Revista de Biología Tropical

First pages

2025-05-01T22:49:15-06:00

Diversity of moths and butterflies of the southwestern region of Costa Rica

2025-03-26T09:54:16-06:00

Introduction: The Costa Rican southwestern region is considered one of the neotropical biodiversity hotspots. This geographically isolated forest embraces a rich diversity of moths and butterflies, which is still unknown for the most part.

Objectives: (a) Describe and compare the diversity of moths and butterflies among different localities of the southwestern Costa Rican region, and (b) identify information gaps in this group of insects.

Methods: Data for this study were collected in 12 different localities by parataxonomists and taxonomists for the national inventory of biodiversity led by INBio (National Biodiversity Institute) using different trap types, but relying mainly on light traps. We compared alpha and beta diversity of moths and butterflies among the six localities (Cortés, Piedras Blancas, Rancho Quemado, Agujas, Los Patos, Sirena) with more extensive sampling.

Results: The dataset consisted of 78 747 specimens, of which 2 096 were identified only to the order level. The remaining 76 650 specimens were classified to the family level (n = 48 families), genus, species, or morphospecies. Species and morphospecies were distributed across 37 families. The alpha and beta diversity varied across localities for the 12 families of moths and butterflies that were present in the six localities selected. In general, Piedras Blancas, Rancho Quemado, and Sirena stand out as the most diverse localities. The richness of species varied among different families. For most families Agujas, Los Patos, and Sirena contained more species, but some other families showed a different pattern.

Conclusion: Differences in the diversity of moths and butterflies over a northern-southern gradient likely correspond to species (individuals within species) adapted to different biotic (e.g., availability of host plants and food resources) and abiotic (e.g., microclimatic conditions associated to the complex topography of the region) conditions. Despite the large effort made by INBio in knowing and mapping the biodiversity of Costa Rica, and the economic and biological importance of the biodiversity, there are still a huge number of species to be known, named, and properly used.

Effect of elevation, habitat, and season in butterfly (Lepidoptera: Papilionoidea) assemblages in a tropical mountain

2025-03-26T10:15:25-06:00

Introduction: Spatial and temporal variation in the environment promotes biological diversity. However, the combined effects of elevation, seasonality, and habitat on butterfly diversity and abundance are still underexplored in rural tropical ecosystems. Butterflies, as bioindicators, offer an excellent opportunity to assess environmental impacts due to their sensitivity to changes in habitat.

Objective: This study aimed to evaluate the variation in butterfly abundance and species richness across different habitats, elevations, and seasons in a rural tropical mountain landscape in Costa Rica.

Methods: The study was conducted over six months, encompassing dry and rainy seasons. Butterflies were sampled along an elevational gradient (1200, 1500, and 1800 m) across two habitat types: grasslands and riparian forests. Sampling methods included hand nets and fruit baits in each transect and at each site over six months. We made six visits to each site, with seven transects sampled per visit to capture butterflies. We recorded a total of 1421 individuals representing 151 species.

Results: The Nymphalidae family exhibited the highest species richness and abundance. Butterfly abundance decreased with increasing elevation, but species richness patterns varied by family. Seasonal variation significantly affected both abundance and richness, with higher values recorded during the rainy season. Based on local abundance, rare species were more commonly found in riparian forests at higher elevations during the wet season. Habitat did not significantly influence overall butterfly abundance or richness.

Conclusions: Seasonality and elevation influence butterfly populations in tropical mountain ecosystems. The lack of a significant habitat effect suggests that other ecological variables may mediate habitat impacts. Further studies are required to clarify these dynamics, particularly the role of habitat heterogeneity.

Temporal changes in the diversity and abundance of stingless bee nests in an urbanized environment

2025-03-26T08:58:40-06:00

Introduction: Increasing urbanization has endangered many species to an unknown extent. Stingless bees (Apidae: Meliponini) are highly important pollinators of tropical plants. Some species are well adapted to urban areas and use man-made structures to build their nests. In Costa Rica, there are 59 stingless bee species, but no account of their urban richness and abundance has ever been made.

Objective: To describe the composition and dynamics of the social bee community on the campus of the University of Costa Rica in San José over a six-year period.

Methods: We systematically searched for stingless bee nests (active colonies) in trees, buildings, walls and other man-made infrastructure within a 31-hectare section of the campus in 2016 and 2022. We investigated species-specific nest heights and the host plant species chosen for nesting.

