopardus pardinoides oncilla) primarily inhabit high-elevation, dense cloud forests near permanent water sources, likely due to the abundance of prey and favorable structural conditions. A study using camera traps and occupancy modeling in Costa Rica's Talamanca Range-La Amistad Reserves identified environmental factors—such as tree density and proximity to water—as key drivers of their habitat selection. Spatial predictions highlighted two critical conservation areas: the Caribbean slope of the Talamanca Mountains and the Arenal-Monteverde forest complex, where threat mitigation and monitoring are urgently needed. The research underscores the species' vulnerability to climate change and mesopredator pressure, emphasizing the need for targeted conservation efforts.
Endemism Centres of the Five Richest Vascular Epiphyte Families in the Neotropics
Researchers have identified key endemism centers for vascular epiphytes, focusing on the five most species-rich families—Orchidaceae, Bromeliaceae, Araceae, Piperaceae, and Polypodiaceae—in the neotropical region. These areas, including Paramo, Cauca, Guatuso-Talamanca, Atlantic, Yungas, and Puntarenas-Chiriqui biogeographic provinces, exhibit high levels of endemic species, particularly within the Talamanca Range-La Amistad Reserves / La Amistad National Park. The study analyzed geographic ranges for 11,446 epiphyte species, revealing that regions with greater epiphyte richness tend to have a higher proportion of endemic species, though composition varies significantly among families. Orchidaceae, representing 71% of the analyzed species, largely shaped the overall distribution pattern. The findings underscore the importance of prioritizing these endemism centers for conservation efforts to protect unique and threatened epiphyte species.
Geographic risk assessment of Batrachochytrium salamandrivorans invasion in Costa Rica as a means of informing emergence management and mitigation
A significant geographic risk assessment reveals that approximately 23% of Costa Rica's landmass, including the Central and Talamanca mountain ranges, is highly suitable for the invasive fungal pathogen Batrachochytrium salamandrivorans (Bsal), threatening 37 salamander species. This study employed ecological niche modeling combined with biodiversity and tourist visitation data to identify eight protected areas at greatest risk due to their high biodiversity, frequent human activity, and favorable habitat conditions for Bsal. The findings underscore the importance of proactive monitoring using remotely-sensed data and ecological niche modeling to target surveillance efforts and mitigate potential outbreaks effectively.
Light drives nitrogen fixation in tropical montane cloud forests in Costa Rica
Light significantly enhances nitrogen fixation by bryophytes in tropical montane cloud forests, with rates 57 times higher on epiphytic bryophytes compared to litter and 270 times greater than in soil. This process is more pronounced in secondary forests, suggesting that increased light exposure due to disturbance may accelerate ecosystem recovery. The study measured nitrogen fixation across primary and secondary cloud forests in Costa Rica's Talamanca Range-La Amistad Reserves, highlighting the critical role of light in this nitrogen cycle process.
Taxonomic assessment of the Bolitoglossa (Eladinea) subgenus (Caudata: Plethodontidae) with the description of two new species from the Cordillera de Talamanca, Costa Rica
A taxonomic assessment of the Bolitoglossa (Eladinea) subgenus in Costa Rica's Cordillera de Talamanca reveals seven species, including two newly described. This expands the known diversity of miniature salamanders, with one discovered on Cerro Utyum and another from Valle del Silencio. The study redefines Bolitoglossa robinsoni and updates the distributional range and body size data for Bolitoglossa bramei. Fieldwork at key locations, including Tapantí and mountain summits, was crucial in identifying these species, many of which were previously documented from fewer than five specimens.
Exploring how disturbance and light availability shape the elevation ranges of multiple mountain tree and shrub species in the tropics
Disturbance and light availability are critical factors shaping the elevation ranges of tropical mountain tree and shrub species, according to a study in the Talamanca Range-La Amistad Reserves. The research found that canopy openings created by disturbances provide essential habitat for high-elevation species, enabling them to persist under warmer conditions. Using distance sampling transects along a 1400 m elevation range and density surface models, the study analyzed nine species, revealing context-dependent light requirements—some shifted from shade tolerance to strict light demand across their elevation range, while others thrived in shaded, crowded conditions. These findings highlight the importance of considering disturbance dynamics in conservation strategies for high-elevation plant species.
Habitat use, richness, and abundance of native mice in the highlands of the Talamanca mountain range, Costa Rica
Researchers found that native mice, particularly the species Peromyscus nudipes, are significantly more abundant and diverse in montane forests compared to paramo habitats within the Talamanca Range-La Amistad Reserves. The study, conducted across four microhabitats—paramo-bush, paramo-Chusquea, montane forest-bush, and montane forest-Chusquea—revealed that the more complex vegetation structure of montane forests provides better conditions for mice, offering greater diversity in food resources and shelters. P. nudipes accounted for 85% of all captures, highlighting its dominance in these ecosystems. The findings underscore the importance of habitat structure in shaping rodent abundance and richness, contributing valuable insights to conservation efforts in biodiversity hotspots like Costa Rica's highlands.
