José Daniel Ramírez Fernández

University of Costa Rica | UCR · Escuela de Biología

We conducted a questionnaire using the Participatory Research approach on Google Forms to collect information and data on the jaguarundi Herpailurus yagouaroundi for the IUCN Red List Assessment RLA. We collected information on ecological and conservation aspects from 69 participants from 18 countries, covering most of the species’ range and gather...

Mammal diversity in Costa Rica is considerably high given the size of the country (51,100 km2), and has increased in recent years. Taxonomic changes together with distribution extension records have contributed to such an increase. Here we present the revised and updated list of mammals confirmed for Costa Rica based on previous lists and recent ad...

The Costa Rican highlands are considered hotspots of diversity and endemism, but studies on rodents are scarce. We compared the richness and abundance of mice between the montane forest and the paramo at the summit of the Talamanca mountain range. We selected two study sites within the Talamanca mountain range: the Cerro de la Muerte Biological Sta...

In May 2022, the First Small Wild Cat Working Groups Meeting of the Neotropics was held in Piura, Peru. In this meeting, seven Working Group WG leaders presented their threat mitigation activities on behalf of the conservation of 10 species of small wild cats distributed in Latin America. Because threats are similar for all small cats co- occurring...

Ichthyomyini, a morphologically distinctive group of Neotropical cricetid rodents, lacks an integrative study of its systematics and biogeography. Since this tribe is a crucial element of the Sigmodontinae, the most speciose subfamily of the Cricetidae, we conducted a study that includes most of its recognized diversity (five genera and 19 species...

Small wild cats have gone unnoticed by the conservation world for many years. Under the umbrella species concept, most cat conservation programmes around the world have focused on the seven largest generalist species, leaving more than 30 species of small specialists to fend for themselves. The Central American oncilla Leopardus tigrinus oncilla, t...

The advance of urbanization in Neotropical countries has drastically changed or eliminated extensive areas of natural habitats. Despite these changes, some species breed in cities and adapt to urban conditions. Several variables, such as the type of nest, substrate, and height, as well as the distance to buildings at which nests are constructed, ma...

The Tiger Cats species complex is comprised of four distinct taxonomic entities, with two currently recognized species, Leopardus tigrinus (including the subspecies tigrinus, pardinoides, oncilla) and Leopardus guttulus, that potentially could comprise 3-4 entirely different species. Leopardus tigrinus, L. pardinoides, L. oncilla, and L. guttulus....

Tweedy’s Crab-eating Rat, Ichthyomys tweedii Anthony, 1921, was described based on just a few specimens, and many aspects of its biology remains unclear. The species has only been previously reported to occur in two geographically disjunct areas in Panama and Ecuador. We report a new record of this species for southern Costa Rica. Our new record is...

Conservation efforts in terrestrial environments have focused on preserving patches of natural habitats and restoring disturbed habitats, with the main goal of transforming them into forests or habitats that resemble the original conditions. This approach tends to overlook the importance of conserving early succes-sional vegetation (e.g., riverside...

Neotropical wild rodents from Costa Rica were analyzed for the presence of herpesviruses (order Herpesvirales, family Herpesviridae). Using a broadly generic PCR, herpesvirus sequences were detected in 5% (8/160) of liver and heart samples: seven putative gammaherpesviruses in samples from Talamancan oryzomys (Nephelomys devius), sprightly colilarg...

Feeding events of unsual prey items are rarely recorded in the field. Here we report diet resources for eleven Neotropical bird species. We include an observation of scavenging behavior for the Black Hawk-Eagle (Spizaetus tyrannus), the first record of wood consumption by the Crimson-fronted Parakeet (Psittacara finschi), moss consumption by the Me...

Costa Rican highlands are unique and threatened ecosystems in the world, mostly inhabited by endemic species. The Talamancan Deer Mouse is a specialized feeder in oaks and an important disperser, suggesting a highly dependent mice-oaks relationship. To know the population status and habitat preferences of mice will likely reveal the conservation st...

Deforestation and changes in land use have reduced the tropical dry forest to isolated forest patches in northwestern Costa Rica. We examined the effect of patch area and length of the dry season on nestedness of the entire avian community, forest fragment assemblages, and species occupancy across fragments for the entire native avifauna, and for a...

Deforestation and land use change have reduced the tropical dry forest in the northwestern region of Costa Rica into isolated fragments. We examined the effect of fragment area and length of the dry season (seasonality) on nestedness for the community (entire species matrix), assemblages (forest fragments), and species occupancy across fragments fo...

Deforestation and land use change have reduced the tropical dry forest in the northwestern region of Costa Rica into isolated fragments. We examined the effect of fragment area and length of the dry season (seasonality) on nestedness for the community (entire species matrix), assemblages (forest fragments), and species occupancy across fragments fo...

The Rufous Tree Rat, Diplomys labilis, is known to range geographically from Central Panamá to Colombia and probably Ecuador. It occurs in a variety of habitat types where it moves by the branches in the high canopy at night. We report the Rufous Tree Rat for Costa Rica, ranging outside its geographical distribution about 490 km west from its type...

Predation of Rhinophrynus dorsalis by Pulsatrix perspicillata in Santa Rosa National Park, Guanacaste, Costa Rica.

Range extension of S. anthracops in Nicoya Gulf, Costa Rica.

Although Costa Rica is a small country, it has a high diversity of mammals. The study of mammalogy in the country dates back to the early nineteenth century with the presence of the first European and Costa Rican naturalists as Alfaro and Zeledon. Despite extensive studies in Costa Rica there are still many species of mammals to be recorded. Proof...