Results: In total, 89 nests were identified, consisting of five species of five genera (Lestrimellita, Partamona, Scaptotrigona, Tetragonisca, and Trigona). From 2016 to 2022, the stingless bee abundance increased by 23.5%, but the species composition remained the same. Tree cavities were the most attractive nesting locations, and their use increased within the sampling period. Overall nest survival was >64% for the study period.

Conclusion: All bee species utilized a variety of tree species, but strangler figs (Ficus spp., Moraceae) were the most important for nest construction. Nest height depended on the species and architecture. This work provides a framework for future studies on tropical social bee communities in urban areas and offers valuable information on their nesting biology in this habitat.

Diversity and abundance of insect visitors in four crops within a Costa Rican highland region

2025-04-08T09:45:04-06:00

Introduction: The interaction between plants and pollinators is vital for the reproduction of approximately 90% of angiosperms and directly affects ecosystems and agriculture. In tropical regions, 94% of plants require animal pollinators, and in Latin America, 58% of crops depend on pollination by insects. The stability and complexity of plant-pollinator interactions are influenced by several factors, such as floral morphology, which influences nectar accessibility and pollinator specialization.

Objective: To compare the diversity and abundance of insect floral visitors in avocado, apple, plum, and blackberry crops in San Gerardo de Dota, Costa Rica.

Methods: We systematically collected flower-visiting insects in these crops and identified them taxonomically to the lowest possible level. We then estimated alpha diversity for each crop and compared the community composition (beta diversity) of visiting insects among crops.

Results: In 12 sampling visits, we collected a total of 2806 insects from 75 families across all four crops. Alpha diversity was greater in the avocado crop for all three indices (⁰D, ¹D, and ²D). Apis mellifera was the most abundant species in all four crops, but Diptera was the most common group of visiting insects in avocado, particularly flies from the Syrphidae, Muscidae, Calliphoridae, Sarcophagidae, Sciaridae, and Tachinidae families. The insect community of the avocado crop was different from that of the apple, plum, and blackberry crops; however, the insect composition of the other crops was similar.

Conclusions: The avocado crop is generalist in terms of floral visitors; this may be attributed to the size of the flower corolla, as flies with short mouthparts usually choose to feed on flowers with small corollas. Flowers of the other crops have similar morphology and are mainly visited by bees. The native entomofauna are abundant on the crop flowers, likely playing an important role as pollinators.

Floral visitor diversity of ruderal plants in San Gerardo de Dota, Costa Rica: a highland agricultural-natural landscape

2025-04-07T13:29:40-06:00

Introduction: Wild plants rely mainly on insects for pollination, and many of these plants are essential to maintaining a diverse and abundant community of crop insect-pollinators. In Costa Rican highland ecosystems, the diversity and abundance of insect floral visitors have been poorly studied, despite their importance and proximity to crops in this area.

Objective: to determine the richness and composition of floral visitor insect species of native and ruderal herbaceous plants close to cultivated areas in San Gerardo de Dota, Costa Rica.

Methods: We systematically collected flower-visiting insects along transects in two different sites and identified them to the lowest taxonomic level. We estimated alpha diversity for each season and 11 plant groups created specifically for this study. We defined these plant groups based on flower morphology, life history traits, and their taxonomic relatedness. We also compared the insect community composition across seasons and plant groups.

Results: We collected a total of 1306 insects, mainly flies (Diptera), from 62 families on 46 plant species during 12 sampling visits. Insect diversity (alpha diversity) increased during the rainy season, possibly because resources (e.g., food and reproductive sites) for flies increase during this season. Insect species composition varied among plant groups. The most abundant insect communities overlapped extensively among plant groups, but other communities compose mainly by some tachinids, chloropids and wasps did not overlap between other plant groups.

Conclusion: Seasonal differences in flower-visiting insects could be attributed to a greater availability of resources during the rainy season. Differences in the composition of visitor insects across plant groups were likely influenced by temporal variation in blooming of the different plant groups, blooming intensity, and flower traits. To preserve the rich diversity of floral visitors and the pollination services they provide, a diverse array of ruderal plants must be maintained.

Yeast diversity in tropical fruits from Costa Rica

2025-04-08T11:28:30-06:00

Introduction: The yeasts consumed by the population in foods such as tropical fruits remain relatively unknown, despite being an important component of the human microbiota and having multiple biotechnological applications.

Methods: In this work we isolated and characterized the diversity of yeasts in fruits regularly ingested in Costa Rica, using culture-dependent methods, morphological characterization, and ITS marker sequencing.

