Data from: Prenatal cues of predation risk modulate the lasting effects of postnatal predator exposure in gull chicks.

Prenatal environmental cues can affect embryo development to produce suitable phenotypes that match the expected conditions after birth. In gulls, parental alarm calls during incubation affect postnatal antipredator behaviour, but how chicks integrate reliable prenatal and postnatal information and how this influences their development and viability remain unclear. In this study, we performed a match/mismatch experiment in which we manipulated acoustic cues of predator presence during embryonic development (adult alarm calls vs. colony noise) and simulated predator intrusions during nestling period (mink vs. rabbit decoy) in yellow-legged gulls (Larus michahellis). Our results show that embryonic exposure to predator cues alters the antipredator responses of chicks in early postnatal life as indicated by increased tonic immobility. Chicks exposed to adult alarm calls also displayed rapid crouching behaviour, but only in the absence of predators during the postnatal period. Chicks exposed to postnatal predator presence showed less frequent begging vocalizations. The chicks experiencing mismatched prenatal and postnatal cues of predator presence showed smaller skeletal size and greater genomic damage at fledging, compared to those developed in matched environments. Our results highlight the importance of the late embryonic stage in shaping phenotypic outcomes, with fitness consequences depending on alignment with the postnatal environment.

产前环境线索（prenatal environmental cues）可影响胚胎发育，产生与出生后预期环境相适配的适宜表型。在鸥类动物中，孵卵期亲代的报警鸣叫声会影响雏鸟产后的反捕食行为，但雏鸟如何整合可靠的产前与产后信息，以及该过程如何影响其发育与生存能力，目前仍不甚明确。本研究以黄腿鸥（Larus michahellis）为研究对象，开展了匹配/不匹配实验（match/mismatch experiment）：在胚胎发育阶段操控捕食者存在的声学线索，设置成鸟报警鸣叫声与集群噪音两组处理；并在雏鸟期模拟捕食者入侵，设置水貂与兔子诱饵两组处理。研究结果显示，胚胎阶段暴露于捕食者线索，会改变雏鸟产后早期的反捕食反应，具体表现为强直静止（tonic immobility）时长增加。暴露于成鸟报警鸣叫声的雏鸟，同样会表现出快速蹲伏行为，但仅在产后阶段无捕食者存在的情况下出现。暴露于产后捕食者存在环境的雏鸟，其乞食鸣叫声的发生频率更低。与在匹配环境中发育的雏鸟相比，经历产前与产后捕食者线索不匹配的雏鸟，在离巢时骨骼体型更小，基因组损伤程度更高。本研究结果凸显了胚胎发育晚期对表型塑造的重要性，其适合度后果（fitness consequences）取决于与产后环境的匹配一致性。