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

The environmental impact assessment (EIA) is a nearly universal instrument intended to limit or to offset the environmental tolls of development projects.  Here, I describe some of the key shortcomings of EIAs in terms of their real-world application, especially in developing nations that harbor much of the world’s imperiled biodiversity.  A surprisingly large number of EIAs suffer from major inaccuracies and some are green-lighting projects that will have serious environmental and societal costs.  I summarize by proposing eight strategies to help improve the conservation capacities of EIAs.

Global climate change occurs from both natural and anthropic causes.  Anthropic climate change has effects at various scales and occurs faster than the adaptation of species to these changes.  Protected natural areas have been created to preserve species from the different threats facing them.  Sierra La Laguna is a sky island with almost no anthropic pressure given its natural isolation; it is home to several endemic taxa, including Peromyscus truei lagunae and Sorex ornatus lagunae.  This study aims to assess the possible impact of climate change on species endemic to a sky island exposed to virtually no local anthropic pressure.  The Sierra La Laguna sky island, located in the southern region of the Baja California peninsula, harbors different vegetation types, including an oak-pine forest at the highest elevations and xeric vegetation at lower ones.  Ecological niche models were developed under three climate change scenarios contemplating temperature rises of 1.5 °C and 4.4 °C.  There are insufficient localities to make statistically robust models for mammalian species.  Therefore, we used plant species typical of the oak-pine forest (Pinus cembroides lagunae, Quercus brandegeei, and Q. devia) and the rodents Peromyscus eva, that thrives in dry deciduous forests, and Chaetodipus rudinoris and C. spinatus, associated with xeric ecosystems.  The models show that ecological suitability for the oak species decreases, while it is completely lost for the pine species.  On the other hand, P. eva broadens its elevational range, while C. rudinoris and C. spinatus increase their ecological suitability in both area and elevation.  The Sierra La Laguna sky island is an area with virtually no regional or local anthropic pressure.  Nonetheless, the projections conducted under various climate change scenarios show a loss of up to 100 % of the area of climatic and elevational suitability for species characteristic of the oak-pine forest even with the minimum temperature rise of 1.5 °C.  These results suggest that, under these conditions, endemic species such as P. t. lagunae and S. o. lagunae will become extinguished despite the absence of local anthropic pressures.

Based on a revision of historical and taxonomic accounts, we showed that Felis fasciatus Larrañaga, 1923, represents the oldest available Linnean name referable to the pampas cat endemic to the Uruguayan Savannah ecoregion, currently regarded as Leopardus munoai (Ximénez 1961).  To anchor the name Felis fasciatus to Uruguayan specimens, we designated a neotype for this taxon with terra typica in Estancia San Cristóbal, Arroyo Limetas, Conchillas, Department of Colonia, Uruguay.  Since Larrañaga's fasciatus represents a senior synonym of L. munoai, it takes precedence and, in compliance with the International Code of Zoological Nomenclature, it must therefore be used to refer to the "Uruguayan" pampas cat, L. fasciatus (Larrañaga 1923), for which we suggested the vernacular name "Larrañaga’s pampas cat".

Decades ago, a multi-factor perspective offered valuable insights into the causes of population cycles in arvicoline (= microtine) rodents.  Multi-factor perspectives are also critical for understanding the ecology of infectious diseases.  Here, we provide examples of how these perspectives inform our ability to predict variation in disease risk through space and time.  We focus in particular on the evidence that many emerging zoonotic pathogens of humans have multiple hosts rather than just one, that most host species harbor more than one pathogen and that these pathogens interact, and that understanding variation in the abundance of species that transmit pathogens often requires deep exploration of the ecological community in which those hosts are embedded. 

