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.

Clutch size is an important fitness component often quantified artificially by inducing oviposition in libellulid females. Female behavior and egg production of the yellow-veined skimmer, Orthetrum nitidinerve, were studied in northeast Algeria during its reproductive season. Data on reproductive behavior and biology of this Mediterranean endemic species has not been published previously. Males guarded territories within the wetland while females came only to lay their eggs and then went back to terrestrial habitat. In this study we induced oviposition, which depletes all the female eggs, to obtain estimations of egg deposition rate and subsequently clutch size. On average an induced clutch was ca. 2200 eggs while a natural one was about 970 eggs. Artificial clutches were positively correlated to body length but negatively related to mature lifespan. The rate of egg deposition was higher in the afternoon than in the morning, probably because of differences in temperature. During their mature lifespan females oviposited between one and three artificial clutches.

To assess potential health risks from heavy metal exposure through raw cow’s milk, we investigated lead (Pb) and cadmium (Cd) levels in milk samples from eastern Algeria using atomic absorption spectrometry and estimated dietary risks for adults and children. In 2021, 99 milk samples were collected from various regions. Average Pb and Cd levels were 0.332 ± 0.097 and 0.016 ± 0.011 mg kg⁻¹, respectively, with Pb exceeding the MRL in 99% and Cd in 87% of samples. Estimated daily intake (EDI) values for both metals were below established limits, indicating acceptable average exposure levels. However, the Target Hazard Quotient (THQ) and Hazard Index (HI) assessments revealed significant concerns. For adults, THQ and HI remained below 1, and carcinogenic risk (CR) values for Pb were below 10⁻⁴. In children, Cd posed minimal risk (THQ < 1), but Pb was problematic. While average THQ for Pb was below 1, 39% of samples exceeded this limit. HI for both metals surpassed 1 in 51% of samples, and CR for Pb exceeded 10⁻⁴ in 17 samples. These findings highlight the need for further analysis of milk from various Algerian regions to ensure consumer safety.

The white-headed duck is a globally threatened species and its populations have become fragmented and undergone major decline in recent decades. Changes including long-term abundance (five times from 2005 to 2018) and diurnal activity budget (2010−2011 and 2017−2018) with respect to the effect of habitat features at Boussedra marsh (unprotected area) were compiled in order to fill some gaps in the status and trend of North African populations. The population size of the white-headed duck decreased over years from 2010 to 2018 by about 52.81%, and was positively associated with interior vegetation area, but not significantly with water surface area. Trends of population dynamics differed among seasons, and the number was higher in wintering than breeding season. Sleeping (44.93%, 23.74%) and feeding (59.09%, 27.43%) were the dominant diurnal activities at both the years of study, respectively. Boussedra marsh plays an important ecological role as a diurnal forging habitat and reproduction site for this threatened species and as a shelter for other waterfowl.