Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon

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  Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon Abstract Snakes exhibit extreme cranial kinesis that facilitates ingestion of prey with large cross-sectional area, but this ability is widely predicted to reduce bite performance due to decreased structural rigidity. Consequently, most large-bodied snakes rely on envenomation or constriction to subdue prey prior to ingestion. Species within the genus Drymarchon represent a notable exception: these large, non-venomous, non-constricting snakes routinely consume a wide range of prey, including large and potentially dangerous vertebrates, using only simple seizing and pinioning behaviors. Here, we quantify bite performance in three species of Drymarchon ( D. corais, D. couperi, and D. melanurus ), examine morphological predictors of biting performance, compare biting pressure to constriction pressure in similarly sized snakes, and synthesize dietary records across the genus. Our results sh...

Assessing the current and future distribution of Androctonus mauritanicus in Morocco under climate change using MaxEnt with environmental variables

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Assessing the current and future distribution of Androctonus mauritanicus in Morocco under climate change using MaxEnt with environmental variables

Abstract

Androctonus mauritanicus is among the most dangerous endemic scorpions in Morocco and poses a major public health concern due to its highly toxic venom and anthropophilic nature. This study assesses the current and future distribution of Androctonus mauritanicus under climate change to guide risk management strategies. The current and future distributions of A. mauritanicus were modeled using the MaxEnt algorithm based on occurrence data and environmental variables. Future projections were generated using an ensemble of three Global Climate Models (BCC-CSM2-MR, HadGEM3-GC31-LL, and MIROC6) under three Shared Socioeconomic Pathways (SSP126, SSP245, and SSP585). Model calibration was performed using ENMeval with spatial block cross-validation. The optimal model (LQH, RM = 2) showed high predictive performance, with a training AUC of 0.943, a validation AUC of 0.828 ± 0.182, a mean five-fold AUC of 0.923 ± 0.017, and a mean TSS of 0.689 ± 0.087. The current distribution revealed a concentration of suitable habitats in northern and central Morocco, whereas most southern, south-eastern, and eastern regions were classified as unsuitable. Analysis of environmental variables identified soil moisture and climatic variables (BIO03, BIO02, and BIO08) as the main factors shaping species distribution. Future projections suggested an expansion of suitable habitats under all climate change scenarios. Change detection analysis revealed positive net habitat gains ranging from 26.99% to 33.81%, with expansion areas consistently exceeding contraction areas. These results identify areas environmentally suitable for A. mauritanicus and demonstrate the value of species distribution models for surveillance and prevention planning.
Namiq, S., Namous, M., El Mourid, A., Bouimeja, B., & Touloun, O. (2026). Assessing the current and future distribution of Androctonus mauritanicus in Morocco under climate change using MaxEnt with environmental variables. Toxicon, 281, 109212. https://doi.org/10.1016/j.toxicon.2026.109212