Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Molecular studies of Neotropical Myotis (Chiroptera, Vespertilionidae) in the last decade have uncovered substantial cryptic diversity.  One example is M. keaysi pilosatibialis, which is characterized by a complex taxonomy derived from low morphological variation.  Herein, we studied cryptic diversity of a high elevation clade from premontane and montane forest of Chiriquí Province (Panamá), Cordillera Oriental (Ecuador), and Valle del Silencio (Costa Rica).  Additionally, we disentangle relationships of M. k. keaysi and M. k. pilosatibialis by determining their phylogenetic placement within the Neotropical Myotis radiation.  In the process, we identified a new lineage of species level hierarchy that is described herein.  We used an integrative taxonomy approach, using a combination of linear morphometrics, qualitative morphology, molecular phylogenetics, and climatic analysis.  The newly identified lineage is a sister species to M. pilosatibialis str., but differs from M. sp. (Quintana Roo, México), M. keaysi str., and M. oxyotus gardneri in size and other quantitative morphological characters in addition to both nuclear and mitochondrial DNA sequence divergence.  Based on our phylogenetic analysis of partial cytochrome b sequence, the polyphyly of M. keaysi str. and M. pilosatibialis str. is resolved, with M. keaysi str. paraphyletic to M. ruber and M. simus.  Myotis pilosatibialis is part of a monophyletic clade that is sister to the newly identified species.  This report refines our understanding of taxonomy and systematics of the Myotis pilosatibialis complex of bats, identifies and describes a new species of Myotis, and more broadly it contributes to efforts to characterize species in this genus in Neotropical environments.  Based on its distribution, we classified this newly described species as paramontane due to its restriction to premontane and montane forest of Chiriquí Province (Panamá), Valle del Silencio (Costa Rica), and Cordillera Oriental (Ecuador).  These habitats are susceptible to the effects of climate change, in addition to ongoing habitat destruction.  

The broad-nosed bat, Platyrrhinus ismaeli, is listed as Near Threatened (NT) by the International Union for the Conservation of Nature, and due to the low number of collected specimens, its geographic distribution is poorly known. This study presents the first documented record of this species in the eastern slope of the Colombian Central range. Herein, museum voucher specimens were used as primary sources for the elaboration of a checklist of Platyrrhinus ismaeli from Colombia. In addition, the checklist is supplemented with information on life zones and a potential distribution model for Colombia. This distribution map was used to explore the affinities, in species composition, among Colombian ecoregions as outlined by, and the relationship between associated environmental variables. In total, 15 field-based occurrence points and 20 environmental variables (19 bioclimatic and one topographic) were used to model the potential distribution area. The response curves showed that this species prefers habitats with an annual temperature of 12.0 to 25.5 °C, annual precipitation of 1,000 to 4,000 mm, and an elevation range of 1,200 to 2,850 masl. Most of the current potential suitable conditions were located to the north-center of Colombia. We found that P. ismaeli is distributed in Colombia in four main regions, including the Biogeographic Chocó, the Magdalena Valley, the Orinoquia, and the Guianan-Amazon region. The spatial distribution of the species is driven by variables such as temperature, precipitation, and elevation. Changes in these variables affect the normal activities of this species with a narrow geographical niche and dispersal ability may particularly reduce the ability of this species to face global climate change consequences. Therefore, it is imperative to continue exploring the effect of these variables in order to better define the distribution patterns and conservation strategies for this species. Our findings can be used to define high-priority areas for the protection and conservation of P. ismaeli.

