Hadeda Ibis: The Camper’s Alarm Clock

Hadeda Ibis (Bostrychia hagedash) is a common sight and sound at South African campsites.

Known for their loud, distinctive “haa-haa-haa-de-dah” call, these birds are often heard before they are seen. Ask any long-term or holiday camper what their most frustrating camping sound is, and the call of the Hadeda is usually in the top three!

They are often called “Africa’s alarm clock” and campers are all too familiar with their early-morning and sunset calls.

Hadeda Communication: The Meaning Behind the “Haa-dee-daa” Sounds

The loud and resonant “haa-dee-daa” call is a hallmark of this bird, especially in South African campsites where it is a familiar sound in many urban and rural areas.

Understanding the communication patterns of Hadeda Ibises provides insight into their behaviour, social interactions, and environmental adaptations.

The “Haa-dee-daa” Call

The “haa-dee-daa” call is the most iconic sound associated with the Hadeda Ibis, and often the sound that frustrates long-term and holiday campers who would like to sleep a bit later.

This call is typically loud, carrying over long distances, and is often heard in the early morning or late afternoon.

The vocalization consists of three distinct syllables: “haa,” “dee,” and “daa.”

The reasons behind this specific call include:

Territorial Announcements: One primary function of the “haa-dee-daa” call is to establish and defend territory. By vocalizing loudly, Hadeda Ibises signal to other birds that a particular area is occupied. This helps to reduce conflicts over feeding and nesting sites.
Mating Calls: During the breeding season, the “haa-dee-daa” call can serve as a mating call. Males and females use these calls to attract mates and to communicate readiness for breeding. The loud and repetitive nature of the call ensures it can be heard over large areas, increasing the chances of attracting a partner.
Alarm Calls: Hadeda Ibises also use the “haa-dee-daa” call as an alarm signal. When they perceive a threat, such as a predator or human disturbance, they will call out loudly to alert other members of their group. This collective alert system helps to protect the flock by ensuring all birds are aware of potential dangers.

Other Vocalizations

In addition to the characteristic “haa-dee-daa” call, Hadeda Ibises produce a variety of other sounds.

These include:

Grunts and Croaks: These sounds are often softer and used during close-range interactions. They can serve as communication between mates, especially during nesting and feeding activities. Grunts and croaks can indicate contentment or mild irritation.
Hisses: When threatened or cornered, Hadeda Ibises may hiss as a defensive mechanism. This sound, combined with physical displays such as fluffed feathers and spread wings, serves to intimidate potential predators or rivals.
Chattering: In social groups, particularly among young birds, chattering sounds can be heard. These are less structured than the “haa-dee-daa” call and are used in a variety of social contexts, including play and establishing social hierarchies.

Social Structure and Communication

Hadeda Ibises are generally social birds, often seen in small groups or pairs.

Their communication patterns reflect their social nature and are crucial for maintaining group cohesion.

Here are some key aspects of Hadeda social communication:

Pair Bonding: Hadeda Ibises form monogamous pairs, and vocal communication plays a vital role in maintaining these bonds. Pairs engage in mutual preening and vocal exchanges to reinforce their partnership.
Flock Dynamics: In urban areas, Hadeda Ibises may form larger flocks, especially around abundant food sources. Vocal communication helps coordinate movement and foraging activities within these flocks.
Parent-Offspring Communication: Parents and chicks engage in continuous vocal communication. Chicks use begging calls to solicit food from their parents, while parents use soft calls to reassure and guide their young.

Adaptation to Urban Environments

Hadeda Ibises have successfully adapted to urban environments, and their vocal behaviour reflects this adaptability.

In cities and towns, their loud calls are a familiar background noise, often heard over the sounds of human activity.

Urban areas provide abundant food sources and nesting sites, and the adaptability of Hadeda Ibises to these environments is a testament to their resilience and versatility.

Understanding the “Haa-dee-daa” Call of the Hadeda Ibis in Flight

This call, particularly when the bird is in flight, has intrigued both ornithologists and bird enthusiasts.

Flight Calls: An Overview

Flight calls are vocalizations that birds make while they are flying.

These calls can serve various functions, including maintaining contact with other birds, signaling distress, and coordinating group movements.

In the case of the Hadeda Ibis, the “haa-dee-daa” call heard during flight has several potential meanings and purposes.

Territorial and Social Communication

Territorial Announcements:

Establishing Presence: When Hadeda Ibises take to the air, their loud “haa-dee-daa” calls can serve to announce their presence. This is particularly important for establishing and maintaining territorial boundaries. By calling during flight, Hadeda Ibises signal to other birds that the area is occupied and defended.
Deterrence: The loud call can deter potential intruders from entering their territory, reducing the likelihood of conflict over resources such as food and nesting sites.

Social Cohesion:

Maintaining Contact: In social groups, particularly during flock movements, the “haa-dee-daa” call helps individuals maintain contact with each other. This is essential for coordinating group movements and ensuring that no bird gets separated from the flock.
Reinforcing Bonds: For mated pairs or family groups, calling during flight can reinforce social bonds and ensure that the birds remain together as they move between feeding or roosting sites.

