As an expert in bird behavior, I can provide a detailed answer to the question of why Hadidas scream when they fly. It is important to note that the behavior of Hadidas, also known as African Sacred Ibises, is complex and can be influenced by various factors. While there is no definitive answer, several hypotheses have been proposed to explain this behavior.
One hypothesis suggests that Hadidas scream when they fly due to a fear of heights, similar to acrophobia in humans. This theory suggests that the birds experience anxiety or discomfort when flying at higher altitudes, leading them to vocalize their distress. This could explain why the calls of Hadidas are often heard when they are in flight. However, it is important to note that this hypothesis is speculative and has not been scientifically proven.
Another possibility is that the screams of Hadidas serve as a form of communication or social interaction. Birds, in general, use vocalizations to communicate with each other, and the calls of Hadidas could serve as a way to maintain contact with their flock members during flight. It is also possible that the loud calls help to deter potential predators or competitors, as a means of asserting their presence or defending their territory.
Additionally, the screaming behavior of Hadidas could be influenced by environmental factors such as stress or disturbance. For example, if a Hadida feels threatened or startled during flight, it may emit loud calls as a way to alert other members of its group or to warn potential predators. Similarly, if the birds encounter unfamiliar or challenging situations while flying, they may vocalize their discomfort or confusion.
Personal experiences and observations can also provide insights into this behavior. Many people, including myself, have witnessed Hadidas screaming while flying in groups. These calls are often described as loud and distinctive, resembling a harsh and repetitive “haa-de-daa” sound, hence their common name. The calls are typically heard during the early morning and late afternoon when the birds are most active.
The reason why Hadidas scream when they fly is still not fully understood. While there are hypotheses suggesting a fear of heights or a form of communication, further research is needed to provide a definitive answer. It is likely that a combination of factors, including fear, communication, and environmental influences, contribute to this behavior. Understanding the behavior of Hadidas and other bird species requires careful observation and scientific investigation.