The Gran Sabana is a region of great biogeographical and conservation value that has been recently threatened due to increasing overexploitation of natural resources and illegal mining.  Systematic survey methods are required in order to study species responses to landscape transformation.  The main objectives of this study were: 1) to test the relationship between habitat types and mammal species presence in the Gran Sabana and Canaima National Park (NP), and 2) establish baseline methodology that can set guidelines for future, considering sampling limitations, conservation opportunities and increasing threats to biodiversity in this region.  We implemented a stratified sampling design using camera traps for monitoring medium and large mammals in two previously under-sampled regions in the Gran Sabana, south-east Venezuela.  We analysed time-series of remotely sensed vegetation indices to classify habitat types and summarized relative abundance of mammals, naïve occupancy, and habitat fidelity for each type.  With a sampling effort of 5,523 camera*days, 29 species of mammals were recorded, including endangered Priodontes maximus, and vulnerable: Speothos venaticus, Tapirus terrestris, and Panthera onca. Cuniculus paca and Dasyprocta leporina were the most frequently registered, while Hydrochoeris hydrochaeris, Leopardus wiedii, and Leopardus tigrinus had few records.  Most of the species were associated with forest (13), fewer with transitional shrub (7) and savanna (5) habitats, but only some of these were statistically significant.  Cerdocyon thous show significant association with savanna (P < 0.01), whereas Leopardus pardalis (P < 0.05) and Cuniculus paca (P < 0.05) with shrub-intermediate habitat.  As many as seven species: Dasypus kappleri, Dasyprocta leporine, Mazama americana, M. gouazoubira, Nasua nasua, Priodontes maximus, and Tapirus terrestris have statistically significant association to forest habitat (P < 0.05).  We present the first record Myoprocta pratti for Canaima NP.  We found higher species richness of large- and medium-sized mammals comparable to lowland Guianas and Amazon sites.  Four species remained undetected, probably due to low abundance or detectability, but Sylvilagus brasiliensis seems to be truly absent from the Gran Sabana.  Uncontrolled development of Orinoco Mining Arc on the border of Canaima NP and the Gran Sabana raised new ecological and social concerns.

The South American river dolphins of genus Inia are distributed throughout the Amazon, Orinoco and Araguaia-Tocantins basins.  They are categorized as Endangered and the knowledge on their basic ecology is still scarce.  Therefore, investigation efforts must contribute to the knowledge and conservation of these species in their area of distribution.  For the Bolivian river dolphin we used a database of 10 years of upstream and downstream surveys, accumulating approximately 6,100 km of double routes from three main rivers of the Upper Madeira River basin (Ibare, Mamoré and Tijamuchi) by following standardized methods where each encounter with a single or a group of river dolphins was registered.  Preferred sites by Bolivian river dolphin were based on Kernel density estimation.  This methodology considers the accumulated data of georeferenced sightings, generating a map of probability of occurrence in each river.  In the three rivers, the accumulated density of sightings is concentrated in meanders and confluences, resulting in a high probability of sighting Bolivian river dolphin in these habitats.  It was also identified that the number of Bolivian river dolphin sightings decreased over time in the upper Tijamuchi River.  The Bolivian river dolphin preferred both meanders and confluence habitats.  Between the Ibare and Tijamuchi rivers (Mamoré sub- basin), the distribution of the species tended to be more uniform.  According to these results, it is important to reinforce the management of the Ibare-Mamoré municipal protected area, since important Bolivian river dolphin populations are concentrated there.  Same trend was also shown in the lower-middle zone of the Tijamuchi River, suggesting the need of implementing conservation strategies in this area, where currently there are none.

Scavenging of carrion is essential to terrestrial ecosystems and can shape food webs and behavior.  The prevalence and importance of scavenging has often been underestimated and overlooked in food web studies.  Small-mammal carrion is even less studied and difficult to estimate, especially in the Neotropics.  This project explored small-mammal carcass scavenging in a Neotropical, mid-elevation rainforest, and specifically studied the rate of carcass removal by scavengers, how the conspicuousness and weight of carcasses affect scavenging, and what vertebrate scavengers utilize this carrion resource.  I deployed 194 mouse carcasses of various weights, above and below the leaf litter, and surveyed them daily until disappearance.  I paired each carcass with a trail camera to help identify vertebrate scavengers.   A general linear model analysis showed that most mouse carcasses disappeared within 1 to 2 days.  Carcasses above the leaf litter were removed quicker and larger mice generally lasted longer.  Only 6.25 % of the carcasses were removed by vertebrates.  Most carcasses were removed by something too small to trigger the trail cameras, likely scarab beetles.  The results of this study show that small-mammal carcasses are a sought-after resource in Neotropical forests, and that invertebrates are able to quickly hoard and secure small carrion more efficiently than vertebrate scavengers.  A better understanding of scavenging ecology in Neotropical forests will help in developing a broader framework of the trophic interactions within and across ecosystems.

