Data from: Towards a functional understanding of species coexistence: ecomorphological variation in relation to whole-organism performance in two sympatric lizards

1. We examined intra- and interspecific variation in functional morphology and whole-organism performance in a sympatric lizard species pair, Iberolacerta horvathi and Podarcis muralis, in the area with a high potential for competition. 2. The biggest variation between species was found in two functional traits, bite force and climbing speed, linked with corresponding morphological traits. 3. The species with larger and taller heads, P. muralis, exhibited correspondingly stronger bite forces. The other species exhibited smaller and flatter head. Both traits may potentially promote segregation between species in trophic niche (stronger bites relate to harder prey) and in refuge use (flatter heads allow using narrower crevices, hence, influencing escaping from common predators). Stronger bites and larger heads also provide one species with a dominant position in interspecific agonistic interactions. 4. Females had longer trunks that impacted negatively on climbing speed, which may lower anti-predator escape abilities of the more trunk-dimorphic species, but positively influence reproductive effort. 5. Our results exemplify how the joint examination of morphological and functional traits of ecologically similar and sympatric species can provide a mechanistic background for understanding their coexistence, namely syntopic populations that are frequent in the study area. 6. The identified roles of functional morphology in this system of sympatric rock lizards support the contribution of functional diversification for the complexity of community structure via coexistence.

1. 本研究在具备高种间竞争潜力的区域内，针对同域分布的霍瓦蒂岩蜥（Iberolacerta horvathi）与普通壁蜥（Podarcis muralis）这一物种对，系统考察了二者功能形态学及整体有机体性能的种内与种间变异。2. 两类物种间的最大差异体现在两项功能性状——咬合力与爬行速度上，且这两项性状均与对应的形态学特征存在显著关联。3. 头部更大且更高的普通壁蜥（P. muralis），其咬合力也相应更强；而另一物种则拥有更小且更扁平的头部。上述两类性状或可推动两个物种在营养生态位（较强咬合力对应更坚硬的猎物）以及避难所利用（更扁平的头部可进入更狭窄的缝隙，进而影响其躲避共同捕食者的能力）方面的生态位分化。此外，更强的咬合力与更大的头部，还能让其中一个物种在种间对抗性互动中占据优势地位。4. 雌性个体拥有更长的躯干，这会对爬行速度产生负面影响，进而降低躯干形态二态性更强的物种的反捕食逃逸能力，但同时对其繁殖投入存在积极影响。5. 本研究结果阐明，对生态位相似且同域分布的物种的形态与功能性状开展联合考察，能够为理解其共存机制提供机理层面的支撑，而这类同域种群在本研究区域内分布十分常见。6. 本研究针对同域分布岩蜥类群所揭示的功能形态学作用，证实了功能分化可通过物种共存过程，推动群落结构的复杂性提升。