Diversidad y patrones de actividad de mamíferos silvestres medianos y grandes en la Cordillera de Talamanca, Costa Rica.

Introducción: La Cordillera de Talamanca en el sureste de Costa Rica, es una región prioritaria para la conservación, posee ecosistemas y especies poco conocidas. El estudio de mamíferos silvestres permite comprender la estructura y estado de conservación de los bosques tropicales: uno de los ecosistemas más diversos del planeta. Objetivo: Evaluar la riqueza, abundancia relativa y patrones de actividad de los mamíferos terrestres medianos y grandes en el Parque Internacional de La Amistad y el Corredor Biológico el Quetzal Tres Colinas. Métodos: Entre el 12 de julio del 2018 al 18 de abril del 2021, instalamos 18 estaciones de fototrampeo, cada una conformada por una cámara trampa y un atrayente olfativo. Resultados: Con un esfuerzo de muestreo de 15 335 días cámara trampa, obtuvimos 36 667 registros en los cuales detectamos 27 especies de mamíferos silvestres medianos y grandes; todas están en alguna categoría de riesgo nacional o internacional. Sciurus granatensis, Tapirus bairdii, Sylvilagus dicei y Mazama temama mostraron la distribución más amplia y la mayor abundancia relativa. Ateles geoffroyi, Cebus imitator y Microsciurus alfari tuvieron la menor abundancia y la distribución más restringida. Registramos cinco especies diurnas, seis nocturnas-crepusculares y 14 catemerales. Las especies únicas las detectamos en los pisos altitudinales Subalpino, Premontano y Montano bajo, los dos últimos registraron la mayor riqueza. Ocho especies mostraron fobia lunar, seis mostraron filia lunar y seis no mostraron afinidad al brillo lunar. Conclusión: Estas áreas protegen importantes poblaciones premontanas a subalpinas de mamíferos terrestres medianos y grandes, muchos catemerales o con fobia a la luna, y deben seguir siendo monitoreadas.

Recent findings of Isthmohyla pictipes (Anura: Hylidae) in Costa Rica: variation and implications for conservation

We report recent findings of Isthmohyla pictipes (Cope, 1875) in the Cordillera de Talamanca, Costa Rica, roughly two decades after it was last registered. We provide notes on microhabitat use, color variation, external morphology of adults and larvae, and geographic variation, and discuss some taxonomic characters employed to differentiate I. pictipes from I. tica (Starrett, 1966) and I. xanthosticta (Duellman, 1968). We also report fluorescence on the ventral surfaces of I. pictipes. Our findings are expected to shed light on the taxonomy of this species and should be useful in further population assessments and conservation plans.

Two new species of Monstera (Araceae: Monsteroideae) from Costa Rica

Two species of Monstera, apparently endemic to Costa Rica, are newly described and illustrated. Monstera juliusii occurs in the southern Costa Rican portion of the Cordillera de Talamanca at 1600–2250 m, and has been confused with M. standleyana in herbaria. Monstera monteverdensis occurs in the Guanacaste and Tilarán cordilleras, and the northwestern part of the Cordillera Central, at 500–2300 m, and has been confused with M. epipremnoides, M. lentii and M. lechleriana in herbaria. Phenology and suggested conservation categories according to the IUCN Red List criteria are indicated for both new taxa.

Vulnerability of Elevation-Restricted Endemic Birds of the Cordillera de Talamanca (Costa Rica and Panama) to Climate Change

ABSTRACTAnimals endemic to tropical mountains are known to be especially vulnerable to climate change. The Cordillera de Talamanca (Costa Rica and Panama) is a geographically isolated mountain chain and global biodiversity hotspot, home to more than 50 endemic bird species. We used eBird community science observations to predict the distributions of a suite of 48 of these endemic birds in 2006-2015, and in 2070, under four climate change scenarios. Species distributions were predicted using program Maxent, incorporating elevation, satellite derived habitat data, and WorldClim climate variables. Model fit, as assessed by Area under the Receiver Operator Curve (AUC) was very high for most species, ranging from 0.877 to 0.992 (mean of 0.94). We found that most species are predicted to undergo range contractions by 2070, with a mean of 15% under modest climate change (RCP 2.6) up to a mean of 40% under more severe climate change (RCP 8.5). Most of the current ranges of these species are within existing protected areas (average of 59% in 2006-2015), and with prospective range contractions, the importance of these protected areas is forecast to increase. We suggest that these predicted range declines should elevate conservation concerns for this suite of species, and vigilance, in the form of better population monitoring, is urgently needed.