We present an updated checklist of ectoparasite species (including mites, ticks, lice, and fleas) infesting cricetid and heteromyid rodents (Rodentia: Cricetidae and Heteromyidae) in Mexico. For each parasite species, we include information on parasite taxonomy, host associations, collection localities, citations from the literature, and museum collections, when available. We recorded more than 172 mite, 114 flea, 22 tick, and 22 louse species from a minimum of 110 host species (82 cricetid and 28 heteromyid species) distributed across 31 states in Mexico. This work represents the most up-to-date and comprehensive checklist of ectoparasite species parasitizing cricetid and heteromyid rodents in Mexico.

Alto Beni region in Bolivia, presents a mosaic of non-extensive family crops ranging from monocultures to agroforestry systems immersed in a matrix of secondary forest, while the primary forest remains on the steeper slopes. Very little is known about the biology of the rodent species that inhabit this area. Then, the objective of this work was to determine the diet and its variation among three species of sigmodontine rodents (Akodon dayi, Euryoryomys nitidus and Oligoryzomys microtis) from 11 agroforestry systems (SAF) of cacao (four traditional monoculture / simple SAF plots, three intermediate SAF and four complex SAF) and two secondary forests. We analyzed contents of the stomach, cecum and intestine for 41 O. microtis (simple-SAF n = 31, complex-SAF n = 4 and forest n = 6), for 11 E. nitidus (simple-SAF n = 6, intermediate-SAF n = 2, complex-SAF n =3 and forest n = 2) and for 10 A. dayi (simple-SAF n =5 and forest n =5).  We calculated trophic niche width (Levin’s Index) and measured the degree of niche overlap (an estimate of competition), using Pianka’s Symmetric Overlaying Index. Significant differences in the diet specialization among species across habitats, were tested using the non-parametric Kruskal-Wallis test.  A total of 55 food items were obtained and grouped into nine food categories: dicotyledonous vegetative structures, monocotyledonous vegetative structures, vascular tissue, spikelet, seeds, mycorrhizae, adult arthropods, larval arthropods, and others. The study species feed primarily on plants of the family Poaceae. No significant differences were found in the diet between species or between SAF and the forest (P > 0.05); in addition, there was no evidence of a noticeable overlay of trophic niches by habit type. In the studied season, we found that: O. microtis and E. nitidus are herbivorous omnivore; “generalist” simple-monoculture-SAF and “less generalist” in complex-SAF; besides, O. microtis is “generalist” in forest and E. nitidus is “specialist” in complex-SAF and in forest; while, A. dayi is herbivore-insectivore; “generalist” in simple-monoculture-SAF and in forest.  Our results indicate that there is a strong relationship between, the type of plot where they were found and food availability in each habitat.

Bats play vital roles in nature as pollinators, seed dispersers, and natural controllers of insect pests. They serve as indicators of habitat disturbance and provide an insight into the health status of an ecosystem. This enormous importance contrasts with the lack of information on the current state of their roosts in Bolivia, particularly as regards caves and caverns. A search for caves and caverns was carried out in the eastern department of Santa Cruz, Bolivia, corresponding to the Brazilian-Paranense biogeographic region. Subsequently, an environmental-structural characterization of the caves was conducted to obtain biological information by capturing and identifying bats in eastern Bolivia. Interspecific associations in caves and the relationship between roost characteristics and bat diversity were explored and described based on the variables evaluated. A total of 19 caves were evaluated. A correlation between environmental and structural parameters was investigated, showing a relationship between cave length and humidity. Seven species of cave bats were identified, and two species of threatened Bolivian bats (Lonchorhina aurita and Natalus macrourus) were found in four caves. The caves evaluated are new records of this vital habitat for bats in the country. The presence or absence of bat species was found to depend on the structural characteristics of the cave (length, complexity), but not on temperature, although humidity may play a role in the presence of species. Among the species found, those highly specialized in the selection and use of roosts at caves could be prone to local extinctions. It is suggested that further investigations should be carried out on the ecology of these cave-dwelling bat species to identify the roosting patterns of bats and their distribution range, to elaborate conservation and management programs for caves and the animal communities sheltered.

