Since the position of the sunset changes with latitude and season, researchers think that these birds must be able to compensate for the changes by means of a biological clock that tells them the time of year, says Science
व हे घड्याळ त्यांना वर्षातल्या विशिष्ट काळाची सूचना देत असावे, ” असे साइन्स पत्रकात म्हटले आहे.