Key for Identification of Bumblebee Queens from Costa Rica (Apidae: Apinae: Bombini)
A new dichotomous key enables the identification of bumblebee queens from Costa Rica, resolving long-standing challenges in distinguishing between species with nearly identical coloration. The study reveals that Bombus ephippiatus and B. digressus—previously indistinguishable—can be differentiated by jaw characteristics alone. It also clarifies distribution patterns, showing that B. weisi, B. digressus, and B. mexicanus have more restricted ranges compared to B. pullatus, B. ephippiatus, and B. volucelloides. Additionally, the research corrects a taxonomic confusion, confirming that B. melaleucus—previously thought to be present in Costa Rica—is actually confined to South America, though its potential occurrence in southern Pacific regions like La Amistad International Park remains plausible.
Vulnerability of elevation-restricted endemic birds of the Cordillera de Talamanca (Costa Rica and Panama) to climate change
Endemic birds in the Cordillera de Talamanca, a global biodiversity hotspot spanning Costa Rica and Panama, face significant range contractions by 2070 due to climate change. Using eBird community science data and Maxent modeling, researchers predicted that these elevation-restricted species could lose 15% to 40% of their habitat under moderate to severe climate scenarios (RCP 2.6 to RCP 8.5). Most species' current ranges are already within protected areas, highlighting the growing importance of conservation efforts in these regions. The study underscores urgent needs for better population monitoring and vigilance to mitigate threats to these vulnerable species.
Exploring Dissolved Organic Carbon Variations in a High Elevation Tropical Peatland Ecosystem: Cerro de la Muerte, Costa Rica
High-elevation tropical peatlands, often overlooked due to their fragmented nature, exhibit significant variations in dissolved organic carbon (DOC) that contribute to understanding broader carbon dynamics. A study in the Talamanca Range-La Amistad Reserves, Costa Rica, revealed DOC concentrations ranging from 0.2 to 47.0 mg/L across an altitudinal gradient of 2,400–3,100 m a.s.l., with a notable prevalence of recalcitrant soil-derived DOM. The research employed optical properties, including fluorescence peak ratios and humification indexes, to assess DOM sources and decomposition processes during the rainy season. Findings indicated a mixture of soil organic matter, microbial CO2, and minimal DIC from bacterial activity, underscoring the complex carbon cycling in these ecosystems. This baseline data highlights the potential for high-elevation peatlands to inform tropical carbon dynamics, offering critical insights for conservation efforts.
Genetic diversity and phylogeographic patterns of the dioecious palmChamaedorea tepejilote(Arecaceae) in Costa Rica: the role of mountain ranges and possible refugia
A novel phylogeographic pattern of gene flow between Caribbean and Pacific populations of the understory palm Chamaedorea tepejilote was uncovered, suggesting historical connectivity through the southern Talamanca Mountain range in Panama. This challenges previous assumptions about dispersal pathways in Lower Central America (LCA). The study used nuclear SSR and chloroplast DNA markers to analyze genetic diversity across 18 populations in Costa Rica, revealing moderate to high nuclear genetic diversity but eroded cytoplasmic diversity, likely due to habitat fragmentation and population declines. High-elevation mountain ranges acted as significant barriers to gene flow, though low-elevation passes allowed connectivity. The findings highlight the role of mountain ranges in shaping Neotropical plant phylogeography and underscore the importance of this first phylogeographic study for the genus Chamaedorea.
Geomorphic and exhumational response of the Central American Volcanic Arc to Cocos Ridge subduction
A new study reveals that the geomorphic and exhumational evolution of the Talamanca Range-La Amistad Reserves, part of the extinct Central American Volcanic Arc, is intricately linked to the subduction of the Cocos Ridge. Researchers identified a relict erosional landscape at high elevations, characterized by low relief and shallow plutonic rocks, which provides critical insights into the range's cooling and erosional history from the late Miocene to present. Analysis of river longitudinal profiles and knickzones suggests that rock uplift during the growth of the Cordillera de Talamanca was no greater than approximately 2 kilometers. Low-temperature thermochronometry data, including apatite (U-Th)/He and fission track analyses on Mt. Chirripó, indicate that rapid cooling in the late Miocene was due to secular cooling rather than exhumation. The study concludes that significant geomorphic features such as rapid incision and differential rock uplift are relatively young, associated with the onset of Cocos Ridge subduction less than 3 million years ago. This finding separates the cessation of arc volcanism in the late Miocene from the initiation of ridge collision, reflecting recent changes in the plate boundary system.
Magmatic and Tectonic Domains of Central Costa Rica and the Irazú‐Turrialba Volcanic Complex Revealed by Ambient Noise Tomography
A shared magma reservoir at 5–7 km depth beneath the Irazú-Turrialba Volcanic Complex, fed by a sub-vertical conduit from at least 12 km depth, has been revealed through ambient noise tomography. This study provides new insights into the plumbing system of one of Central America's most active volcanic twin systems, located at the transition between the Central American Volcanic Arc and the Talamanca Cordillera. Researchers deployed a temporary seismic network to analyze Rayleigh wave group-velocity dispersion curves, uncovering distinct magmatic reservoirs beneath each volcanic edifice. The findings enhance understanding of the spatial relationship between tectonic features and magma distribution in this critical geological region.
