Abstract:
The environment of an organism exerts selective pressures that affect mobility, feeding, reproduction as well as predator-prey and conspecific interactions. Land use changes induced by human activities modify these selective pressures and may result in the adaptation of organisms. Amphibians are ectotherms that typically show a biphasic life cycle with an aquatic and terrestrial phase, which makes them particularly sensitive to environmental change. We studied the impact of habitat modifications on palmate newt populations in the Ile de France region across four types of habitats: urban, mixed, agricultural, and natural with at least two replicates for each habitat type. We measured the morphology of newts using callipers, quantified maximal running and swimming speed and acceleration using high-speed video recordings, and quantified the swelling of the hind limb linked to an inflammatory reaction. Our results show that in urban habitats, newts are larger and heavier and have a better body condition. Females, moreover, have a larger head in natural habitats, possibly due to diet specialisation of females during the breeding season. In mixed and agricultural habitats, newts have longer limbs and show a tendency to run faster, possibly associated with the selective pressures on movement in mixed habitats. Differences in inflammatory responses were observed between sexes but not habitat types. Overall, our results show differences in morphology and trends for differences in performance in newts living in different habitats suggesting that animals are adapting to human-induced changes in their environment.
摘要:
有机体的环境施加影响移动性的选择性压力,喂养,繁殖以及捕食者-猎物和同种相互作用。人类活动引起的土地利用变化改变了这些选择压力,并可能导致生物体的适应。两栖动物是异温动物,通常表现出具有水生和陆生阶段的双相生命周期,这使得它们对环境变化特别敏感。我们研究了四种类型的栖息地对法兰西岛地区palmatenew种群的影响:城市,混合,农业,和自然,每种栖息地类型至少重复两次。我们用卡尺测量了new的形态,使用高速视频记录量化最大跑步和游泳速度和加速度,并量化与炎症反应有关的后肢肿胀。我们的结果表明,在城市栖息地,new更大,更重,身体状况更好。雌性,此外,在自然栖息地有一个更大的头,可能是由于繁殖季节雌性的饮食专业化。在混合和农业栖息地,new的四肢较长,表现出跑得更快的趋势,可能与混合生境中运动的选择性压力有关。在性别之间观察到炎症反应的差异,而不是栖息地类型。总的来说,我们的结果表明,在不同的栖息地中生活的new的形态和性能差异的趋势表明,动物正在适应人类引起的环境变化。