Results: We isolated 118 yeasts from the 26 species of tropical fruits sampled, grouped into 7 families, 11 genera, and 19 species. Hanseniaspora pseudoguilliermondii, Pichia kluyveri and Hanseniaspora uvarum were the most abundant species. Notably, some species were present on several fruits, others presented a more specific host range, and some were only isolated after several months of fermentation.

Conclusion: Our work evidences the large diversity of yeasts present in tropical fruits, which motivates further study of their ecology, physiology, and potential biotechnological uses.

Keywords

Agricultural landscapes in Costa Rica: forest remnants account for a rich mammal (Mammalia) community

2025-04-08T16:59:02-06:00

Introduction: The effects of habitat loss and fragmentation on wildlife are complex processes mediated by factors other than habitat size and isolation alone. For example, the quality of the surrounding matrix, edge-induced effects, and proximity to large forest tracks are of particular importance. These factors may allow or limit animal movements and, thus, population persistence in human-modified landscapes. This is the case in some remaining forest fragments in Costa Rican landscapes.

Objective: To investigate the influence of the landscape composition on medium (< 10 kg) and large-sized (> 10 kg) terrestrial mammals thriving in an agricultural landscape, we surveyed mammal species in 30 sites in the Sarapiquí region, Costa Rica.

Methods: We used 45 camera traps to assess the richness and composition of mammal species in forest fragments embedded in pineapple plantations and pastures from 2013 to 2014. Richness estimates were calculated using capture-recapture models for closed populations. We adjusted the models for repeated count data analysis to determine landscape cover types that best explained species richness.

Results: Twenty-two species of mammals in nine orders and 16 families were recorded. Despite the habitat loss, fragmentation, and agricultural practice pressures over the years, the Sarapiquí region maintains a significant portion of its native mammalian fauna compared to comprehensive historical inventories available for the area. We found that forest cover best predicts the levels of species richness.

Conclusion: many forest-dependent species, such as the threatened Baird’s Tapir, can thrive in fragmented habitats in agricultural landscapes, while other species seem to be heavily affected by habitat modification and land use type. Forested areas and pastures with a high density of scattered trees and proximity to extensive forests could enhance the conservation of mammal communities despite the intense human land use in these agricultural landscapes.

Richness and abundance of non-flying terrestrial mammals in an urban environment in the Neotropic

2025-03-26T09:40:13-06:00

Introduction: Urban green spaces are becoming increasingly important refuges for native fauna. In Costa Rica, most of the human population is concentrated in the Central Valley, producing drastic changes in natural ecosystems as urbanization increases and consequently reducing the natural habitats of multiple species. Urban development generally decreases the native diversity of mammals.

Objective: We described the richness and abundance of medium-sized terrestrial mammals in fragments of second growth and secondary forest vegetation immersed in an urban matrix.

Methods: We conducted a landscape analysis to measure the green spaces and urban land cover, and surveyed terrestrial mammals using night baiting traps, diurnal counts in transects, camera traps, and occasional reports.

Results: We found six native and three introduced species of terrestrial mammals, representing less than 50% of the medium-sized mammal diversity reported for the Central Valley of Costa Rica 40 years ago. The common raccoon (Procyon lotor) and the variegated squirrel (Sciurus variegatoides) were the most abundant species, both capable of exploiting urban habitats. Introduced species, especially free-ranging and feral cats (Felis catus), were the most common species in the study site. Free-ranging introduced species may increase predation and disease transmission. Fragmentation, isolation, and lack of connectivity caused by urbanization are likely affect the populations of sloth species (Bradypus variegatus and Choloepus hoffmanni) in the study site.

Conclusion: Maintaining natural and seminatural spaces and native vegetation is essential to conserve urban biodiversity.

Habitat complexity influenced mixed-species bird flock composition and occurrence in highlands

2025-03-25T20:12:25-06:00

Introduction: Mixed-species bird flocks are groups that change rapidly throughout the day, influenced by factors such as resource availability, vocalizations, and habitat complexity. Habitat complexity can either enhance or limit interspecific interactions by increasing the number of species or individuals that interact. However, variations in habitat structure are often overlooked when studying mixed-species flock composition, leading to incomplete or unrealistic interpretations of factors influencing flock composition.

Objective: This study aims to investigate the relationship between the composition and occurrence of mixed-species bird flocks and the habitat complexity of a highland forest in Costa Rica.