Sistemas de compensación de servicios ambientales para los robldales de la Cordillera de Talamanca

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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

Two new endemic species of scarab beetles are described from Costa Rica, Onthophagus humboldtisp. nov. and Uroxys bonplandisp. nov.Onthophagus humboldtisp. nov. is also the tenth brachypterous Onthophagus species to be described worldwide, representing also a case of extreme brachyptery in Onthophagini. Illustrations for both new species, as well as marking differences with closely related species are included. Maps showing the distribution of the new species, as well as the distribution of brachypterous and endemic scarab-beetle species for Costa Rica are presented and discussed. The Cordillera de Talamanca represents an area where Scarabaeinae (four genera) show very high known levels of brachypterism in Mesoamerica. A reconstruction of the montane environment in the Cordillera de Talamanca during the Last Glacial Maximum (~24 ka) is analyzed, in order to try to understand a possible historical biogeography model that might promote high levels of brachypterism in scarab-beetles. The present study supports previous proposals that brachyptery is correlated with stable environments associated with deeply incised valleys. Tropical mountain ranges are also identified as having more endemics than lowland rain forests, contradicting accepted wisdom. Lastly, a mitochondrial DNA analysis supports the existence of the Onthophagus dicranius and the O. clypeatus species-groups as two well-defined and closely related branches.

A new species of dink frog, genus Diasporus (Anura: Eleutherodactylidae), from the Caribbean foothills of the Cordillera de Talamanca, Costa Rica

A new dink frog (Eleutherodactylidae: Diasporus) is described from the Tropical Wet Forest, in the northeastern foothills of Cordillera de Talamanca in Costa Rica at an elevation of ca. 1000 m. Analysis of DNA sequences of the 16S rRNA (16S) and cytochrome oxidase 1 (COI) mitochondrial genes revealed a distinct lineage within the genus Diasporus. Additional morphological, morphometric, and acoustic analyses support the differences of this lineage, which we recognize as a new species. This new taxon is distinguished from other members of the genus Diasporus inhabiting Isthmian Central America by its unique coloration: dorsum brown to brown-grayish and venter gray-bluish with pale blotches. The new species is distinguished from other members of the genus Diasporus by very significant genetic distances (higher than 5.6 % in 16S and 16.7 % in COI). The new taxon is most closely related to D. vocator from the south pacific of Costa Rica and to an unnamed taxon from western Panama.

Cosmogenic Cl-36 surface exposure dating of late Quaternary glacial events in the Cordillera de Talamanca, Costa Rica

Geomorphic evidence of past glaciation, such as U-shaped valleys, aretes, glacial lakes, and moraines, is preserved in the highland surrounding Cerro Chirripó in the Cordillera de Talamanca, Costa Rica. Previous work to establish a glacial chronology has focused on relative age dating of moraines and on radiocarbon dating of basal lake sediments to infer the timing of deglaciation. We used cosmogenic 36Cl surface exposure dating to constrain the ages of moraines within two formerly glaciated valleys, the Morrenas and Talari valleys. Forty-nine boulder samples were processed and measured from four moraine complexes in the Morrenas Valley and two moraine complexes in the Talari Valley. The exposure ages of these samples indicate a major glacial event occurred in this area from ~25 to 23 ka, broadly synchronous with the global last glacial maximum. Our results also indicate periods of glacial retreats and standstills from the deglacial period to the Early Holocene (~16–10 ka) before the complete disappearance of glaciers in this highland. These findings provide important insights into the glacial chronology and paleoclimate of tropical America.

A new species of Craugastor (Anura: Craugastoridae) from the montane rainforest of the Cordillera de Talamanca, Costa Rica

A new species of Craugastor (Anura: Craugastoridae) from the montane rainforest of the Cordillera de Talamanca, Costa Rica. A new dirt frog of the Craugastor podiciferus Species Group is described from Costa Rica; it is restricted to elevations between 2330 and 2700 m a.s.l. in the montane rainforest of the Cordillera de Talamanca. Analysis of DNA sequences of the mitochondrial 16S rRNA (16S) and cytochrome oxidase I (COI) genes reveals a distinct lineage within the C. podiciferus Species Group. Additional morphological and morphometric analyses support the distinctiveness of this lineage that is described as a new species herein. The species is distinguished from other members of the C. podiciferus Species Group by its unique coloration: a violet-brown to blackish brown venter with white pigment forming blotches, and dark brown palmar surfaces with prominent white folds between subarticular tubercles in the adults. The genetic divergence of the species from other members of the C. podiciferus Species Group is signifcant (higher than 9.2% in 16S and 13.3% in COI). Although not closely related, it resembles C. podiciferus morphologically, a species that also inhabits montane rainforest. The discovery of this new species highlights the importance of montane rainforest as a center of species richness and endemism.