Autonomous University of Tlaxcala

Echolocation is a key sensory adaptation that can be influenced by changes in body mass (Mb). To cope with variation in ambient temperature (Ta) and food availability, some bat species increase Mb for hibernation while others reduce Mb to remain active and minimize energetic costs during winter. In bats that remain active year-round, such as Eptesicus fuscus, seasonal changes in Mb may affect echolocation traits. We examined the relationship between Mb, Ta, season, and four echolocation parameters —maximum frequency, peak frequency, minimum frequency, and bandwidth— in individuals captured during the dry-cold and dry-warm seasons in La Malinche National Park, a montane ecosystem in central Mexico, using mixed-effects models that explicitly accounted for atmospheric attenuation. Our results revealed a positive relationship between Mb and season and Ta, and a negative relationship between Mb and all four echolocation variables. These findings suggest that seasonal variation in Mb may influence acoustic signaling, with potential ecological implications. During the dry-warm season, larger bats with lower frequencies and narrower bandwidths may reduce acoustic resolution without substantially compromising foraging efficiency in prey-rich environments. In contrast, smaller bats with higher-resolution calls may enhance prey detection when sources are limited during the dry-cold season. To our knowledge, this is the first study to explore the sensory consequences of seasonal phenotypic flexibility in bats. Future research should include additional seasons and species and investigate physiological and morphological mechanisms underlying these seasonal adjustments.

Urbanization creates novel environmental conditions that challenge individual survival. The expansion of building areas, along with habitat loss and rising temperatures in urban areas, not only affect species diversity and composition, but often drive morphological, physiological, and functional changes either as adaptative responses or as outcomes of environmental stress. Such individual-level shifts in key traits can compromise critical ecosystem services like pollination. In this sense, orchid bees (Apidae: Euglossini) are essential pollinators in Neotropical ecosystems and could serve as excellent model organisms for studying whether potential effects of urbanization on morphology compromise specialized pollination services. In this study, we sampled orchid bee communities across 14 sites representing an urbanization gradient in a Neotropical city surrounded by cloud forest in Mexico. We estimated urbanization using satellite imagery, assessed a set of morphometric measurements in the five most abundant orchid bee species, and quantified pollination of Gongora galeata (Orchidaceae), a specialized orchid that is exclusively pollinated by Euglossa obrima. Whitin the euglossine assemblage, urbanization was associated with smaller body sizes (i.e. head width) and higher wing asymmetry, revealing developmental stress. In the case of E. obrima, wing asymmetry was associated with lower pollination probability of G. galeata. These findings suggest that urbanization drives morphological variation in orchid bees, and provide novel evidence that these changes may have consequences for orchid pollination, a fundamental ecosystem service provided by these specialized Neotropical bees.

Background: Although trauma can adversely affect body esteem, the specific impact of complex post-traumatic stress disorder (CPTSD) remains underexplored among Mexican women. Objective: This study examined body esteem among trauma-exposed controls and women with either PTSD or CPTSD in a sample of female Mexican university students. Method: Using a cross-sectional design, we recruited 657 cisgender Mexican women (aged 18-66) who completed the Body Esteem Scale (BES), International Trauma Questionnaire (ITQ), and Adverse Childhood Experiences-International Questionnaire (ACE-IQ). Participants were classified into three groups: trauma-exposed controls (n = 526), PTSD (n = 68), and CPTSD (n = 63). Results: Total BES scores differed significantly across groups. Participants with CPTSD reported lower overall body esteem (M = 99.48, SD = 21.32) compared to those with PTSD (M = 114.24, SD = 26.68) and controls (M = 119.38, SD = 24.93). Significant group differences also emerged in the Sexual & Physical Attractiveness and Physical Condition & Weight Concern subscales. Furthermore, the negative correlation between BES scores and trauma symptoms was more pronounced in the CPTSD group (rho = -0.40) than in the PTSD group (rho = -0.25). Conclusions: CPTSD is associated with significantly diminished body esteem in this population. These findings underscore the critical need for culturally sensitive, trauma-informed interventions that address both the psychological and somatic dimensions of body image.

Protected Natural Areas (PNA) are a primary tool for conserving biodiversity and are used internationally. However, there is currently no decree ensuring their proper functioning, especially considering the rapid expansion of human activities. In Mexico, 182 PNA have been decreed, of which 125 terrestrial areas were analyzed to assess fragmentation and connectivity using land cover data from the MAD-Mex system (Monitoring Activity Data for the Mexican REDD + program) and a least-cost path modeling approach. A cluster analysis based on fragmentation metrics resulted in the formation of three groups of PNA, which were classified through discriminant analysis into low, medium, and high vulnerability levels. Subsequently, the extreme groups (low and high vulnerability) were characterized using nine socioeconomic variables, through a generalized linear model. The most vulnerable PNA are concentrated in the central region of the country, where population density, mining activity, and proximity to metropolitan areas increase fragmentation and reduce connectivity. A generalized linear model showed that the vulnerability of PNA increases with human population density and the presence of mines, while it decreases with distance to metropolitan areas and the presence of tourist areas. This analysis provides important insights into the local threats faced by each of Mexico's terrestrial PNA. Such information is crucial for improving management plans and conservation strategies tailored to the specific threats confronting these areas.

Beta diversity patterns result from the assembly of communities shaped by local and regional filters. However, understanding these patterns is limited by gaps in species distribution knowledge, especially for hyperdiverse groups. In this context, ecological niche modelling represents an effective approach to overcoming such limitations by providing robust species distribution predictions. In this study, we used the distribution models of 67 scarab beetle species to assess patterns of beta diversity and its components (species turnover and nestedness) across 14 elevational gradients on the coastal and inland montane slopes of El Salvador. We also analysed the effects of climatic (environmental filter) and geographic (dispersal filter) factors on beta diversity. Our results show that beta diversity decreased with increasing elevation, independently of geographic region, and that there were no significant differences in the relative contributions of turnover and nestedness between coastal and inland gradients. Environmental filtering (differences in temperature and precipitation) and dispersal filtering (spatial distance) were determinants in shaping the beta diversity patterns. These results indicate that the beta diversity of scarab beetles is determined by climatic and geographic factors. This integrative approach based on species distribution modelling underscores the importance of montane habitats for maintaining beta diversity and endemic species, highlighting the role of environmental heterogeneity and geographic location in shaping ecological assemblages. These findings emphasize the broader need for conservation strategies that preserve ecological diversity in complex landscapes, particularly under threats of habitat loss and climate change.