Mapping Mountain Landforms and Its Dynamics: Study Cases in Tropical Environments
A novel methodological framework for geomorphological mapping in high mountain areas, particularly in tropical environments, has been developed and applied to two case studies: Cerro Chirripó in the Talamanca Range and the Reserva Biológica Alberto Manuel Brenes in the Central Volcanic Range. The study emphasizes the importance of combining classical and digital mapping techniques with advanced technologies like UAVs and GIS to accurately capture landform dynamics, crucial for water security, natural hazard assessment, and ecosystem conservation. High-resolution cartography, achieved through this approach, provides critical insights into glacier and fluvial geomorphology in warming environments, offering a scalable model for global mountainous regions.
Parasitic fauna of bats from Costa Rica
Research on the parasitic fauna of bats from Costa Rica's Talamanca Range-La Amistad Reserves reveals significant findings about pathogen spread and zoonotic potential. The study identified a diverse range of ectoparasites, including mites, flies, and ticks, with Rickettsia spp. detected in an immature tick, suggesting a link to spotted fever group pathogens. Gastrointestinal parasites such as Giardia spp., Cryptosporidium spp., and Eimeria spp. were also found, highlighting bats' role as potential spreaders of diseases. The study sampled 113 bats across two sites, using morphological and molecular identification techniques to analyze ectoparasites and fecal samples for pathogens. These findings underscore the need for further investigation into the pathogenic potential of parasites in neotropical bat populations.
Acorn characteristics, seed germination, seedling development, and leaf traits of three oak species from Talamanca, Costa Rica1
Research on three dominant oak species in Costa Rica's Talamanca Range reveals significant interspecific differences in acorn characteristics, seed germination, and seedling traits along an elevation gradient. Quercus costaricensis, found at higher elevations (2,000–3,200 m), produces larger acorns with higher viability and germination rates compared to Quercus salicifolia and Quercus bumelioides. Despite smaller acorn size in the latter species, their seeds are not less prone to germinate. Seedlings of all species exhibit rapid development of leafy crowns and adventitious root systems, facilitating resource acquisition beyond cotyledons. Notably, Q. costaricensis seedlings have smaller, darker, and thicker leaves, though no differences in leaf mass per area were observed among species. These findings underscore the importance of seed size and environmental heterogeneity in niche segregation and species distribution along elevation gradients.
Altitudinal range extension of Long-tailed Singing Mouse, Scotinomys xerampelinus (Bangs, 1902) (Rodentia, Cricetidae), in Chirripó National Park, Costa Rica
Researchers have documented the Long-tailed Singing Mouse (Scotinomys xerampelinus) at an unprecedented elevation of 3820 meters on Cerro Chirripó, Costa Rica, extending its known altitudinal range by 420 meters. This discovery suggests either historical gaps in survey data or a potential upslope shift driven by climate change, as rising temperatures may be pushing species to higher elevations—a trend observed in other Costa Rican vertebrates. The study relied on field observations within Chirripó National Park, part of the Talamanca Range-La Amistad Reserves.
Pleurothyrium amissum (Lauraceae), a New Endemic Tree from the Talamanca Montane Forest in Costa Rica
A new endemic tree species, Pleurothyrium amissum, has been discovered in the highland oak forests of Costa Rica's Talamanca Range. This species, belonging to the Lauraceae family, is distinguished from its close relative, P. pauciflorum, by notable differences in height, leaf size, inflorescence structure, flower color, and habitat preferences. The discovery was facilitated through detailed morphological analysis, including photographs, a distribution map, and a taxonomic key for Costa Rican Pleurothyrium species. This finding underscores the rich biodiversity of the Talamanca Montane Forest and contributes to our understanding of plant diversity in this ecologically significant region.
Phaseolus albicarminus (Leguminosae, Phaseoleae), a new wild bean species from the subhumid forests of southern central Costa Rica
Researchers have identified Phaseolus albicarminus, a new wild bean species endemic to the subhumid forests of southern central Costa Rica. This discovery was made during a survey for populations of wild common beans on the slopes of Cerros Llano Bonito within the Talamanca Range-La Amistad Reserves / La Amistad National Park. The new species is distinguished by unique morphological features such as short pseudoracemes with four small deltoid primary bracts, white wings contrasting with carmine purple inner faces of the standard, and smoothly curved pods with prow-shaped beaks. It differs significantly from closely related species like P. hygrophilus and P. angucianae in traits such as bract shape, bracteole size, calyx lobe structure, and pod dorsal suture. With only three known populations confined to a small area, the conservation status of P. albicarminus warrants immediate monitoring. The species is tentatively assigned to the section Brevilegumeni, which appears to be well-represented in Costa Rica.
