ABSTRACT Aim To conduct a biogeographical regionalization of El Salvador, based on the potential distribution patterns of the superfamily Scarabaeoidea and using Parsimony Analysis of Endemicity. Location El Salvador, Central America. Taxon Superfamily Scarabaeoidea (Insecta: Coleoptera). Methods Potential distribution models were developed for 160 species using Maxent. Based on the resulting potential richness patterns, a Parsimony Analysis of Endemicity was performed using hexagonal grids of 50 km 2 across El Salvador. Clades of cells sharing species compositions (geographical synapomorphies) were identified, and the regions corresponding to each clade were delineated. Results Five clades were identified, corresponding to the following biogeographic regions: (1) Pacific Lowlands; (2) Eastern Interior Valley; (3) Chortis Volcanic Front (Central American Volcanic Arc); (4) Western Interior Valley; (5) Northern Mountains. Main Conclusions Species distribution models, combined with parsimony analyses, strengthen the versatility of both methods for identifying biogeographical patterns at finer spatial scales, facilitate the first species‐based biogeographic regionalization of El Salvador, and demonstrate that micro‐scale analyses can reveal internal structure within broadly defined Central American provinces.

Central America is an understudied global hotspot of plant biodiversity and harbors Acrocomia aculeata (Coyol or Macaúba), a neotropical palm with significant potential for oil and biofuel production. Historically, the region has functioned as a biogeographic land bridge, an isthmus, connecting North and South American biota. Here, we investigate how genomic diversity and potential distribution patterns of A. aculeata are shaped across Central America. A total of 259 samples were collected from Guatemala, Honduras, Nicaragua, Costa Rica, and Panama, covering the full extent of the Central American isthmus. Using a double-digest genotyping-by-sequencing (ddGBS) approach and ecological niche modeling, we assessed variation at 1,523 single nucleotide polymorphisms (SNPs) and evaluated environmental suitability across the region. Our analyses reveal three major genomic clusters: Mesoamerican, Costa Rican, and Panamanian, each comprising subpopulations with distinct levels of genetic diversity. The Mesoamerican group (Guatemala, Honduras, and northern Nicaragua) exhibited the highest diversity and unique genetic signatures, likely reflecting historical migrations and acting as a biodiversity cradle during periods when southern portions of the isthmus were submerged. Biogeographic features such as the Nicaraguan Depression and the Talamanca Cordillera contributed to regional genetic differentiation. Ecological niche models identified Central American pacific lowlands, forested areas, rangelands, and agroecosystems as suitable habitats for A. aculeata. Our combined results reflect the evolutionary history and population structure of A. aculeata in Central America, highlighting the influence of South American source populations and regional barriers. These findings provide a critical foundation for conservation and breeding programs aiming to preserve the genetic diversity and adaptive potential of A. aculeata in a rapidly changing and neglected biodiversity hotspot.

terrestrial species that inhabits lowland and foothill rainforests and altered habitats (e.g., agricultural areas, pastures, and human settlements) from northern Mexico to the Pacific lowlands of Colombia and Ecuador at elevations of 0-1,500 m asl (Leenders 2016; Savage 2002).Few predators are known to target adults but raptors (e.g., Laughing Falcons, Herpetotheres cacchinans; Swallow-tailed Kites, Elanoides forficatus; and Crane Hawks, Geranospiza caerulescens) and snakes (e.g., Mussuranas, Clelia clelia, and possibly Central American Indigo Snakes, Drymarchon melanurus) might prey on

