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

Posted by
  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...

One small step for citizens, one giant leap for science: iNaturalist records boost our understanding of the evolution of parental care in a clade of arachnids

Posted by

 


One small step for citizens, one giant leap for science: iNaturalist records boost our understanding of the evolution of parental care in a clade of arachnids 

Abstract

Citizen-science platforms have become powerful tools for documenting natural history, but their potential for reconstructing behavioural evolution remains largely unexplored. Here, we combine field and laboratory records with a systematic survey of iNaturalist observations to investigate the evolution of parental care in the superfamily Gonyleptoidea, the clade containing the most documented cases of care in harvestmen. We report 85 new records of parental behaviour (78 of maternal or paternal care and seven of no care), more than doubling the number of species with available data. These records, together with all published information, were mapped on to a newly assembled supertree of 165 species spanning nine families. Transition rates revealed that maternal care arises exclusively from ancestors without care, whereas paternal care evolves through two routes—from no care and from maternal care—suggesting distinct selective pressures underlying its repeated origins. Transitions from parental care back to no care are frequent in both sexes, suggesting that alternative egg-protection strategies (e.g. oviposition in cryptic sites and debris coverings) may compensate for the absence of parental attendance, while avoiding the costs of prolonged care. Our findings highlight the remarkable evolutionary lability of parental care in Gonyleptoidea and demonstrate that citizen-science data can substantially accelerate macroevolutionary research.

Machado, G., Buzatto, B. A., Caetano, D. S., Flores, E., García-Hernández, S., Grob, O., Grossel, L. A., Höfer, H., Kury, A. B., Lancheros, H., Medrano, M., Oyarzún, C., Pérez-Schultheiss, J., Pinto-da-Rocha, R., Robledo-Ospina, L. E., Sáenz-Mancheno, J., Solano-Brenes, D., Quesada-Hidalgo, R., Triana, E., . . . Villarreal, O. (2026). One small step for citizens, one giant leap for science: INaturalist records boost our understanding of the evolution of parental care in a clade of arachnids. Zoological Journal of the Linnean Society, 207(2). https://doi.org/10.1093/zoolinnean/zlag061