Short-term Measures to Avoid Retaliatory Killing of a Tapir (Tapirus bairdii ) during a Case of Human Conflict at La Amistad Biosphere Reserve, Costa Rica
A successful short-term intervention using salt-licks and community engagement effectively prevented retaliatory killing of a Baird’s tapir (Tapirus bairdii) involved in crop-raiding within the La Amistad Biosphere Reserve, Costa Rica. The study highlights the potential of rapid response strategies—combining on-site interviews with landowners and alternative solutions—to mitigate human-wildlife conflict without lethal outcomes. This approach offers a practical model for conservation efforts where tapir-human interactions pose risks to both species. The findings underscore the importance of proactive measures in reducing retaliatory killings, a critical issue identified in global tapir conservation planning.
Species distribution models predict the geographic expansion of an enzootic amphibian pathogen
A significant geographic expansion of the enzootic amphibian pathogen Batrachochytrium dendrobatidis (Bd) has been identified in Costa Rica, with its distribution increasing by 60% since early 2000s estimates. This expansion includes highlands and dry lowlands previously considered unsuitable for Bd. The study, which combined histological and PCR detection methods across 451 Bd-positive records from 34 localities, revealed that Bd is widespread in protected lands (80%) and within regions of high amphibian richness and endemism. It also highlighted deficiencies in opportunistic sampling, particularly in the Talamanca Range, Nicoya Peninsula, and northern lowlands, while PCR detection proved more effective in identifying Bd hotspots on the Caribbean side. These findings enhance understanding of disease spread during enzootics and can guide mitigation efforts for future outbreaks.
Bush Dogs in Central America: Recent Range Expansion, Cryptic Distribution, or Both?
Recent observations of bush dogs (Speothos venaticus) in east-central and southeastern Costa Rica, including Barbilla National Park and La Amistad International Park, suggest a potential range expansion or previously underestimated distribution. This small, pack-hunting neotropical canid has historically been considered rare, with its range possibly extending up to 120 km north-northwest in the Talamanca Mountains at elevations reaching 2,119 meters. The study highlights challenges in documenting their current and future distribution due to their inherently low density. Researchers used repeated observations to assess these findings, contributing new insights into the ecology and conservation of this elusive species within UNESCO World Heritage Sites.
Description of Onthophagus humboldti and Uroxys bonplandi, two new scarab beetles (Coleoptera, Scarabaeidae, Scarabaeinae) from Costa Rica, with notes on tropical mountain brachyptery and endemicity
Researchers have identified two new endemic scarab beetle species, Onthophagus humboldti and Uroxys bonplandi, from Costa Rica's Talamanca Range-La Amistad Reserves. Notably, O. humboldti is the tenth brachypterous (short-winged) species in the genus Onthophagus globally, showcasing extreme brachyptery within this group. The study also reveals that tropical mountain ranges like the Cordillera de Talamanca exhibit higher levels of endemism and brachyptery than lowland rainforests, challenging conventional beliefs. By analyzing mitochondrial DNA, the research supports the distinctiveness of two closely related Onthophagus species groups: O. dicranius and O. clypeatus. Additionally, a biogeographical model suggests that stable environments in deeply incised valleys during the Last Glacial Maximum may have promoted brachyptery in scarab beetles.
Drivers of tropical rainforest composition and alpha diversity patterns over a 2,520 m altitudinal gradient
A study on the Talamanca Range-La Amistad Reserves reveals two distinct forest compositional zones—lowland (430–1,120 m asl) and montane (>2,150 m asl)—with a transitional zone (1,400–1,600 m asl) where lowland tropical and montane holarctic species coexist. Montane forests exhibit significantly lower alpha diversity, strongly influenced by altitude, soil, and spatial factors. Researchers analyzed 32 undisturbed rainforest plots using NMS ordination and linear regressions to assess the relationship between forest composition, alpha diversity metrics, and environmental variables. The findings suggest that vegetation and soil respond to altitude as an integrated system, challenging niche assembly models.
A New Anthurium from La Amistad International Park (PILA), Panama-Costa Rica Border
Researchers have identified and described a new species of Anthurium, A. jorgemendietanum, endemic to La Amistad International Park (PILA), a binational UNESCO World Heritage Site spanning Panama and Costa Rica. This discovery contributes to the rich biodiversity of PILA, which hosts 62 known Anthurium species, six of which are endemic. The study provides detailed morphological descriptions, photographs, and illustrations of the new species, while also discussing its taxonomic affinities within the genus. La Amistad International Park, covering 401,000 hectares, is notable for its diverse vascular flora, including 3,046 species and 114 Araceae species, underscoring its ecological significance.
Deep divergence of Red-crowned Ant Tanager ( Habia rubica : Cardinalidae), a multilocus phylogenetic analysis with emphasis in Mesoamerica
A robust phylogenetic analysis reveals that the Red-crowned Ant Tanager (Habia rubica) exhibits deep genetic divergence, with seven distinct phylogroups corresponding to major geographical discontinuities such as the Isthmus of Tehuantepec, Talamanca Cordillera, and Isthmus of Panama. These findings suggest a complex history of diversification in this polytypic species, particularly in its northern distribution, where at least seven well-supported lineages may represent distinct species. The study used multilocus analyses of five molecular markers (ND2, ACOI-I9, MUSK, FGB-I5, and ODC) across the species' range from Central Mexico to South America, providing a detailed hypothesis for its evolutionary trajectory.