Abstract. Despite the increased interest in the hydrology of intermittent hydrological streams in recent years, little attention has been given to these systems in tropical forest environments. We present a unique set of hydrometric, stable isotopic, geochemical, and landscape mapping information to obtain a mechanistic understanding of streamflow generation in 20 nested catchments (< 1–159 km2) draining intermittent and perennial streams and rivers in the Chocó-Darien ecoregion, a tropical biodiversity hotspot, located in the Pacific lowlands of northern Ecuador that has been strongly degraded by deforestation and agricultural encroachment during the last half-century. Hydrological intermittency is mainly controlled by antecedent wetness due to the strong seasonality of precipitation. Nevertheless, the streambed of catchments draining intermittent streams remains humid throughout the year, even when surface water stops flowing, since evapotranspiration is reduced due to continued cloudy and foggy conditions during the dry season. Intermittent streams mainly located in conserved forested headwaters with shallow soils and a low permeability bedrock have a faster streamflow response to rainfall and shorter recession times than the perennial streams with high permeability bedrock in the catchment's degraded middle and lower parts. Isotopic information shows that rainfall during the wet period (January to May) contributes to streamflow generation in the intermittent streams, whereas rainfall during the wet season recharges the subsurface water storage of the perennial streams. Concentrations of major ions and electrical conductivity were lower in intermittent streams compared to perennial streams. We found a strong correlation between the catchments' geology and geochemical signals and a weak correlation with the topography, land cover, and soil type. These findings indicate that shallow subsurface flow paths through the organic horizon of the soil dominate streamflow generation in intermittent streams due to the limited water storage capacity of their bedrock with very low permeability. On the contrary, high bedrock permeability increases the water storage capacity and is replenished during the wet period, helping sustain streamflow generation throughout the year for the perennial streams. These findings suggest that geology may play an important role in driving hydrological intermittency, even in highly degraded tropical forest catchments, and provide key process-based information useful for water management and hydrological modelling of intermittent hydrological systems.

Loxocemus bicolor is the only representative of the snake family Loxocemidae, and is almost continuously distributed along the Pacific lowlands from western Mexico to Costa Rica, entering the semiarid Balsas Basin. Herein we provide the first record of the species for the Balsas Basin in Estado de México. Given this new record, we hypothesize that other species thoroughly distributed in the region may also be present in the state.

Acanthocephalans, which are in the family Polymorphidae, are a globally distributed group of endoparasites whose adults reside in the intestines of fish-eating birds, waterfowl and marine mammals. Adults of Polymorphus brevis and Pseudocorynosoma constrictum are endoparasites of fish-eating birds (Ardeids) and waterfowl (Anatidae), respectively, and are considered one of the most abundant and widely distributed species of polymorphids in freshwater systems from the Nearctic and Neotropical regions of Mexico and the USA. In the present study, sequences of cytochrome c oxidase subunit 1 (cox1) from mitochondrial DNA were generated from 67 specimens of P. brevis and 32 of Ps. constrictum from 12 localities on 6 biogeographic provinces in Mexico (the Trans-Mexican Volcanic Belt, Pacific Lowlands, Veracruzan, Californian, Sierra Madre Occidental, and Sonoran), plus the Temperate Prairies biogeographical province in the USA. The phylogeographic analyses indicated that the populations of both species lacked phylogeographic structure and exhibited high haplotype diversity, low nucleotide diversity and low Fst values among the biogeographic provinces; in combination with negative values in the neutrality test, these findings suggest that the populations of both species of acanthocephalan are undergoing expansion. The current evidence indicates that the biology of the definitive hosts, in combination with their migration patterns, could play a key role in shaping the distribution of haplotypes and the population genetic structure of the studied 2 acanthocephalan species.

Data sharing is not applicable to this article as no new data were created or analyzed in this study.

The Sierra Madre Occidental (SMO) is a biogeographic province of Mexico that serves as a corridor for the northward expansion of subtropical species, while also acting as a barrier for the movement of species between western and eastern Mexico. The SMO houses 57 species of amphibians and 160 species of reptiles, representing 19.4% of the total number of amphibian and reptile species found in Mexico. Ten amphibian and thirteen reptile species are endemic to the SMO, and >50% of amphibian and reptile species found in the SMO are endemic to Mexico. Five amphibian species and three reptile species are listed in a category of conservation concern in the IUCN Red List. Specific threats include habitat loss, logging, mining, pollution, and climate change. The SMO shares a significant percentage of its species with neighboring provinces. In the cluster analysis for amphibians, a group comprising the SMO, the Pacific Lowlands, and the Chihuahuan Desert is linked to the Transvolcanic Belt. For reptiles, two distinct groups emerge: one including the SMO and the Chihuahuan Desert and one including the Transvolcanic Belt and the Pacific Lowlands. In conclusion, the rich biodiversity of the SMO, along with its role as both a corridor and barrier for species distribution, highlights the importance of targeted conservation efforts to mitigate the various threats facing this biogeographically significant province.

