Alberto E. Rojas-Martínez

Ecological relationships between columnar cacti and nectar-feeding bats in Mexico

A bibliographical and herbarium investigation on the pollination syndrome of Mexican columnar cacti (tribe Pachycereeae) was conducted. Most Mexican species of columnar cacti show a chiropterophilic-pollination syndrome and they flower synchronously in March to May. The floral biology, reproductive system and visitors (to both fruits and flowers) of Neobuxbaumia tetetzo , the most abundant and dominant columnar cactus of succulent forest in the Tehuacan Valley, were studied. This species reached densities of c. 1200 individuals ha −1 . The bats Leptonycteris curasoae and Choeronycteris mexicana were its only pollinators, whilst a more diverse array of visitors disperse seeds. Contrary to findings for multiple pollinators of columnar cacti in extratropical deserts in North America, the relationships between N. tetetzo and nectar-feeding bats was strong and tightly coupled in Mexico.

Deforestation Impacts on Bat Functional Diversity in Tropical Landscapes

Functional diversity is the variability in the functional roles carried out by species within ecosystems. Changes in the environment can affect this component of biodiversity and can, in turn, affect different processes, including some ecosystem services. This study aimed to determine the effect of forest loss on species richness, abundance and functional diversity of Neotropical bats. To this end, we identified six landscapes with increasing loss of forest cover in the Huasteca region of the state of Hidalgo, Mexico. We captured bats in each landscape using mist nets, and calculated functional diversity indices (functional richness and functional evenness) along with species richness and abundance. We analyzed these measures in terms of percent forest cover. We captured 906 bats (Phyllostomidae and Mormoopidae), including 10 genera and 12 species. Species richness, abundance and functional richness per night are positively related with forest cover. Generalized linear models show that species richness, abundance and functional richness per night are significantly related with forest cover, while seasonality had an effect on abundance and functional richness. Neither forest cover nor season had a significant effect on functional evenness. All these findings were consistent across three spatial scales (1, 3 and 5 km radius around sampling sites). The decrease in species, abundance and functional richness of bats with forest loss may have implications for the ecological processes they carry out such as seed dispersal, pollination and insect predation, among others.

Beta Diversity in a Highly Heterogeneous Area: Disentangling Species and Taxonomic Dissimilarity for Terrestrial Vertebrates

Quantifying differences in species composition among communities provides important information related to the distribution, conservation and management of biodiversity, especially when two components are recognized: dissimilarity due to turnover, and dissimilarity due to richness differences. The ecoregions in central Mexico, within the Mexican Transition Zone, have outstanding environmental heterogeneity and harbor huge biological richness, besides differences in the origin of the biota. Therefore, biodiversity studies in this area require the use of complementary measures to achieve appropriate information that may help in the design of conservation strategies. In this work we analyze the dissimilarity of terrestrial vertebrates, and the components of turnover and richness differences, among six ecoregions in the state of Hidalgo, central Mexico. We follow two approaches: one based on species level dissimilarity, and the second on taxonomic dissimilarity. We used databases from the project “Biodiversity in the state of Hidalgo”. Our results indicate that species dissimilarity is higher than taxonomic dissimilarity, and that turnover contributes more than richness differences, both for species and taxonomic total dissimilarity. Moreover, total dissimilarity, turnover dissimilarity and the dissimilarity due to richness differences were positively related in the four vertebrate groups. Reptiles had the highest values of dissimilarity, followed by mammals, amphibians and birds. For reptiles, birds, and mammals, species turnover was the most important component, while richness differences had a higher contribution for amphibians. The highest values of dissimilarity occurred between environmentally contrasting ecoregions (i.e., tropical and temperate forests), which suggests that environmental heterogeneity and differences in the origin of biotas are key factors driving beta diversity of terrestrial vertebrates among ecoregions in this complex area.

Effects of seed ingestion by the lesser long-nosed bat Leptonycteris yerbabuenae on the germination of the giant cactus Isolatocereus dumortieri

Abstract Bats have been considered efficient seed dispersers of columnar cactus (Isolatocereus dumortieri). However, to date, very little is known about the effect of seed ingestion by bats on seed germination. We carried out some germination assays for seeds of the cactus I. dumortieri obtained directly from fruits and fecal clumps of the endangered lesser long-nosed bat (Leptonycteris yerbabuenae) in a semiarid zone, within the Biosphere Reserve Barranca of Metztitlán in Central México. Additionally, we evaluated seed deposition patterns by bats. We found that 61.7% of the removed seeds were dispersed in fecal clumps, whereas the remaining seeds were spitted as single seeds. We also found that ingestion diminished seed germination by 65%. Under these conditions, seeds deposited individually around the mother plant may be of importance for local restoration and have the function of reforesting the locality, whereas ingested seeds can reach long distances and colonize new areas.

First Record of Jaguar (Panthera onca) from the State of Hidalgo, México

Abstract. We documented the first record of jaguar (Panthera onca) in the state of Hidalgo, México. With this record, the gap in the distribution of jaguar between San Luis Potosí and northwestern Puebla is reduced. In July 2013, we found 2 tracks on a trail in a pine-oak forest, and in October, we photographed a jaguar in an oak forest. Both sites are located within the Parque Nacional Los Mármoles in Sierra Gorda of Hidalgo. These records represent the first evidence of the presence of jaguar in Hidalgo, which is among the few states where all 6 species of felids that inhabit México occur.

New records of vespertilionid bats in the state of Hidalgo, Mexico

Abstract We recorded for the first time the species Rhogeessa alleni in the state of Hidalgo, Mexico, and registered the third locality for Myotis californicus. The bats were caught between March 2010 and September 2012. Specimens were preserved in skin, skull, and parts of skeleton and were deposited at the Colección Mastozoológica of Centro de Investigaciones Biológicas, Universidad Autónoma del Estado de Hidalgo. We provide external and cranial measurements as well as information about reproductive condition and habitat of each specimen.

Registros notables de mamíferos terrestres del estado de Hidalgo, México. Noteworthy records of terrestrial mammals from state of Hidalgo, Mexico

Documentamos la presencia de nueve especies de mamiferos poco conocidos para el estado de Hidalgo. Los ejemplares fueron capturados o registrados durante los muestreos realizados entre noviembre de 2007 y mayo de 2011, asi como entre enero y abril del 2015 en 28 municipios de Hidalgo. Para cada especimen aportamos informacion sobre la distribucion, medidas somaticas, condicion reproductiva y el habitat. Seis de las nueve especies representan el primer registro para el estado: Leopardus wiedii, Eira barbara, Lontra longicaudis, Orthogeomys hispidus, Peromyscus beatae y Peromyscus hylocetes