Edmund Reitter

Given the heightened vulnerability of deserts to climate change, this study aims to provide a comprehensive analysis of avian species diversity across ten global deserts to identify distinct diversity gradients and relatedness. Identify the difference from global patterns in avian migratory proportions and the underlying drivers for assessing the vulnerability and resilience of these desert ecosystems. Crowd-sourced avian diversity data of 2374 species from GBIF.org was used as a key analytical tool to study the diversity gradient across the ten major deserts. The variance in correlation patterns between avian ecological and behavioral traits across deserts were analyzed employing data of 1930 common avian species from AVONET. The analysis included comparisons of bird diversity, migratory patterns and trophic niches between Tropic of Cancer (TCan) and Tropic of Capricorn (TCap) deserts. Significant variations in bird diversity among the deserts were found. Deserts near the TCan exhibited higher bird diversity than in TCap deserts. TCan deserts had a higher prevalence of migratory species, facilitated by a broader niche breadth among sedentary species, which reduces niche competition and allows the influx of migratory invertivores. Proportion of migratory birds is higher in TCan deserts due to wider trophic niche but is significantly lower than the global average for the same latitude range. The findings highlight the need for targeted conservation strategies to protect avian diversity in the TCan deserts and mitigate extinction risks in TCap deserts, ensuring the resilience of these critical ecosystems.

Insects are the most diverse group of organisms, but their large number of species and the lack of specialists to study them have made this group particularly vulnerable to the main limitations in biological diversity, such as the Wallacean deficit. This study will contribute to the geographical knowledge of an insect trophic guild that has been widely used as an indicator group, the Scarabaeoidea and Silphidae copro-necrophagous beetles, emphasizing their geographical distribution in two Mexican national parks (Iztaccíhuatl-Popocatepetl and La Malinche) and the intermediate region, which includes sky-island ecosystems in central Mexico. Geographic records of the 32 species that have been previously recorded in the study region were compiled and used to generate potential distribution models aiming to generate potential alpha (species richness) and beta (total beta diversity, nestedness and replacement) diversity maps. The greatest predicted species richness was found between 3,000 and 3,500 m a.s.l. in the study region. Potential species richness ranged from 2 to 24 species. Total beta diversity was low in the study region (mean 0.1), while nestedness was the most important component of beta diversity (0.8). The maximum alpha and beta diversity values were predicted outside the national parks. Consequently, we consider that the studied national parks are not able to protect completely the regional alpha and beta diversities by themselves. Implications for insect conservation: Our results show that the highest alfa and beta diversity values of copro-necrophagous beetles might occur outside the national parks, and a suitable way to protect them could be the Archipelago reserve model as an alternative to protect the regional diversity.

Lucanus cervus (L.), the stag beetle, is a saproxylic beetle species distributed widely across Europe. Throughout its distribution the species has exhibited pronounced declines and is widely considered threatened. Conservation efforts may be hindered by the lack of population genetic data and unders…