The weaning period for gray whale (Eschrichtius robustus) calves is important for maternal instruction and learning. We examined observational and acoustic data from a foraging site for evidence of calf development and mother‐young information transfer. Site survey data demonstrated an initial prioritization of calf protection by using shallow shoreline areas. Foraging in more open water was only noted in late summer, perhaps an indicator of the maturation of the calf. Other indicators of development were found in acoustic recordings made over two summers. Motherese call types have been reported from recordings made in breeding lagoons, but have not before been described outside of calving regions. They were present in recordings from this study site, predominantly in the early summer and not heard past late July. We suggest vocal repertoire may evolve as the calf ages, and more adult calling behaviors eventually replace motherese. Long‐term mark‐recapture analyses demonstrated a high return of calves to the area to forage in summers subsequent to weaning, suggesting maternally inherited prey preference and site use behaviors. From our findings we suggest a calf's first summer is a highly critical period for development and may be formative in shaping future behaviors and habitat use patterns.

中文翻译：

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灰鲸在夏季觅食地的母性行为

灰鲸的断奶期（Eschrichtiusrobustus犊牛对于产妇的指导和学习很重要。我们检查了觅食地点的观测和声学数据，以发现小牛发育和年轻母亲信息传递的证据。现场调查数据表明，通过使用浅岸线区域，小牛保护得到了最初的优先考虑。仅在夏末才在更开放的水中觅食，这可能是小牛成熟的指示。在两个夏天制作的录音中还发现了其他发展指标。从繁殖泻湖的记录中已经报道了母性的呼唤类型，但是在产犊区域之外从未有过描述。他们出现在该研究站点的录音中，主要出现在初夏，直到7月下旬才听到。我们建议声乐曲目可能会随着小腿年龄的增长而发展，并且更多的成人呼叫行为最终取代了母语。长期的标记捕获分析表明，在断奶后的夏季，犊牛大量返回该草场，这表明母体继承了猎物的偏爱和站点使用行为。根据我们的发现，我们认为小牛的第一个夏天是发育的关键时期，可能会影响未来的行为和栖息地使用方式。