Methods: We conducted this study along a 5.5 km transect in the highland area of Braulio Carrillo National Park in Heredia, Costa Rica (10°05' N & 84°04' W; 2100 m a.s.l.) from March to December 2019. Mixed-species flocks were surveyed twice weekly from 06:00 to 11:00 h. Habitat complexity was assessed using 16 plots (10x10 m) distributed across the study area to capture most of the habitat variation. We estimated the probability of occurrence at different habitat types for mixed-species flock that vary in sizes using kernel density estimation in QGIS.

Results: A total of 34 species were recorded across 125 mixed-species flocks, categorized into 50 small-sized, 46 medium-sized, and 30 large-sized flocks. Flock sizes were associated with different habitat characteristics. A positive association was found between higher canopy and understory cover, tree quantity, and diameter at breast height (DBH) with species composition and abundance in large-sized flocks, but not in medium- and small-sized flocks.

Conclusion: While the overall presence of mixed-species flocks was not limited by habitat structure, their size and composition were significantly associated with habitat.

Differences in foraging strategies and morphology of five warbler species (Parulidae) in a tropical mangrove forest

2025-03-26T13:49:55-06:00

Introduction: Understanding the factors underlying the interactions among closely related species continue to be an important issue in ecology and evolution. Warblers have been the group model for studying niche partitioning through interspecific competition, without considering other possible factors. A more recent approach includes species-specific morphologies as an important factor that correlates with habitat (or niche) partitioning.

Objective: to compare the foraging strategies of five warbler species (Setophaga p. erithachorides, S. petechia, Protonotaria citrea, Parkesia noveboracensis, and Leothlypis peregrina) in a mangrove forest, and to compare the foraging strategies of S. p. erithachorides, the only resident warbler, between periods (presence vs. absence of migrants).

Methods: We collected information on substrates and maneuvers used during foraging for the five warbler species during 39 sampling sessions. Each session consisted of recording information for 9 successive days every two weeks.

Results: P. noveboracensis differed extensively from the other species in the foraging substrates and maneuvers. The other species formed a more compact group, but some differences in both, substrates and maneuvers, were detected between S. p. erithachorides and L. peregrina. Differences in forging strategies correlate with differences in the morphology among the five warbles species. The foraging strategy of S. p. erithachorides differed between periods. This warbler used the substrates similarly in both periods, but used other maneuvers or change their frequency when migrants are present.

Conclusion: differences in the foraging strategy of five warblers can be attributed to a process of morphological and behavioral adaptation to an adaptive scape that includes differences in microhabitat, and biotic interactions (e.g., predation, prey availability) rather than exclusively to interspecific competition.

Flowering time and pollinator abundance determine the female reproductive success in the dioecious palm Chamaedorea pinnatifrons (Arecaceae)

2025-03-26T11:37:22-06:00

Introduction: Female fecundity in dioecious plants is influenced by ecological factors that affect pollen and pollinator availability. A high flowering synchrony between sexes, an abundance of pollen donors and pollinators are expected to increase female reproductive success.

Objective: To understand how fruit production is related to flowering phenology, sex ratio, abundance and proximity of reproductive males to focal pistillate plants, and pollinator abundance in the dioecious understory palm Chamaedorea pinnatifrons (Arecaceae).

Methods: We followed the population flowering of the study species in a montane forest in Costa Rica during 2012. We correlated the number of fruits and fruit set from 115 inflorescences (74 plants) with the size of male and female neighborhoods surrounding focal plants, as well as with plant size and floral display (number of flowers per inflorescence). We estimated pollinator abundance by sampling thrips (Thysanoptera) from staminate inflorescences throughout the plant reproductive season.

Results: Flowering was seasonal, with a high degree of overlap between the sexes. The sex ratio of reproductive plants did not significantly deviate from one (79 females and 88 males). Female reproductive success was not related to the abundance and proximity of pollen donors but was instead associated with plants possessing shorter stems, more leaves and flowers per inflorescence, and fewer female neighbors. Late-flowering inflorescences significantly produced more fruits and had a higher fruit set, which coincided with an increase in thrips abundance.

Conclusions: We hypothesized that a higher floral display acts as a signal effect to attract pollinators, while larger inflorescences with more flowers can attract more insects, resulting in greater pollination success. Moreover, late-flowering inflorescences seem to benefit from the increase in pollinator abundance at the end of the flowering season. Pollination of C. pinnatifrons and other Chamaedorea species is highly dependent on thrips; as a result, the reproductive success of these palms is susceptible to fluctuations in pollinator population sizes.

Climate seasonality and plant vigor effects on reproductive phenology of Potalia turbinata (Gentianaceae) in Costa Rica

2025-04-23T07:36:21-06:00

Introduction: Potalia turbinata (Gentianaceae) is a treelet distributed from Nicaragua to Panama. Information on its reproductive biology and phenology is lacking.