Sydney Anderson and the "Mammalian Diversity in Bolivia" (MDB) project (1984-1993) established a highly productive model for integrated specimen-based field expeditions.  We assess the extended impact of that decade-long series of holistic surveys of mammalian diversity as a productive model for building enduring and highly integrated infrastructure for biodiversity research.  We point to specific examples of impact, but more generally make a case for Sydney Anderson’s prescient view that collections, over time, become ever more powerful and essential scientific tools for understanding mammalian diversity and our rapidly changing planet.  To assess the number of specimens held in collections and their availability for spatial analyses, we queried the Global Biodiversity Information Facility (GBIF) for Bolivian specimens. Results were downloaded and non-georeferenced specimens were georeferenced in GeoLocate. Publications utilizing specimens or data from the MDB project were identified in Google Scholar, these were used to build a citation profile to analyze impact and breadth of research.  Over the course of the decade-long MDB project ca. 10,000 new “holistic” specimens were added to natural history collections in Bolivia and the United States.  These specimens and data were used in over 500 papers across a broad range of research areas, including new records for the country, and many descriptions of mammals (nine) and parasites (34) new to science.  The Google Scholar profile generated for these publications has more than 20,000 citations and a citation H-index = 68 and an i-10 = 340.  Sydney Anderson’s legacy will endure through the exceptional collections he helped to build and the wide array of students he helped to inspire.  As societal concerns related to environmental change (e. g., biological annihilation, climate change, emerging zoonotic pathogens) become more pressing, scientific questions evolve, and technology continues to develop, these critical resources will be called upon more and more frequently. Thus we can confidently predict that the value and use of the Bolivian mammal specimens  archived under Syd Anderson’s leadership will continue to increase in the future.

Biological collections have become a key tool for biodiversity research. They are repositories of germplasm and data on modified or extinct natural populations, providing valuable information for understanding anthropogenic impacts on the natural world. We appraised the scientific value of the three mammal collections maintained by the Instituto Politécnico Nacional of Mexico (IPN): Escuela Nacional de Ciencias Biológicas (ENCB), CIIDIR Durango (CRD), and CIIDIR Oaxaca (OAXMA). We evaluated their specimen inventory, geographic coverage, and scientific importance for mammalogy. We assessed their physical conditions and provided insights into their future as data sources for understanding natural changes in the 21st century. We measured the scientific importance of the collections in terms of the number of specimens and taxa held and their geographic coverage. We also quantified research projects, publications, theses, and dissertations that have used at least one specimen, associated data, or materials deposited in these collections. We assessed their physical conditions by comparison with the standards set by the American Society of Mammalogists. As of 2018, these collections held a total of 61,560 cataloged specimens (ENCB 44,275; CRD 12,163; OAXMA 5,122), the largest repository of Mexican mammals in the Americas. All the orders, 86 % of the genera, and 69% (342) of the species of terrestrial mammals known to inhabit Mexico are represented in these collections. Specimens from all the Mexican States are included, with CRD focusing mostly on the northern part of the country, ENCB on central and southeastern Mexico, and OAXMA on the southeast. Materials from these collections have been used for at least 285 peer-reviewed publications, 91 research projects, and 107 theses and dissertations. CRD keeps >9,000 tissue samples, while OAXMA keeps >300 tissue samples plus 1,139 echolocation recordings of 24 bat species. All collections meet most curatorial standards of specimen preservation and availability and are being actively used in research projects. Nonetheless, we believe a sound institutional policy is necessary for the IPN mammal collections to successfully face the 21st-century challenges, particularly for ensuring the availability of usable data for the scientific community, digitizing the holdings, and designing and implementing a long-term preservation strategy.