PDF(Pubmed)
Abstract：
Understanding the ontogeny of diving behaviour in marine megafauna is crucial owing to its influence on foraging success, energy budgets, and mortality. We compared the ontogeny of diving behaviour in two closely related species-northern elephant seals (Mirounga angustirostris, n = 4) and southern elephant seals (Mirounga leonina, n = 9)-to shed light on the ecological processes underlying migration. Although both species have similar sizes and behaviours as adults, we discovered that juvenile northern elephant seals have superior diving development, reaching 260 m diving depth in just 30 days, while southern elephant seals require 160 days. Similarly, northern elephant seals achieve dive durations of approximately 11 min on their first day of migration, while southern elephant seals take 125 days. The faster physiological maturation of northern elephant seals could be related to longer offspring dependency and post-weaning fast durations, allowing them to develop their endogenous oxygen stores. Comparison across both species suggests that weaned seal pups face a trade-off between leaving early with higher energy stores but poorer physiological abilities or leaving later with improved physiology but reduced fat stores. This trade-off might be influenced by their evolutionary history, which shapes their migration behaviours in changing environments over time.
摘要：
由于海洋大型动物对觅食成功的影响，了解潜水行为的个体发育至关重要。能源预算，和死亡率。我们比较了两个密切相关的物种-北象海豹（Miroungaangustirostris，n=4）和南象海豹（Miroungaleonina，n=9）-阐明了移民的生态过程。尽管这两个物种的大小和行为与成年相似，我们发现幼年北象海豹潜水发育优越，在短短30天内达到260米的潜水深度，而南象海豹需要160天。同样，北象海豹在迁徙的第一天实现了大约11分钟的潜水持续时间，而南象海豹需要125天。北象海豹的较快生理成熟可能与更长的后代依赖性和断奶后的快速持续时间有关，允许他们发展他们的内源性氧气储存。两种物种之间的比较表明，断奶的海豹幼崽面临着一种权衡，即早期离开较高的能量储存，但生理能力较差，或者后期离开改善的生理机能，但脂肪储存减少。这种权衡可能会受到他们进化史的影响，随着时间的推移，在不断变化的环境中塑造他们的迁移行为。