Treefrogs in the family Hylidae make up almost 40% of the anurans in Mexico; however, beyond monographic work published >50 yr ago, we still know very little about their reproductive ecology. Herein, we investigated reproductive traits and compared life-history patterns among three hylid treefrogs distributed along Mexico's Pacific Lowlands, a biogeographically unique faunal region threatened by sea level rise. We examined museum specimens of the Mexican Leaf Frog (Agalychnis dacnicolor, n = 200), the Lowland Burrowing Frog (Smilisca fodiens, n = 340), and the Mexican Shovel-headed Treefrog (Triprion spatulatus, n = 336) collected during 1902–1965 from nine Mexican states. Adult males were smaller than females in all three species. Testes were largest in July and August, and gravid females were most common during July–August and largely absent by September. Juveniles were present from July to September. Gravid females exhibited positive relationships between body size and clutch size, with larger A. dacnicolor females also having larger eggs. Growth was difficult to discern because most samples were seasonally restricted, but unpublished collectors' notes revealed rapid growth to metamorphosis in T. spatulatus. Geographic variation in body size exhibited opposite patterns between A. dacnicolor and S. fodiens, whereas T. spatulatus had no clear relationship with geography. We provide the most comprehensive data on reproduction for these three treefrog species to date, including the first clutch size estimates for two of them addressing critical gaps in their life history and paving the way for a more complete understanding of life-history variation in Mexican hylids.

The Sierra Madre del Sur (SMS) is a biologically diverse biogeographic province found in south-central Mexico. It is therefore an area of interest from a conservation standpoint. Here we examine the diversity and conservation status of the amphibians and reptiles of the SMS and its subprovinces and determine their similarity with neighboring provinces. We compiled a list of the species of amphibians and reptiles occurring in the SMS and its neighboring provinces from the available literature and gathered information on their conservation status. We also compiled the herpetofauna of the three subprovinces of the SMS (Western, Central, and Eastern). The SMS houses 186 species of amphibians, of which 89% are endemic to Mexico and 53% endemic to the SMS. The SMS also contains 331 reptile species, of which 72% are endemic to Mexico and 23% are endemic to the SMS. The amphibian and reptile diversity of the SMS is concentrated in the Eastern subprovince. The significant number of amphibian and reptile species endemic to the SMS highlights its importance for conservation. Comparison with neighboring provinces shows that the SMS shares 33% of its species with the Transvolcanic Belt, 25% with the Pacific Lowlands and Balsas Basin, and 19% with Veracruzan. The SMS shares 52% of its reptile species with the Transvolcanic Belt, 42% with the Pacific Lowlands, 40% with the Balsas Basin, and 33% with the Veracruzan. The results of a cluster analyses suggest that the SMS does not represent a single unit in terms of its herpetofauna, since the three subprovinces do not cluster together. The Western and Central subprovinces cluster with the Balsas Basin and the Pacific Lowlands, whereas the Eastern subprovince clusters separately. We found that 25.7% of the evaluated amphibian and reptile species in the SMS are included in the International Union for Conservation of Nature’s (IUCN) Red List in some category of conservation concern (amphibians: 54.9%; reptiles: 6.8%). The Eastern subprovince hosts the highest proportion of species of conservation concern (93.8%). It is important to increase the number of areas protected by federal and state governments, especially in the Eastern subprovince, and to promote protections driven by local communities. These actions could help protect the herpetofauna of the SMS, especially the Eastern subprovince, which harbors a unique fauna and deserves special consideration from a conservation standpoint.

Juliet B. Wiersema. <i>The History of a Periphery: Spanish Colonial Cartography from Colombia’s Pacific Lowlands</i>.