Effect of barriers and distance on song, genetic, and morphological divergence in the highland endemic Timberline Wren (Thryorchilus browni, Troglodytidae)
Mountain passes and distance significantly reduce gene flow between populations of the Timberline Wren (Thryorchilus browni), leading to notable divergence in genetic, vocal, and morphological traits. Researchers analyzed four Costa Rican populations using microsatellites and song recordings, revealing that a lowland mountain pass caused the greatest differences—likely due to reduced gene flow. Cultural drift and female assortative mating, where females prefer songs from their own population, further accentuated these effects. This pattern of divergence, observed over smaller scales than previously documented in Neotropical highland birds, underscores how geographic barriers and limited movement shape evolution in highland species with restricted distributions.
Are landscape attributes a useful shortcut for classifying vegetation in the tropics? A case study of La Amistad International Park
Research in La Amistad International Park reveals that river catchment, combined with elevation and annual mean temperature, effectively explains variation in tropical plant species composition. Unlike traditional elevation-based classifications, which often dominate in the tropics, this study found distinct vegetation assemblages only at high-elevation oak forests and Páramo zones. While beta diversity did not significantly differ across mid-elevation plots, it varied between river catchments, suggesting that river catchment could serve as a useful alternative for classifying tropical forest assemblages in conservation settings. The analysis utilized floristic data from 141 plots spanning an elevation gradient of 130 to 3200 meters above sea level.
Impact of Cocos Ridge (Central America) subduction on the forearc drainage system
Subducting the Cocos Ridge beneath Central America deflects rivers away from its crest, shaping the drainage patterns of the Talamanca Range-La Amistad Reserves/La Amistad National Park. This study reveals that such subduction influences forearc drainage systems, with rivers above the ridge flanks diverging while those over its broad crest show minimal deflection. The modern drainage system in Costa Rica and Panama suggests the Cocos Ridge has been subducting for at least 1.8 million years. Researchers used a combination of three-dimensional finite-element modeling of ridge subduction and landscape evolution models to demonstrate how subducting topographic highs alter drainage patterns, providing insights into the onset and history of ridge subduction.
Measuring conservation success beyond the traditional biological criteria: the case of conservation projects in C osta R ica, M ekong V alley, and C ameroon
Conservation success cannot be measured solely by biological criteria such as species diversity or protected area size. A holistic approach, incorporating environmental, political, social, and conflict pressures, is necessary to accurately assess conservation outcomes. Using a proposed interdisciplinary rubric, this study evaluates conservation projects in Costa Rica's Talamanca Range-La Amistad Reserves, the Mekong Valley, and Cameroon. Findings reveal that traditional biological metrics often overlook critical factors influencing success or failure. For instance, Costa Rica's Guanacaste and Talamanca national parks are rated 'moderately low' under this new framework, while Mekong Valley projects range from 'low' to 'moderately low,' and Cameroon's efforts are predominantly rated 'low' or 'very low.' The study concludes that global conservation strategies must shift from a narrow biological focus to a broader, interdisciplinary approach to achieve meaningful success.
A cryptic palm-pitviper species (Squamata: Viperidae: Bothriechis) from the Costa Rican highlands, with notes on the variation within B. nigroviridis
A new cryptic species of palm-pitviper, Bothriechis nubestris, has been identified within the previously recognized B. nigroviridis complex in the Talamanca Range-La Amistad Reserves/La Amistad National Park (UNESCO World Heritage Site). Genetic and morphological analyses revealed two deeply divergent lineages: one restricted to the northern and central Cordillera Talamanca, and another widespread across the Central, Tilarán, and Talamanca Cordilleras. These lineages exhibit distinct morphological traits, including previously unrecognized differences in scale characters. The study sheds light on the biogeographic history of Bothriechis, contributing to our understanding of speciation in Middle American cloud forests—a region renowned for its biodiversity and endemic species.
Complex niche divergence underlies lineage diversification in Oophaga poison frogs
Oophaga poison frogs, native to the Talamanca Range-La Amistad Reserves and La Amistad National Park, exhibit complex niche divergence patterns that have driven their speciation. The study reveals that these frogs originated in Central America before dispersing into South America post-Panama Isthmus closure, with both clades converging on similar geographical distributions and climatic niches. Sister taxa within each clade display parapatric distributions along elevational gradients, suggesting divergence along continuous ecological gradients. The research used multi-locus gene genealogies, species phylogenetic methods (MDC and *beast), and environmental niche modeling to reconstruct their phylogeny and test the role of geographical isolation, climatic niche divergence, and altitudinal gradients. Notably, significant shifts in climatic niches were observed post-dating the final elevation of the Talamanca Range and northern Andes, indicating that speciation along structured landscapes has been a primary evolutionary force.
