Marabou storks nest in large colonies that consist of 20 to 60 pairs but may number in the thousands. They will return to the same colony and nest site every year for mating. Males will arrive first to establish territory, inflating their gular sacs and greeting all visitors with equal hostility. Females will respond passively and when accepted as a mate, will inflate their own sacs and repel intruders as well. Although the same nest can be used over again, extensive rebuilding is required.
Unlike most storks, the Marabou flies with its neck retracted, like a heron. But like most storks, the Marabous are a gregarious bird. They are not very vocal but will indulge in bill-rattling during courtship displays. The throat sacs are inflated and used to make some noises at that time.
The marabou stork’s legs and feet are dark grey, but the build up of excrement makes them appear almost white and is thought to aid in thermoregulation