Parental Care and Nesting Selection

Environmental variation can drive the evolution of morphology through selection on performance traits such as bite force, which is critical for prey use, competition, defense, and mating in lizards. On Orchid Island, long-tailed skinks (Eutropis longicaudata) face intense egg predation from (Oligodon formosanus) and uniquely exhibit parental care. We tested whether these skinks have stronger bite force than populations without egg guarding. Three hypotheses were examined: (1) Orchid Island skinks have higher bite force due to parental care; (2) males show greater bite force than females due to sexual selection; and (3) head morphology predicts bite force. Results show Orchid Island skinks possess stronger bites, likely linked to predation pressure and parental behavior. Males exhibit higher bite force, and body mass and head size positively correlate with performance.