The Protection of Forest Biodiversity can Conflict with Food Access for Indigenous People
International protected area (PA) policies, while recognizing Indigenous rights, often conflict with traditional food access for Indigenous communities. A study at La Amistad Biosphere Reserve, Costa Rica, found that PA regulations restricting shifting agriculture and hunting negatively impact the health, nutrition, cultural identity, and social cohesion of the Bribri people. These restrictions also affect the transmission of cultural teachings to youth and the relationship with non-human beings. The research analyzed land management documents and engaged with the Bribri community to identify these impacts. To mitigate such conflicts, the study proposes integrating a right-to-food framework into PA management, allowing communities to define sustainable harvesting practices, and ensuring clear communication of regulations to resource users.
Unveiling the Hidden Bat Diversity of a Neotropical Montane Forest
Research in the Talamanca Range-La Amistad Reserves reveals significant hidden bat diversity, with mitochondrial DNA analysis uncovering highly divergent lineages (> 9% COI dissimilarity) in species like Myotis oxyotus and Hylonycteris underwoodi, suggesting high endemism. The study, conducted through a 15-night sampling campaign capturing 90 bats across 8 species, used phylogenetic methods to compare populations with those from other regions. Findings indicate that montane ecosystems in Central America may harbor previously unrecognized bat diversity but face severe extinction risks due to climate change, particularly in isolated systems like the Talamanca Range.
First record of the myxomycete genus Colloderma in Central America
A groundbreaking discovery has been made in the Talamanca Range-La Amistad Reserves, with the first recorded presence of the myxomycete genus Colloderma and its species, Colloderma oculatum, in Central America. This finding, documented during a 2014 expedition in Costa Rica's high elevations, challenges traditional ecological classifications by identifying a temperate-associated species in what is typically considered a tropical environment. The discovery expands the known biodiversity of Costa Rican myxomycetes to 213 species, according to the latest checklist. Researchers analyzed the geographical distribution and ecology of this unique species, providing insights into its habitat preferences and potential implications for conservation efforts in UNESCO World Heritage Sites.
Four new species of Symmerista Hübner, 1816 (Notodontidae, Nystaleinae) from Costa Rica
Researchers have identified four new species of moths belonging to the genus Symmerista (Notodontidae, Nystaleinae) from the cloud forests of the Talamanca Range-La Amistad Reserves in southern Costa Rica. These newly described species—Symmerista luisdiegogomezi, S. inbioi, S. minaei, and S. aura—contribute to the biodiversity documentation of this UNESCO World Heritage Site. Additionally, the study reclassifies Symmerista tlotzin as Elymiotis tlotzin, expanding our understanding of moth taxonomy in the region. The research combines morphological analysis with genetic barcoding to distinguish these species, providing a robust foundation for future studies on their ecology and conservation.
Sustainability Analysis in La Amistad Panama Biosphere Reserve
A sustainability analysis of the La Amistad Panama Biosphere Reserve reveals a modest overall progress of 56.3%, falling short of the globally accepted threshold of >70%. The study, using the Commission on Sustainable Development (CSD) indicators recommended by the United Nations, identifies environmental factors as the strongest performing category at 73.3%, while social and economic aspects lag significantly behind at 46.7% and 36.1%, respectively. This research introduces a universal sustainability assessment model applicable to all UNESCO Biosphere Reserves, leveraging well-established global indicators to evaluate progress across three key pillars: environment, society, and economy. The findings underscore the reserve's potential for improvement in social and economic dimensions while highlighting its environmental achievements.
Características geológicas de los depósitos de turba en Costa Rica (estudio preliminar).
A preliminary study reveals significant variations in peat deposits across three sites within Costa Rica's Talamanca Range-La Amistad Reserves. Peat in the Talamanca range, covering about 150 km², is characterized by its high ash content (21%), low water content (84%), and extensive bioturbation, with a notable bulk density of 0.22 g/cm³ and caloric value averaging 7700 BTU/lb, dry. In contrast, peat in Medio Queso de Upala exhibits the highest caloric values (8000 BTU/lb, dry), fixed carbon (30%), and ash content (22%) among sampled sites, interbedded with alluvial layers within a 70 km² flood plain. Meanwhile, El Silencio near Siquirres features peat exceeding 3.5 m in thickness, with lower bulk density (0.13 g/cm³), higher fiber content (53%), and a pH of 5.8. The study highlights the diverse geological characteristics of these peat deposits, providing insights into their potential uses and environmental significance.
Clarification of Zamia acuminata and a new Zamia species from Coclé Province, Panama
A new Zamia species, Zamia nana, is described from Coclé Province, Panama, resolving long-standing confusion surrounding Zamia acuminata. Research clarifies that Z. acuminata is a Costa Rican endemic restricted to the western Talamanca mountain range, distinct from plants previously misidentified in El Valle de Antón, Panama. The study leverages recently collected material and re-examination of the holotype to correct historical misidentifications and erroneous locality data. This taxonomic clarification enhances understanding of Zamia diversity in Central America.