Objective: To describe the reproductive phenology of P. turbinata, morphologically characterize its fruits and seeds, and determine whether flower and fruit production correlates with climate (temperature and precipitation) and plant vigor.

Methods: The research took place at Tirimbina Biological Reserve in Costa Rica, January 2017–March 2019. Monthly counts of flowers and fruits were conducted on 86 plants. We used circular statistics to determine the duration and peak of flowering and fruiting. Fruit production was compared between years to describe reproductive cycles. We correlated flower and fruit abundance with climatic conditions. Plant measurements included height, basal stem diameter, leaf crop, seeds per fruit, fruit and seed dimensions, and fruit hardness. We used height, diameter, and number of leaves as proxies for plant vigor and compared plant vigor between fruiting (i.e., number of fruits) and non-fruiting plants.

Results: Flowering lasted 2–6 months per plant, peaking in April, while fruiting was prolonged (3–10 months), moderately peaking in August. Flower abundance was negatively correlated with precipitation, but fruiting showed no significant correlation with climate. Fruit production negatively correlated with plant height and positively correlated with basal stem diameter. Non-fruiting plants had more leaves than fruiting plants.

Conclusions: At the population level, P. turbinata flowered and fruited annually. Individuals were supra-annual, an uncommon reproductive pattern for tropical species. The correlation between flowering and lower precipitation supports possible insect pollination, though direct pollinator observations remain needed. The results concur with other studies indicating a correlation between fruit number and plant size. This investigation provides information on the reproductive phenology and fruit traits of P. turbinata, laying a foundation for future research into its interactions with pollinators and dispersers.

The role of nocturnal and diurnal pollinators in the commercial production of Dragon Fruit crops in Costa Rica

2025-04-07T13:47:55-06:00

Introduction: Dragon fruit (or pitahaya) cultivation is of growing interest in Central America. Several species of the genus Selenicereus (Cactaceae) are cultivated around the world, with S. costaricensis being the only species native to this region. The pollination syndrome of the species partially matches chiropterophily and phalaenophily, but floral visitors and their effect on commercial fruit production is not well known.

Objective: To analyze the reproductive system, the floral visitors and their effect on fruit size in plantations of S. costaricensis in Costa Rica.

Methods: We recorded the anthesis period, stigmatic receptivity, anther dehiscence and nectar production. We conducted pollination experiments (manual self- and cross-pollination) and evaluated the effect of nocturnal and diurnal natural pollination on fruit production and traits related to fruit size and weight. Flower visitors were filmed, identified, quantified, and their behavior was documented.

Results: Plants were self-compatible. All pollination treatments produced viable fruits, but there were differences in fruit weight and size. Natural pollination, nocturnal and diurnal combined, produced the biggest fruits, while self-pollination the smallest. The fruits generated by either nocturnal or diurnal pollinators were of good commercial size. Hawk moths and bees were the main pollinators; no visits by bats were detected. The flowers produced no measurable nectar volume. Mass visitation by bees in periods of 15–20 minutes at dawn was sufficient to produce large fruits.

Conclusions: Diurnal and nocturnal pollinators are equally effective producing highly profitable fruits. The management of Apis mellifera and native solitary bee species is recommended to increase production efficiency in these plantations. Manduca rustica hawk moths seem the natural pollinators of S. costaricensis, and bats played no role in the production of fruits.

Reproductive success, parental care, and nest morphology of Manacus candei (Passeriformes, Pipridae)

2025-03-25T20:44:30-06:00

Introduction: With the destruction of natural habitats due to human activities (i.e., agriculture and urbanization), species face new challenges to survive and reproduce. Some of the new challenges include predation rate and food resources, a lack of nesting substrates and the type of nesting materials (i.e., natural and artificial). Since predation is reported as the primary cause of nest loss in the tropics, studying its impact, along with nest morphology, in modified environments is essential to understanding its effects on species inhabiting these habitats.

Objective: This study evaluates nesting success and predation for the white-necked manakin (Manacus candei) in a fragmented area near the Tirimbina Biological Reserve (Costa Rica).

Methods: Between 2015 and 2019, 66 nests were monitored, 59 of which were used to calculate the daily survival rates (DSR) of the nests using the MARK program. The other seven nests were only monitored by camera traps to identify predators and observe the mother’s behavior. We measured 20 nests and compared the variation on morphology.

