Griselda Escalona-Segura

Phylogenetic Patterns in Montane Troglodytes Wrens

This is the publishers version, also available electronically from http://www.jstor.org/stable/1370013#references_tab_contents.

The Chimalapas Region, Oaxaca, Mexico: a high-priority region for bird conservation in Mesoamerica

The Chimalapas region, in eastern Oaxaca, Mexico, holds lowland rainforests, tropical dry forests, and cloud forests typical of the Neotropics, as well as montane pine and pine-oak forests more typical of the Nearctic. Totaling more than 600,000 ha, much of the region is forested, and in a good state of preservation. The Chimalapas avifauna is by far the most diverse for any region of comparable size in the country, totalling at least 464 species in the region as a whole (with more than 300 species in the lowland rainforest) representing 44% of the bird species known from Mexico. Within the region, the humid Atlantic lowlands hold 317 species, the montane regions 113 species, and the southern dry forested lowlands 216 species. Important species present in the region include Harpy Eagle Harpia harpyja and several other large eagles, Black Penelopina nigra and probably Horned Oreophasis derbianus Guans, Scarlet Macaw Ara macao , Cinnamon-tailed Sparrow Aimophila sumichrasti , Rose-bellied Bunting Passerina rositae , and Resplendent Quetzal Pharomachrus mocinno . The area holds immense lowland rainforests and cloud forests that rank among the largest and best preserved in all of Mesoamerica, including a complete lowland-to-highland continuum, with entire watersheds preserved more or less intact.

THE MEXICAN SHEARTAIL (DORICHA ELIZA): MORPHOLOGY, BEHAVIOR, DISTRIBUTION, AND ENDANGERED STATUS

Abstract We reviewed morphological variation, taxonomic status, geographic distribution, ecology, and behavior of the poorly known hummingbird, the Mexican Sheartail (Doricha eliza), based on museum specimens and field studies. Although the broadly disjunct distribution of the species would suggest that two taxa are involved, morphological differences between the populations appear minor, not deserving of formal taxonomic recognition. Ecological differences between the two populations are stronger, however; modeled ecological niches are nearly nonoverlapping, and ontogenetic and behavioral differences may exist. We recommend that, given its extremely restricted distribution, the Veracruz population be considered critically endangered, whereas the Yucatan population be designated as having a restricted range and accorded near-threatened status. RESUMEN.—Se revisaron la variación morfológica, estatus taxonómico, distribución geográfica, ecología y conducta de un taxón muy poco conocido, el colibrí tijereta mexicano (Doricha eliza), en base en estudios de campo y en museo. A pesar de que la amplia disyunción en su distribución geográfica sugiere la existencia de dos taxones diferentes, la diferenciación morfológica es mínima y no amerita reconocimiento taxonómico formal. Sin embargo, las diferencias ecológicas entre las dos poblaciones son más marcadas, con nichos ecológicos modelados que casi no se sobrelapan, y diferencias ontogenéticas y de conducta pueden existir. En general, la población de Veracruz debe ser considerada en peligro de extinción, mientras que la población de Yucatán debe ser designada de distribución restringida y con un estatus de conservación de casi amenazada.

Potential distribution and climatic niche of seven species of Campylorhynchus (Aves, Troglodytidae): conservation implications for C. yucatanicus

ABSTRACT Predictive species distribution models and environmental niche evaluation have become useful techniques in conservation biogeography and are increasingly used as prediction tools to identify priority conservation areas for focal species. Multiple hypotheses and paradigms were proposed to explain the variation seen in geographical range sizes among species. Our hypothesis was that in a monophyletic group of 7 Campylorhynchus species, those with a broad climatic niche would persist over a wide geographic range while species with a narrow climatic niche, such as C. yucatanicus, would be restricted to a smaller geographic range. To test this hypothesis, we modeled potential distributions using the MaxEnt algorithm and estimated the climatic niche of 7 species included in the monophyletic group of Campylorhynchus (Troglodytidae). To compare the ecological niches of these 7 species, we plotted the occurrence density for each species with combinations of environmental conditions and then identified the first 2 components using a principal component analysis. In general, the most important variables predicting species presence were rainfall seasonality and minimum temperature during the coldest month. The climatic niches for these 7 species were relatively segregated throughout the environmental space. When compared with related species, C. yucatanicus had the narrowest niche width and lowest niche similarity and overlap index, which could explain the restricted distribution for this species. Given the restricted range of C. yucatanicus within the Yucatan Peninsula, the species is highly vulnerable to small disturbances, current local threats (e.g., habitat alterations due to urbanization), and global threats (e.g., climate change). We therefore recommend increased national and international protection for C. yucatanicus and that it be listed as globally threatened by the International Union for Conservation of Nature (IUCN). Received 22 June 2016. Accepted 9 June 2017.

CracidMex1: a comprehensive database of global occurrences of cracids (Aves, Galliformes) with distribution in Mexico

Abstract Cracids are among the most vulnerable groups of Neotropical birds. Almost half of the species of this family are included in a conservation risk category. Twelve taxa occur in Mexico, six of which are considered at risk at national level and two are globally endangered. Therefore, it is imperative that high quality, comprehensive, and high-resolution spatial data on the occurrence of these taxa are made available as a valuable tool in the process of defining appropriate management strategies for conservation at a local and global level. We constructed the CracidMex1 database by collating global records of all cracid taxa that occur in Mexico from available electronic databases, museum specimens, publications, “grey literature”, and unpublished records. We generated a database with 23,896 clean, validated, and standardized geographic records. Database quality control was an iterative process that commenced with the consolidation and elimination of duplicate records, followed by the geo-referencing of records when necessary, and their taxonomic and geographic validation using GIS tools and expert knowledge. We followed the geo-referencing protocol proposed by the Mexican National Commission for the Use and Conservation of Biodiversity. We could not estimate the geographic coordinates of 981 records due to inconsistencies or lack of sufficient information in the description of the locality. Given that current records for most of the taxa have some degree of distributional bias, with redundancies at different spatial scales, the CracidMex1 database has allowed us to detect areas where more sampling effort is required to have a better representation of the global spatial occurrence of these cracids. We also found that particular attention needs to be given to taxa identification in those areas where congeners or conspecifics co-occur in order to avoid taxonomic uncertainty. The construction of the CracidMex1 database represents the first comprehensive research effort to compile current, available global geographic records for a group of cracids. The database can now be improved by continuous revision and addition of new records. The CracidMex1 database will provide high quality input data that could be used to generate species distribution models, to assess temporal changes in species distributions, to identify priority areas for research and conservation, and in the definition of management strategies for this bird group. This compilation exercise could be replicated for other cracid groups or regions to attain a better knowledge of the global occurrences of the species in this vulnerable bird family.