Baird's tapir density in high elevation forests of the Talamanca region of Costa Rica
Researchers have identified the highest recorded density of Baird's tapir (Tapirus bairdii) in high-elevation forests, specifically within the Talamanca Range-La Amistad Reserves/La Amistad National Park. The study estimated a density of 2.93 individuals per square kilometer using camera-trap data and mark-recapture techniques, highlighting the potential importance of intermountain valleys as critical habitats for this endangered species. The findings suggest that such areas may serve as vital refuges, though further genetic and movement studies are needed to assess population connectivity and conservation strategies across lowland and highland regions in Costa Rica.
Cabécar – a Chibchan language of Costa Rica
Cabécar, an endangered Chibchan language spoken by the indigenous Cabécar people of Costa Rica's Talamanca Mountain Range, exhibits unique linguistic features that distinguish it from other languages. This study highlights its significance while noting a concerning trend: younger generations are increasingly adopting Spanish over their native tongue. The research delves into the distinctive characteristics of Cabécar, providing insights into its phonology, morphology, and syntax. By analyzing existing linguistic data, the study contributes to the documentation and preservation efforts for this endangered language, offering valuable perspectives on its structural complexity and cultural importance within the region.
Intrusive rocks
Limited progress has been made in understanding intrusive rocks in Central America since the 1970s, with knowledge of plutonic rocks lagging significantly behind that of volcanic rocks. Recent studies on the Talamanca Range in Costa Rica have provided some advances, though they remain less comprehensive than those for volcanic systems. This chapter synthesizes existing literature to highlight gaps and potential avenues for further research, focusing on the geological evolution of intrusive rocks in this region.
Ocelot density in the caribbean slope of the Talamanca region, Costa Rica
Researchers estimated the ocelot (Leopardus pardalis) population density for the first time on Costa Rica's Caribbean slope, specifically within the Talamanca-Caribbean Biological Corridor. Using camera-trapping and capture-recapture analysis, they found low densities ranging from 5.6 to 11.6 individuals per 100 km², depending on the model used (Mh or Mo). These findings suggest a small ocelot population in the region, highlighting its dependence on the corridor for long-term survival. The study provides critical baseline data for conservation efforts, emphasizing the need for protection of this UNESCO-listed area to sustain ocelot populations.
Respuesta ambiental en el Pacífico frente a la subducción de la dorsal asísmica de Cocos (Panamá y Costa Rica)
The subduction of the Aseismic Cocos Ridge (DAC) significantly altered marine environments along the Pacific coasts of Panama and Costa Rica, shaping the evolution of benthic communities. Research reveals that during the early Pliocene, oceanic islands with moderate upwelling existed in the Burica region before the Isthmus of Panama closed. The DAC's collision later uplifted the seafloor, transforming deep waters into shallow coastal areas and intensifying open-ocean upwelling while creating protected zones near Burica. This process led to the formation of coral reefs in the tropical Eastern Pacific. A second uplift event during the middle Pleistocene elevated the Talamanca Range, blocking trade winds and further optimizing ecological conditions for marine life. The study reconstructed past benthic assemblages using Neogene fossil formations and modern dredge collections, analyzed via principal component analysis to compare paleoecological conditions with contemporary data.
The Fern GenusPolystichum(Dryopteridaceae) in Costa Rica1
Costa Rica is home to 12 species of the taxonomically challenging fern genus Polystichum, including three allopolyploids. This study provides a taxonomic identification guide for these species, focusing on key morphological characters such as petiole and pinna-rachis scales, ultimate segment shape, and indusium. The research also evaluates the distribution patterns of the genus in the Neotropics, revealing that while five species are widespread across Tropical America, two extend to the southern range limits, and three—including two allopolyploids—are confined to Costa Rica and Panama. Additionally, the study lectotypifies three names: P. aculeatum var. flavidum, P. nudicaule, and P. opacum. The genus is predominantly found in high-elevation rainforests and páramos of the Cerro de Talamanca, highlighting its ecological preference for wetter montane regions.
A new species of Anolis (Squamata: Iguania: Dactyloidae) formerly referred to as A. pachypus from the Cordillera de Talamanca of western Panama and adjacent Costa Rica
Researchers have identified a new species of Anolis lizard, Anolis benedikti, previously misclassified as A. pachypus. This discovery was made through detailed morphological analysis of specimens from the Talamanca Range-La Amistad Reserves and adjacent areas in Panama and Costa Rica. The new species is distinguished by its unique male dewlap coloration—red with a yellow anterior margin—and pholidotic characteristics, setting it apart from closely related species like A. magnaphallus, A. pachypus, A. pseudopachypus, and A. tropidolepis. This finding contributes to the understanding of anoline diversity in the Cordillera de Talamanca, a region of significant biodiversity within UNESCO World Heritage Sites.
Bioestratigrafía del parche arrecifal de la Quebrada Brazo Seco, Plio-Pleistoceno, Limón, Costa Rica
A Plo-Pleistocene patch reef in the Talamanca Range-La Amistad Reserves, Costa Rica, reveals interrupted coral growth due to rapid sedimentation or uplifting. The study describes fossil content—including mollusks, corals, bryozoans, arthropods, and ichnofossils—from the Río Banano Formation, indicating a shallow marine environment with patch reefs. Overlying conglomerates of the Suretka Formation suggest fan delta deposits linked to the uplifting of the Talamanca Range. The research combines outcrop analysis and fossil data to reconstruct depositional conditions, providing insights into the geological history of this UNESCO World Heritage Site.