Results: The results suggest that DSR nests did not vary between months or years, and the constant survival model was the most suitable with an average of 95% and a real survival of 11.6%. This species suffered a 64% nest failure, mostly due to predation. In total, four nest predators were identified, three avian and a domestic cat. Additionally, two species of birds were observed stealing nesting material. Nests were very similar in morphology with a coefficient of variation below 38% in their measurements.

Conclusion: These results suggest that the non-natural garden zone could provide a safe nesting place for M. candei, since it could be acting on the predator community.

Acoustic and morphological differences in Colinus genus (Galliformes: Odontophoridae) support the occurrence of four species

2025-03-25T19:53:00-06:00

Introduction: The taxonomy of Galliformes species, a group closely associated with humans since antiquity, remains unclear at various taxonomic levels, producing taxonomic changes constantly.

Objective: Our objective is to provide morphological and acoustic data to support the recent taxonomic recognition of Colinus leucopogon (Spot-bellied Bobwhite) as a distinct species from Colinus cristatus (Crested Bobwhite).

Methods: Using a combination of morphological and acoustic analyses, we assessed the differences between these two recently recognized species and compared them with the two other well-established species within the genus: C. nigrogularis (Black-throated Bobwhite) and C. virginianus (Northern Bobwhite).

Results: Our acoustic analysis of male songs from 64 individuals showed significant differences in maximum amplitude frequency, song duration, and number of elements, which can act as a reproductive barrier between C. cristatus and C. leucopogon. Morphological analyses, however, revealed only limited differences, primarily in tarsus length and wing chord length.

Conclusions: Our findings suggest that while male song characteristics strongly support the recognition of C. cristatus and C. leucopogon as distinct species, morphological differences are less pronounced, potentially due to ecological factors such as habitat similarity and altitudinal distribution. This study highlights the importance of including both acoustic and morphological traits in resolving taxonomic uncertainties and understanding species boundaries in Galliformes.

Differences in duet coordination influence territorial response on a year-round territorial bird species

2025-03-26T07:32:36-06:00

Introduction: Twelve functions have been assigned to avian vocal duets (e.g., maintaining contact, mate guarding, signaling quality, or resource defense). To separate between functions of duets it is necessary to take into account who is the receiver, the information coded by the sender, and if there is a conflict between pair members. Duets used for resource defense (e.g., territory) are a more aggressive signal than solo songs because they act as a joint defense signal that encode a pairs’ strength or time together in the coordination of both individuals’ song. Therefore, interacting pairs may use duet coordination to respond according to rival information.

Objective: Our main objective in this study was to test whether the coordination in time and frequency of White-eared Ground-Sparrow (Melozone leucotis) pair duets influences the territorial response of conspecific pairs.

Methods: We recorded 2-5 duets from 31 territorial pairs and measured duet coordination by dividing each ground-sparrow duet into three sections (include sections here) according to each individual’s contribution. In each section we measured frequency range and duration and the difference in frequency range and duration between the introductory and middle section, and the middle and terminal section of each duet. We then used a playback experiments to test pair response to duet coordination. Each pair were exposed to two types of duets: highly coordinated duets and a poorly coordinated duets.

Results: We exposed 31 pairs to these two treatments during duet playbacks and measured their territorial response according to the simulated intruders’ duet coordination. We found that pairs that produced highly coordinated duets approached faster and spent more time closer to all playbacks. By comparison, territorial pairs spent more time closer to the poorly coordinated duet stimulus. Total number of vocalization produced in response to duet stimuli were similar between stimuli and independent of the duet coordination of the territorial pairs.

Conclusions: Our study indicates that, duet coordination in territorial pairs of White-eared Ground-sparrows is a good predictor of the strength in territorial defense and suggests that pairs used duet coordination to perceive the level of threat from an intruder.

Effect of the Limón earthquake (1991) on the biodiversity of marine macroalgae according to records from the USJ Herbarium for the Southern Caribbean of Costa Rica

2025-04-07T20:11:27-06:00

Introduction: On April 22, 1991, the third strongest recorded earthquake in the history of Costa Rica wreaked havoc on communities in the Limón province. Along with a great cost to human life and the economy of the region, the earthquake had another interesting effect: the uplift of the coastline. The ecological consequences of this event are considered some of the most impactful of the Limón earthquake, however, little is known about the true changes that occurred within communities of aquatic organisms, including marine macroalgae in the aftermath of this event.

Objective: To determine if there was an effect of the 1991 Limón earthquake on the composition of algal communities in the region extending from Limón to Manzanillo.

