In desert ecosystems, arthropods such as scorpions are understudied, and sufficient information is still lacking regarding their biodiversity. Specimen collection was carried out over 24 months (2016–2017). This study assessed the phenology, abundance, richness and diversity of scorpion species in arid ecosystems of the Sahara desert of Algeria (Ghardaïa). It examined the potential influence of climate parameters (precipitation, temperature and wind) on activity density, diversity and the phenological distribution of the species among seasons. We identified eight Buthidae species: Androctonus aeneas, Androctonus amoreuxi, Androctonus australis, Buthacus samiae, Buthacus spinatus, Buthacus elmenia, Buthus saharicus and Lissothus chaambi. Androctonus amoreuxi and Androctonus australis were the most abundant and omnipresent species, comprising 54.41% and 33.82% of all species found, respectively. Shannon’s index and the evenness index demonstrated a very poor diversity of scorpions in this region and a poor balance between the number of sampled species. Seasonal variation and climate parameters, i.e., temperature and wind, influenced the number, distribution, and the diversity of scorpions. The number of species found in Ghardaïa Province represent more than 20% of the scorpion species reported in Algeria.

Summary. Assessing temporal changes of the distribution of threatened species is paramount for effective management. Threatened species are sensitive to environmental changes and can be extirpated rapidly due to climatic and anthropogenic effects. Here, we monitor the distribution of the locally critically endangered Urothemis edwardsii in northeastern Algeria where the species has been recovering during the last decade after being restricted to a single locality since the 1990s. During the flight seasons in 2018, 2019, and 2021, we conducted field surveys recording the number of males, females, and breeding pairs across 15 sites in northeast Algeria (El Taref province). We found the species at seven sites; reproduction was confirmed at four. In two of the sites, the species was newly recorded but showed no signs of reproduction. We confirmed the maintenance of the reproductive populations that were recently discovered. While the local conservation status of the species is better than that in the 1990s, there are still different threats that need to be addressed and conservation measures that should be implemented or reinforced to ensure maintenance as well as future expansion of the species.

Understanding the impact of climate change on waterbirds, particularly those of conservation concern, is essential for their long-term management and effective conservation. In arid regions such as North Africa, wetlands of international importance have been affected by severe drought events, but their impact on waterbirds is still not well understood. Here, we assess the population dynamics of four emblematic resident species (Aythya nyroca, Marmaronetta angustirostris, Oxyura leucocephala, and Porphyrio porphyrio porphyrio) in a North African Ramsar site (Garaet Hadj Tahar marsh, Northeast Algeria), and determine the climatic variables (temperature, precipitation, and drought index) that best predict the change in abundance in wintering and breeding seasons. We used a long-term survey of regular counts during the wintering and breeding seasons of 2002–2019. The temporal trend of waterbird abundance differed between species and seasons. Species showed different sensitivities to different climatic variables at different time windows preceding the wintering and breeding seasons. We found that the population dynamics of the endangered O. leucocephala in the wintering and breeding seasons were best predicted with the drought index, whereas those of P. p. porphyrio were best correlated with maximum temperature. Population dynamics during the wintering and breeding season of the two other species were best explained with either maximum temperature, precipitation, average temperature, or drought. Species responded differently to warming and drought. The most endangered species (O. leucocephala) showed population declines in drier years, whereas less threatened species (A. nyroca, M. angustirostris, and P. p. porphyrio) exhibited either positive or negative correlations. The observed temporal increase in vegetation cover was positively correlated with the wintering population size of O. leucocephala, as well as the breeding population size of P. p. porphyrio and M. angustirostris. These findings highlight the urgent need for climate-adaptive conservation strategies to sustain wetland biodiversity and ecosystem resilience in the face of increasing climate stressors, aligning with the global sustainability goals for biodiversity conservation and ecosystem management. Our results suggest that future increases in temperatures and drought severity might threaten endangered waterbirds and benefit more common species in the region.

Age is a critical intrinsic factor that influences the probability of survival of organisms on Earth. In many animals, the lifestyles and habitat occupancy of males and females are so different that the effect of age could be sex-dependent. To reveal such patterns in wild animal populations, we here use a natural population of the Mediterranean demoiselle Calopteryx haemorrhoidalis Vander Linden (Calopterygidae: Zygoptera) in Northeast Algeria to analyze the influence of age and sex on survival probability using daily capture–mark–recapture. We used stepwise model selection on Cormack–Jolly–Seber models that explain recapture and survival probability, including age and sex as covariates. We marked a total of 214 adults throughout the study period (41 days). The sex ratio did not deviate from unity. Recapture probability depended on sex and time, with a slightly higher recapture probability in males (0.30 [95% CI: 0.27–0.35]) than females (0.26 [0.22–0.30]). The survival probability was slightly higher in females (0.89 [0.86–0.91]) than males (0.86 [0.82–0.88]). The best model for the survival probability included an additive effect of sex and age, indicating that the survival probability of both sexes declined with age. Interestingly, the lifespan of some individuals reached 119–130 days, which is surprisingly long compared to other temperate damselflies.

Decreased ambient temperature and shorter reproductive seasons are the two main obstacles that ectotherms face at higher elevations. Studies have shown that some life history traits such as phenological windows of activity, duration, and fitness components vary as elevation increases. However, studies on the elevational gradient at the southern range limit of species are lacking. In this study, we aim at assessing some aspects of the life history of a spider species, the sprassid Micrommata ligurina (C.L. Koch, 1845), across an elevational gradient from 30 to 1030 m in Northeast Algeria. There was strong evidence of an elevational shift in the phenology of reproduction with a delay rate of 2.2 days per 100 m of elevation, and the three quantiles of the phenology (10, 50, and 90%) shifted with the same magnitude across elevation. In all sites from low to high elevation, the species showed a decrease in number of individuals. The mean number of eggs was 200 ± 35 eggs, and the mean number of hatching eggs was 110.9 ± 23.5 eggs. The clutch size at high elevation sites was higher than that of low-elevation sites, but in contrast, the hatching success was higher at lower elevation sites. Overall, the species exhibited clear elevational clines in life history traits and abundance, suggesting a high potential of plasticity. This work constitutes the first study carried out on spider species ecology in the region.