The number of amphibian species described yearly shows no signs of slowing down, especially in tropical regions, implying that the biodiversity of amphibians remains woefully underestimated. A new species of poison frog is described from the Pacific lowlands of southwestern Colombia: Epipedobatescurrulao sp. nov., named for the Pacific music and dance genre known as "currulao" or "bambuco viejo". This species inhabits lowland forests from 0-260 m a.s.l. This taxon differs from congeners by having a combination of bright yellow blotches in the dorsal anterior region of the thigh and upper arm, homogenous dark-brown dorsal coloration, and advertisement calls of long duration and many pulses. We also describe the courtship call of E.currulao sp. nov., which is lower in frequency and shorter in duration than its advertisement call. Molecular phylogenetic analyses confirm the monophyly of the populations sampled and its position as the sister species of Epipedobatesnarinensis, which occurs in southwestern Colombia. Among species of Epipedobates, the new species has been previously confused with E.boulengeri, but the two species are allopatric and represent two divergent clades (1.77% divergent for 12S-16S and 5.39% for CYTB). These species can be distinguished by the presence of a bright yellow blotch on the dorsal anterior region of the thigh and on the upper arm of E.currulao sp. nov., blotches that are either more white than yellow or absent in E.boulengeri. In addition, the advertisement calls are distinct, with E.currulao sp. nov. having a single but long call in each call series while E.boulengeri has 2-6 calls in a series with each call being much shorter in length. Epipedobatescurrulao sp. nov. is the most northern species of Epipedobates, which extends southwards along the western edge of the Andes. Known as the Chocó, this biogeographic region has been largely converted to agriculture in Ecuador and is experiencing widespread transformation in Colombia, which may endanger E.currulao sp. nov. and biodiversity in the region. A Spanish translation of the main text is available in Suppl. material 8.

Review. Juliet B. Wiersema, The History of a Periphery: Spanish Colonial Cartography from Colombia’s Pacific Lowlands. University of Texas Press, 2023. 256 pp.

The Balsas Basin (BB) is a biogeographic province in south-central Mexico that straddles the Mexican Transition Zone and the Neotropical region. We provide a list of the amphibian and reptile species of the BB based on a detailed review and update of recent species lists of its constituent states. The BB is home to 51 native amphibian and 155 native reptile species, which represent 14.7% of the herpetofauna of Mexico. No amphibian and six reptile species are endemic to the BB. Six species of amphibians and seven of reptiles are categorized as being of conservation concern status (vulnerable, endangered, or critically endangered) on the International Union for Conservation of Nature’s (IUCN) Red List. The main threat these species face is habitat loss due to urbanization, agriculture, and pollution. The herpetofauna of the BB shows significant overlap with neighboring provinces. The composition of amphibian species in the BB is closest to that of the Pacific Lowlands, whereas the composition of reptile species is closest to the Sierra Madre del Sur and the Transvolcanic Belt. These findings suggest that while the BB supports significant amphibian and reptile diversity, its conservation importance may be limited due to the low levels of endemism and the relatively small proportion of species at risk.

The Pacific Lowlands (PL) of Mexico hosts a rich diversity of amphibians and reptiles, comprising 326 native species (76 amphibians and 250 reptiles) across 45 families. This region is significant from a biodiversity standpoint, accounting for 23.3% of Mexico’s total amphibian and reptile species, with 30 species being endemic to the PL. Notably, the PL ranks sixth in amphibian and reptile diversity among Mexico’s fourteen biogeographic provinces. The species composition indicates a complex biogeographic relationship for the province, which shares the highest percentages of species with the neighboring Transition Zone provinces, while also acting as a vital corridor for species adapted to varied environmental conditions. Despite its diversity, 24 species in the PL are of conservation concern, highlighting threats from habitat loss, urbanization, and the impacts of introduced species in the province. Our findings underscore the ecological significance of the PL and the urgent need for conservation efforts to protect its unique biodiversity.