Methods: Data of algal specimens collected in three Caribbean localities (Limón, Cahuita, Manzanillo) between 1962-2021 was analyzed from the USJ Herbarium database. Intervals of five years were used to evaluate disturbances before and after the 1991 earthquake. Geographic-temporal differences were assessed using Bray-Curtis index based on the transformed data. The matrix was analyzed implementing a nMDS and a PERMANOVA. A SIMPER test was applied to determine the families with most variation followed by an ANOSIM to describe it.

Results: A total of 1086 algal specimens were analyzed. Among the sites, Punta Cahuita had the highest diversity and Punta Uva the lowest. The nMDS indicates that there is a difference in the composition of the algal communities in the locations consulted in the five year interval after the phenomenon compared to the other temporal periods. The Gracilariaceae family presented the most variation between sites.

Conclusions: The changes found in the composition of the algal community in the Caribbean region cannot be attributed only to the natural phenomenon described previously. There are several other environmental or anthropogenic components that should be considered, as they might influence the dynamics seen within the community, causing changes individually or in interaction with other factors.

Revalidation of Ptychophallus campylus Pretzmann, 1968, a freshwater crab species from Costa Rica (Brachyura: Decapoda: Pseudothelphusidae)

2025-03-26T10:33:09-06:00

Introduction: Freshwater crab diversity in the Neotropics is high, comprising three families: Epiloboceridae, Pseudothelphusidae and Trichodactylidae. The genus Ptychophallus consists of 13 species, all from Panama and Costa Rica. Ptychophallus campylus has not been recognized as a valid species and has been treated as a presumptive junior synomym of Ptychophallus tristani.

Objective: The present study aims to formalize the resurrection of P. campylus as a valid species.

Methods: An additional specimen of P. campylus collected in the province of Limón, Costa Rica, was analyzed and compared to both the holotype of P. campylus and the description of P. tristani.

Results: The gonopod 1 of P. campylus is morphologically similar to that of P. tristani but can be differentiated by the shape of the lateral process of the male first gonopod. Moreover, both species show different geographic distributions: whereas P. tristani occurs in hydrographic basins of the Pacific versant of Costa Rica, P. campylus seems to be restricted to the Caribbean slope in eastern Costa Rica.

Conclusions: Ptychophallus campylus is formally revalidated from the synonymy of P. tristani, confirming recently published results of multigene analysis that recovered both species in different lineages. This revalidation of P. campylus increases the number of valid species of the genus Ptychophallus to a total of 14, with nine species or 64.2% of all Ptychophallus species occurring in Costa Rica.

Annotated list of amphibians and reptiles of Costa Rica: The role of the Museum of Zoology in cataloging the country’s herpetological diversity

2025-03-26T11:02:21-06:00

Introduction: The herpetological collection of the Museum of Zoology at the University of Costa Rica (MZUCR) has been key to safeguarding a sample of the diversity of amphibians and reptiles of Costa Rica and to keeping the catalog of the species present in the country up to date. This unit develops phylogenetic and biogeographic studies on these animals and plays an important role in taxonomic decisions about them.

Objectives: In this work, we review and update the list of amphibians and reptiles of Costa Rica, commenting on cases with some taxonomic controversy. In addition, we briefly account for the MZUCR herpetological collection and explore its history.

Methods: We update the list of present species based on identifying specimens kept in our collection and reviewing relevant scientific literature. In addition, we compile the information available in internal documents and scientific publications to establish the history of the collection.

Results: We recognized 221 species of amphibians and 257 species of reptiles in Costa Rica, representing 17 and 36 families, respectively. More than 99% of amphibian species and 97% of reptiles are represented in our collection, which currently has more than 24,000 properly cataloged specimens. The collection houses 39 holotypes and 190 paratypes of 47 species, demonstrating its key role in taxonomic studies of the local herpetofauna. Although amphibian and reptile sampling cover almost the entire country, the northern lowlands and the Caribbean foothills of the Talamanca Mountain range require more significant collecting efforts.

Conclusions: Despite its long and intense history of biological exploration, records of Costa Rica's herpetological diversity continue to increase. Much of this growth is a result of efforts made at the MZUCR. Since its origin as a modest private collection in the early 1960s, it has grown into one of the most comprehensive collections of amphibians and reptiles inhabiting Costa Rica. It also functions as a research unit that generates substantial biological knowledge about both groups.

The ornithological collection at the University of Costa Rica: a perspective on historical and international collecting

2025-03-26T13:30:36-06:00

Introduction: Natural history collections play a vital role in research and education. However, their value and benefits are frequently overlooked, and the museum’s holdings tend to be unknown outside of museum personnel.