Alarm and Distress Signals

Predator Awareness:

Alerting Flock Members: When Hadeda Ibises detect a predator, either on the ground or in the air, they may take flight and call out loudly. The “haa-dee-daa” call in this context serves as an alarm signal, alerting other birds to the presence of danger. This collective alarm response helps protect the flock by increasing vigilance and reducing the chances of predation.
Startling Predators: The sudden, loud call can also startle potential predators, giving the Hadeda Ibis a better chance to escape.

Human Disturbance:

Reacting to Humans: In urban areas, Hadeda Ibises often encounter humans and may be disturbed by sudden movements or noises. When taking flight in response to human activity, their calls can signal distress and prompt other birds to take caution.

Navigational and Environmental Factors

Navigational Cues:

Orientation: Vocalizing during flight can help Hadeda Ibises orient themselves and communicate their flight path to other birds. This is particularly useful during migration or when moving between distant feeding sites.
Environmental Awareness: The call may also serve to assess the environment, with birds listening for echoes or responses that help them navigate through complex landscapes, including urban environments.

Weather and Time of Day:

Weather Conditions: Flight calls may vary depending on weather conditions. For example, birds might call more frequently in foggy or rainy conditions to maintain contact and ensure safe navigation.
Daily Routines: The “haa-dee-daa” call is often heard at specific times of day, such as early morning or late afternoon. These calls may be part of daily routines, signaling movements to and from roosting sites.

Habitat and Distribution

Hadeda Ibises are widely distributed across sub-Saharan Africa.

In South Africa, they are particularly abundant in urban areas, parks, gardens, and wetlands.

These birds are highly adaptable and can thrive in various environments, including rural and suburban settings. Their ability to coexist with humans has made them a common feature in many South African towns and cities.

Physical Characteristics

Hadeda Ibises are large birds, with an average length of about 76 centimeters and a wingspan of up to 95 centimeters.

They have a predominantly grey-brown plumage, with iridescent green or purple patches on their wings. Their long, curved bill is adapted for probing into the soil, a key feature that aids in their foraging.

Unique Foraging Behaviour

One of the most intriguing aspects of the Hadeda Ibis is its unique foraging behaviour which is why researchers called it the bird with the sixth sense.

These birds have a highly developed sense of touch, allowing them to detect prey in soil, and the research found that they sense vibrations even better in wet soil.

Studies have shown that Hadeda Ibises possess a specialized sensory organ at the tip of their bill, known as the “Herbst corpuscle.” This organ helps them sense vibrations and movements of hidden prey, such as insects and earthworms, especially in wet conditions.

Wet soil amplifies the vibrations and movements of their prey, making it easier for Hadeda Ibises to locate their food.

This sixth sense is less effective in dry soil, which is why these birds are often seen foraging after rain or in irrigated areas. Their ability to sense prey underground gives them a significant advantage and explains their success in various habitats.

Diet

Hadeda Ibises have a varied diet that includes insects, earthworms, snails, and small vertebrates.

They are also known to eat human food scraps, particularly in urban areas.

Their foraging method involves probing the soil with their long bills to extract prey. This diet makes them valuable for pest control, as they help keep insect and snail populations in check.

Breeding and Nesting

Hadeda Ibises are monogamous and typically breed during the rainy season when food is abundant.

They build large, untidy nests in trees, using sticks and other plant materials. Both parents are involved in incubating the eggs and feeding the chicks.

The chicks fledge about six weeks after hatching but continue to rely on their parents for food for several more weeks.

Role in the Ecosystem

Hadeda Ibises play a crucial role in the ecosystem.

By controlling insect and snail populations, they help maintain a balance in their environment.

Their presence in urban areas is particularly beneficial, as they can reduce the number of pests in gardens and parks. Additionally, their foraging behaviour aerates the soil, promoting healthier plant growth.

Human Interaction and Cultural Significance

In South Africa, the Hadeda Ibis is both loved and loathed.

While some people appreciate their pest control services and their role in the ecosystem, others find their loud calls annoying, especially in the early morning. Despite this, the Hadeda Ibis has become a familiar and iconic bird in South African culture.

Their loud calls are often associated with the coming of rain, and in some local traditions, they are considered messengers of the rain gods.

Their adaptability and resilience have made them a symbol of survival and adaptability in a rapidly changing environment.

Conservation Status

Hadeda Ibises are currently not considered threatened and have a stable population across their range.

Their ability to adapt to urban environments has helped them thrive despite habitat loss in other areas. Conservation efforts for these birds primarily focus on protecting their natural habitats and ensuring the availability of foraging grounds.

Conclusion

Despite their loud calls, these birds are an essential part of South Africa’s natural heritage and cultural landscape.

The loud and distinctive calls of these birds remain a defining feature of South African soundscapes, symbolizing the dynamic interactions between wildlife and human-dominated landscapes.

Campers will have to live with Africa’s alarm clock as long as camping exists because where we camp is where the Hadeda lives.