Bourbon Cartography in New Granada - The History of a Periphery: Spanish Colonial Cartography from Colombia’s Pacific Lowlands. By Juliet B. Wiersema. Austin: University of Texas Press, 2023. Pp. xiv, 168. Abbreviations. Illustrations. Appendix. Notes. Glossary. Bibliography. Index. $60.00 cloth. - Volume 81 Issue 4

The History of a Periphery: The Spanish Colonial Cartography from Colombia's Pacific Lowlands by Juliet B. Wiersema (review)

Using the data provided in Ruiz-Carranza et al. (1996) the distributions of the 540 species of frogs and toads are partitioned among ten ecogeographic units of Colombia defined on the basis of precipitation and elevation. Sorne lowlands areas (Pacific lowlands, Amazonia) exhibit high diversity (85-94 species) but lowlands areas in general are impoverished (30-52 species), especially when contrasted with upland areas. The three Andean cordilleras harbor between 87 and 121 species of frogs and toads, demonstrating that the biodiversity of Colombia resides primarily in its montane components, not in its lowland rainforests. When biological endemicity is separated from political endemicity, five areas of high endemicity remain (the three Andean cordilleras, the Sierra Nevada de Santa Marta, and the Pacific lowlands). We endeavor to explain this description by recourse to cladistic analyses of several groups of leptodactylid frogs where we find that the general pattem of diversification is by meaos of horizontal diversification (allopatric speciation) with a minor contribution from vertical diversification.

Endemic species are biological singularities whose relevance lies in their unique history and the information they provide about the history of the area where they are distributed. This is the first compilation study that brings together all the available information on endemics of butterflies, a highly diverse insect group in Mexico. Based on the records of 272 endemic taxa deposited in biological collections, we generate distribution maps for each taxon, and describe the patterns of endemic distribution. We analyze the results based on biogeographical provinces, vegetation types, and altitudinal levels. We compared these distribution patterns with those of endemic taxa of vertebrates, plants, and other insect groups in Mexico. The greatest number of endemic butterflies is in the southwestern portion of the country, in the Sierra Madre del Sur and the Pacific Lowlands. In terms of ecological distribution, endemism is distributed mostly at low and middle elevations in Seasonally Dry Tropical Forests, Temperate Forests and Mountain Humid Forests, the latter being of special importance due to its reduced extent in the country. The similarity in species composition groups the provinces into three clusters that generally agree with the Nearctic and Neotropical regions, and the Mexican Transition Zone. In addition, we describe the sampling biases at the family and subfamily levels as well as the undersampled biogeographical provinces, considering the estimation of endemic richness and the heterogeneity of the area. With this information, taxa and priority areas are identified to allocate the sampling effort and thus increase knowledge about the endemic taxa of the country. Nymphalidae were the family with the most records and endemic taxa, while Lycaenidae were the least endemic family in the country. We propose the Sierra Madre Occidental as the highest priority for directing the sampling effort for endemic butterflies. Finally, we discuss the historical and ecological causes of the distribution of endemic butterflies and compare it to the distribution patterns of endemic vertebrates and plants. Insects represent most biodiversity worldwide and are relatively poorly known compared to vertebrates or vascular plants. However, insects are just as threatened by ecosystem modification as other taxa. This work contributes to the urgent need to record biodiversity and thus prioritize conservation and resource management schemes.

Abstract The individual tracks of 47 bird species endemic to the Pacific Lowlands biogeographical province, which belongs to the Mesoamerican dominion of the Neotropical region, were used to revise its biogeographical regionalization. As a result, the six biogeographical districts previously recognized are classified in two subprovinces: the Coastal Lowlands of Nayarit-Sinaloa subprovince, stat. nov., which includes the Sinaloan, Tres Marías Islands, Revillagigedo Islands, and Guerreran districts; and the Coastal Lowlands of Southwestern Mexico subprovince, stat. nov., which includes the Tehuanan and Tapachultecan districts. Bird species supporting the biogeographical subprovinces and districts recognized are listed. The recognition of the subprovinces encompassing the districts represents an improvement of this biogeographical regionalization.