Evidencias de glaciación en el Valle del General (Costa Rica) durante el Pleistoceno Tardio
Research in the Talamanca Range-La Amistad Reserves reveals unexpected evidence of Late Pleistocene glaciation at elevations below 1000 meters, challenging previous assumptions that glacial activity in Costa Rica was confined to peaks above 3000 meters. The study identifies distinct glacial landforms, including U-shaped valleys, frontal and lateral moraines, megalithic deposits with striations, polished rock planes, and striae parallel to valleys along the San Rafael, San Pedro, and Peñas Blancas rivers. These features provide compelling evidence for significant glaciation during the Late Pleistocene in the Valle del General, suggesting that glacial processes extended to lower elevations than previously recognized.
New localities and altitudinal records for the snakes Oxyrhopus petolarius, Spilotes pullatus, and Urotheca fulviceps in Talamanca, Costa Rica
Researchers have documented new locality and altitudinal records for three snake species—Oxyrhopus petolarius, Spilotes pullatus, and Urotheca fulviceps—in the Talamanca Range-La Amistad Reserves of Costa Rica. These findings expand the known distribution ranges of these species within the Talamanca ecoregion, providing critical data for conservation planning and species assessments. The study relied on direct sightings to establish these records, contributing valuable insights into the biodiversity of this UNESCO World Heritage Site.
Regional and global conservation assessments for 200 vascular plant species from Costa Rica and Panama
A comprehensive conservation assessment of 200 vascular plant species from Costa Rica and Panama, with 52 receiving global assessments and 148 regional ones, reveals critical insights into the biodiversity of the Talamanca Range-La Amistad Reserves / La Amistad National Park. These species, identified as keystone for the reserve, include detailed taxonomic information, local names, uses, and maps illustrating their distribution. The study highlights significant threats to these species, providing a foundation for targeted conservation efforts. By combining regional and global assessments, this research offers a nuanced understanding of plant biodiversity and the urgent need for protective measures in one of the world's most ecologically significant regions.
Sección geológica del Pacífico al Atlántico a través de Costa Rica
A geological profile spanning Costa Rica, from the Osa Peninsula on the Pacific coast to Punta Cahuita on the Atlantic coast, reveals the distinct tectonic histories of two major basins: the Térraba and Talamanca basins. These basins accumulated over 5,000 meters of Tertiary sediments, forming a regressive megasequence. The Térraba basin exhibits compressive tectonics characterized by thrust scales and inverse faults, with subsidence in its backward part, while the Talamanca basin shows gravitational landslides in its sedimentary cover, leading to significant overlaps at the foot of the Talamanca mountain range on the coastal plain. This study provides a detailed reconstruction of the geological evolution of these basins, offering insights into their tectonic styles and sedimentary dynamics.
The steeply subducting edge of the Cocos Ridge: Evidence from receiver functions beneath the northern Talamanca Range, south‐central Costa Rica
A steeply dipping subducting slab, reaching depths of at least 70–100 km with an 80° angle, has been identified beneath the northern Talamanca Range in south-central Costa Rica. This finding, derived from receiver function analysis using broadband seismometers, challenges previous assumptions about the subduction zone's structure and suggests a possible transition to shallow-angle underthrusting. The study, which integrates data from local seismicity, tomography, and active seismic studies, reveals that the Cocos Plate slab maintains its steep dip even near the trench, indicating an ongoing reconfiguration of subduction dynamics in this region.
Where are the survivors? Tracking relictual populations of endangered frogs in Costa Rica
Researchers identified critical areas for the survival of endangered frog species in Costa Rica, particularly along the Pacific slopes of the Talamanca Range and Central Volcanic Cordillera. These regions, characterized by high humidity (2500–3500 mm mean annual precipitation) and elevations between 1300 and 2500 meters above sea level, serve as potential refugia for relictual populations of anurans. Using a Maximum Entropy Algorithm (Maxent), the study predicted suitable habitats for 17 endangered species and pinpointed approximately 240 km² where rediscovery efforts should focus. The analysis also revealed that around 0.5% of Costa Rica's territory, intersecting with conservation areas but avoiding high Bd risk zones, warrants exhaustive surveys. These findings highlight the importance of targeted fieldwork in undersurveyed regions to locate and protect relictual amphibian populations.
Imaging crustal structure in south central Costa Rica with receiver functions
A deeper Moho beneath the Talamanca Range, reaching ~50 km depth and indicating isostatic compensation, was identified using receiver functions from seismic data collected between 2005–2007. This study also revealed an intracrustal discontinuity at ~15 km depth, with distortions near active volcanic arcs (e.g., Irazu and Turrialba) and the Central Costa Rica Deformed Belt, suggesting tectonic influences. The research analyzed broadband seismometer data across southern Costa Rica to map crustal structure, confirming quartz-rich rock composition in the upper crust due to low vp/vs ratios (<1.7).
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