Objective: We aim to evaluate and report the taxonomic and geographic coverage of the ornithological collections of the museum of zoology at the Universidad de Costa Rica (MZUCR).

Methods: We estimated species-level and family-level representation across the six sub-collections of the collection of ornithology at MZUCR, and contrasted the taxonomic coverage and temporal patterns of the round-skin collection against other collections of Costa Rican birds housed in Costa Rica and abroad.

Results: The eggs and nests collection represent only a small fraction of the Costa Rican breeding birds (569 nests from 128 species and 117 egg clutches from 78 species). The skeleton collection is the smallest with little growth over time (353 skeletons from 203 species). Tongues collection is growing (845 tongues from 329 species) and expected to fuel future research in comparative morphology. The tissue collection is the most recent and has the highest growth rate (1979 samples from 408 species), reflecting the importance of molecular studies in current research. The round-skin collection has the highest representation of the Costa Rican avifauna (5080 skins from 761 species), but it represents a small fraction of all the specimens collected in Costa Rica.

Conclusion: These results highlight the importance of the MZUCR collection in documenting the Costa Rican avifauna, and its potential for ornithological research. However, the majority of species do not have the sufficient number of specimens required for robust population level studies. We underscore the importance of continuous growth and proper management of scientific collections for their use for future generations.

Listening the Costa Rican diversity: status of the bioacoustics collection of the Museum of Zoology, University of Costa Rica

2025-03-26T11:19:37-06:00

Introduction: Bioacoustic collections maintain, curate, and preserve animal sounds gathered by biologists and naturalists, serving as valuable archives of the planet's acoustic biodiversity. These collections facilitate the study of species behavior, distribution, and ecology. These collections provide valuable information for the conservation of endangered species and habitats.

Objective: This study describes the current status of the Bioacoustics Collection at the Museum of Zoology, CIBET, University of Costa Rica.

Methods: We reviewed the 4,366 recordings cataloged in the collection, and provided information on their distribution across taxonomic groups, and on the specific geographic locations within Costa Rica where they were obtained. We also discuss the importance of this collection as a key repository for bioacoustics research both nationally and internationally.

Results: The collection predominantly comprises bird recordings, representing approximately 58.15% of Costa Rica's avian species. Additionally, the collection includes recordings of other groups, such as amphibians and mammals.

Conclusions: The analysis revealed the importance of the collection for scientific research, conservation, and environmental education. This collection outstands as a vital resource for future bioacoustic research in Costa Rica and beyond. It also highlights the need to enhance the representation of other taxonomic groups and invites researchers to contribute to this repository, as a source for a better understanding the acoustic diversity and support conservation efforts.

State of knowledge of the Glomeromycota of Costa Rica

2025-04-08T19:47:40-06:00

Introduction: Arbuscular mycorrhizal fungi (AMF) play a pivotal role in plant nutrition and soil stability, also play an important role for sustainable agriculture and the restoration of degraded areas. In Costa Rica, research has been conducted on the diversity of AMF in select ecosystems. However, a comprehensive compilation of these studies is currently lacking.

Objective: To compile an updated list of arbuscular mycorrhizal fungi (AMF) in Costa Rica, organised by vegetation types and life zones. This will facilitate a more comprehensive understanding of their diversity and serve as a foundation for future research in taxonomy, distribution, ecology and biotechnological applications.

Methods: A comprehensive literature search was conducted in Google Scholar, Scopus and Web of Science, utilising Spanish and English terms related to arbuscular mycorrhizal fungi (AMF) and Costa Rica, spanning the period from 1971 to 2024. The selection criterion included studies that identified species based on morphological or molecular criteria. The following information was integrated into a database.

Results: We compiled 57 studies published from 1975-2024 and after screening 549 initial records, 115 records corresponding to species level were confirmed. 60 AMF species belonging to five orders were identified, representing 16 % of the global diversity known as Glomeromycota. The families Glomeraceae (23 species) and Acaulosporaceae (19 species) were the best represented. Furthermore, it was observed that studies have been conducted in only four of the 12 life zones described for Costa Rica, and include agroecosystems and trap crops (consortia) or pure crops (monospecific).

Conclusions: It is evident that there has been a degree of advancement in the comprehension of the ecology, diversity and distribution of AMF. Nevertheless, further ecological and taxonomic research is required, encompassing both morphological and molecular analyses, to facilitate the expansion of knowledge concerning the distribution and diversity of AMF in Costa Rica.