The rutting season of the white-tailed deer (Odocoileus virginianus) is seasonal in North America, but in tropical latitudes it occurs year-round with peaks locally variable. Reproductive cycle of this species in Costa Rica is variable, clearly seasonal in San Lucas Island but continuous with two birth peaks in Palo Verde and Santa Rosa national parks in northwestern Costa Rica. In Hacienda y Refugio de Vida Silvestre Curú in the Nicoya Peninsula, a site south of these parks but in a different life zone, we observed males with hard antlers in 2015 but only from July to November. We therefore hypothesized that white-tailed deer have a continuous reproductive cycle during the year in Curú because the rainfall pattern is the same as in Palo Verde and Santa Rosa. We visited Curú every month and recorded the status of white-tailed deer antler growth: nubs, velvet, and hard, from January 2016 to December 2019. We also recorded other rut behaviors and the presence of spotted fawns. We recorded 1,134 observations of the status of antler growth, 13 observations on reproductive behavior and 133 observations of spotted fawns. The antler cycle was seasonal in the four years of study. Male antler casting took place from mid-November to mid-February and the growth of new antlers began in mid-December and lasted until mid-March. Velvet shedding occurred in April, May and June, and by July males had hard antlers. The rutting season lasted three months from mid-June to mid-August. Small spotted fawns were observed from the middle of the dry season to the beginning of the rainy season. All this highly contrasts with the reproduction pattern observed in Santa Rosa. Lack of seasonal variation in the photoperiod is likely an important factor that allows deer to reproduce throughout the year in these protected areas, but this variation does not exist in Curú either, where the species is seasonal. The reproductive patterns of white-tailed deer in Central and South America may have evolved in response to seasonal fluctuations in specific food availability, competition, or predation, all of which may be directly related to rainfall patterns. Greater knowledge of the link between rainfall patterns and food availability for deer would be of great help to further our understanding of factors driving the reproduction cycle of the White-tailed deer.

Protected areas are frequently established to prevent declines in biodiversity, but their effectiveness in preserving biodiversity can depend on how land outside their borders is managed.  We evaluated how land use changes from 1989 to 2016 in the Reserva de la Biosfera Sierra del Abra Tanchipa (RBSAT) landscape might affect the role of the RBSAT for conservation of biodiversity, with an emphasis on conservation of jaguars, a keystone species.  We estimated the rate of land use change within and surrounding the RBSAT, a 215 km2 natural reserve in San Luis Potosí, Mexico, from 1989 to 2016 using supervised classifications of satellite imagery.  We also analyzed the distribution of two GPS collared male jaguars.  The RBSAT and surrounding landscape became increasingly fragmented and impacted by human use over the previous ca. 30 years.  The largest increases were seen in infrastructure and intensive agriculture, while the largest decreases were seen in pasture, tropical deciduous forest, and secondary vegetation.  Jaguars were located more frequently than expected in secondary vegetation, the most common cover class, which decreased from 34.8 % of the landscape to 32.1 % by 2016.  Only 23 % of jaguar locations fell within the boundaries of the RBSAT, due to increases in preferred habitat attributes of jaguars and prey outside the Reserve.    Increasing fragmentation compromises the RBSAT’s role as a biodiversity reserve, especially for interior-dependent species. Fragmentation and edge habitats in combination with increasing agriculture enhance suitability of the landscape surrounding the RBSAT for prey of jaguar, and only 23 % of jaguar locations were within the RBSAT itself.  This increases the likelihood of jaguar-related conflicts in surrounding communities.  Regional landscape planning should include policies that incentivize practices that maintain remaining larger habitat patches and minimize the likelihood of human-wildlife conflicts. 

The physiographic, climatic, and ecological characteristics of the mountainous regions of Oaxaca are unique and host geographically isolated populations of Peromyscus mexicanus.  Populations of P. mexicanus from the Sierra Madre del Sur in the Gulf side (SMG) and Pacific side (SMP), Oaxaca, were compared at the craniodental and molecular genetic levels (cytochrome b sequences).  The geographic isolation of both sides of the Sierra Madre del Sur are expected to have led to genetic isolation between populations of P. mexicanus in each area and from populations of eastern México.  Our results show that the Oaxacan SMG and SMP populations are genetically different, as are populations of eastern México.  Populations in the Oaxaca SMG-SMP are more genetically similar to P. gymnotis than to P. mexicanus from eastern México.  We recommend that the Oaxacan SMG population be classified as P. totontepecus and the SMP population as P. angelensis, with the Putla population, which is morphologically and morphometrically different, as the subspecies, P. a. putlaensis.

The Pacific region, one of the most disturbed areas in México, is home to the pygmy spotted skunk (Spilogale pygmaea), a local endemic species and one of the smallest carnivores in the world.  This small carnivore is currently listed as a species subjected to special protection in México and the International Union for Conservation of Nature.  The objective of this work was to model environmental suitability and estimate the potential distribution of S. pygmaea in México.  Predictive models were created using climatic, anthropic, and topographic variables with the Maxent tool.  Models were assessed through partial Receiver Operating Characteristic (ROC) performance by omission rate and AUC.  Finally, land use within the predicted potential area (potential distribution) was analyzed using the 2015 land cover layer of México issued by CONABIO.  According to the model, S. pygmaea has a potential distribution from southern Sinaloa to Chiapas, comprising Michoacán and Guerrero towards the Balsas River basin in relation to dry forests.  The predicted area was 95,600 ± 0.02 km2, representing a restricted distribution in México.  Many localities have low environmental suitability (<0.4) and ecosystem modification and fragmentation, mainly influenced by livestock density.  Spilogale pygmaea may be considered rare due to the lack of sampling, which jeopardizes the conservation of this group given its fragmented habitat.  Additionally, S. pygmaea is attracted to areas with human settlements, potentially leading to human-animal conflicts.  Natural areas, along with information sharing on the presence and importance of the species in nearby communities, may be an effective strategy to benefit this small carnivore.

 Carnivores are extremely important in ecosystem dynamics.  Coatis (Procyonidae) are a group of Neotropical species with highly developed social behavior.  One coati species is the Central American or white-nosed coati (Nasua narica).  This work describes the analysis of two sets of mitochondrial data for a sample of N. narica covering most of the geographic distribution range of the species.  The first data set analyzed 74 specimens for three mitochondrial loci; the second, 59 specimens for complete mitochondrial genomes.  Our phylogenetic analyses revealed six distinct genetic groups of N. narica in southern México, Central America, and South America, which, together with three additional groups found in northern México and southern USA in a previous study, resulted in a total of nine genetically distinct groups of N. narica.  The first genetic group (G1), which began to differentiate 4.1 to 3.2 million years ago, was located on the Pacific coast of Ecuador and northern Colombia.  A second genetic group (G6) was detected in northern Colombia, Panama, and southern Costa Rica, being introgressed by mitochondrial DNA from the mountain coati (Nasuella olivacea).  The third genetic group (G3) was located in Costa Rica, Nicaragua, El Salvador, Honduras, and southern Guatemala.  The fourth genetic group (G4) was located in north-central Guatemala and Belize.  The fifth genetic group (G5) was distributed in southern México (Chiapas, Tabasco, Campeche, Quintana Roo, and Yucatán) and northern Guatemala.  Finally, the sixth genetic group (G2) was found only in Mérida (Yucatán, México).  Groups G2 to G5 became mitochondrially diversified over 1.9 to 1.1 million years.  All groups showed high mitochondrial genetic diversity, although the South American genetic group (G1) had the highest diversity.  The northern genetic groups (G4, G5) had lower genetic diversity, except for the Merida group, which is likely composed of other undetected subgroups.  The existence of six (nine, considering another study) well-developed groups in N. narica is related to female phylopatry and climatic changes during the Pleistocene.  A spatial autocorrelation analysis showed a very high structure, well in line with the south-to-north colonization of the American continent by N. narica.

The lesser long-nosed bat (Leptonycteris yerbabuenae) is a partially migratory, nectarivorous species that exhibits reproductive asynchrony across its range.  Both migratory and resident populations of sexually active males of L. yerbabuenae may form an odoriferous dorsal patch during their mating season.  This is created by smearing saliva, urogenital fluids, and anal secretions over the interscapular dorsal region with their feet.  Dorsal patches are believed to influence female mate choice.  We synthesized the sightings of male dorsal patches across the species’ range, including gathering new observations of male L. yerbabuenae with dorsal patches captured at the northern extent of their range and citing previously unreported observations that we obtained by contacting other researchers.  We also conducted a literature review to include all previously documented records of male L. yerbabuenae presenting dorsal patches.  We document the first observations of male L. yerbabuenae with dorsal patches in the southwestern United States.  In the Big Hatchet Mountains in New Mexico, we captured 1 male with a developed dorsal patch (i. e., bare dorsal skin with sticky fur) on 25 July 2019 and two others on the night of 13 August 2019.  New observations of males with developed dorsal patches were obtained from Hilltop Mine in Arizona (June 2006 or 2007) and at a hummingbird feeder at a residence near the Hilltop Mine (July 2013).  A male with a recovering dorsal patch (i. e., bare dorsal skin with regenerating fur) was also captured in a roost near Patagonia, Arizona, in late August 2008 and at a hummingbird feeder at a residence near Silver City, New Mexico (September 2021).  All previously published records of males with dorsal patches occurred in roosts in Mexico during known mating seasons.  These new observations suggest that L. yerbabuenae may breed in New Mexico and Arizona between June and August, but follow-up studies are needed to confirm this behavior.  Much of the reproductive biology of this important pollinator remains unknown.  Therefore, identifying regions where males present dorsal patches may not only assist in locating and protecting mating roosts, but would also further our understanding of the population ecology of this migratory species.