The glossy ibis (Plegadis falcinellus) is a wading bird species that can be found across much of the world. Known for its distinctive curved bill and iridescent plumage, the glossy ibis is a remarkable bird that is highly identifiable by both its appearance and its vocalizations.
In this article, we will explore the various calls and sounds that the glossy ibis makes, providing audio examples so you can hear its vocalizations for yourself. We will cover the contexts in which the different calls are made and what they communicate. Understanding what a glossy ibis sounds like can help birdwatchers more readily identify this species in the field.
An Overview of Glossy Ibis Vocalizations
The glossy ibis has a diverse repertoire of sounds it uses to communicate different messages. Here is a quick overview of some of the main glossy ibis vocalizations:
- Croaking and grunting noises made during breeding displays
- Nasal, drawn-out honking sounds in flight
- Harsh, rattling calls when disturbed
- Chattering sounds during feeding
- High-pitched squeaking noises between mates and young
The glossy ibis combines these vocalizations along with visual displays like head-bobbing and wing-spreading to convey different meanings. Context is key to understanding what the ibis is communicating when it makes sound. Next, we will explore some specific glossy ibis calls in more detail.
Breeding Displays and Sounds
The breeding season elicits some of the most remarkable vocalizations from the glossy ibis. These sounds are associated with courtship rituals and pair formation.
Male glossy ibises make low, croaking rattles and grunting noises to attract females and establish territories. Here is an example of these breeding vocalizations:
As the recording demonstrates, the croaking and grunting sounds are deep and carry over distance. This helps the male ibises declare their territory and attract mates in dense marsh breeding habitat. The bill-clattering accompanies visual displays like head-bobbing, wings-spread, and bill-up postures.
Females may respond with higher-pitched versions of the rattling and grunting sounds. Mated pairs also make noises like short trumpeting calls during courtship feeding rituals and copulation. These varied sounds help facilitate pair bonding.
Flight Calls
The sounds glossy ibises make while in flight also help birders identify them. The flight call is a distinct nasally, honking sound that gets drawn out over duration. It can sound like a short “nyah” or a more drawn-out “nyaoooow.”
Here is an audio clip of the flight call:
This far-carrying call is thought to help keep flocks coordinated over distances and maintain group cohesion. The flight call is one of the best ways to detect glossy ibises as they pass overhead, even if they are out of visual range. It’s a good signal to birders that ibises are migrating through the area.
Alarm and Distress Calls
When disturbed or attacking threats, the glossy ibis makes harsh, rattling calls. These alarm or distress calls sound hurried and grating, with a strong rasping tone.
Here is an example:
The ibises make these calls to signal danger to others in their flock. The harsh sounds carry urgency to alert other birds to retreat or be vigilant. A glossy ibis may also make these rattling sounds when attacking or mobbing predators that get too close to their nest. The calls recruit other ibises to join in driving the threat away.
Feeding Chatter
Glossy ibises often forage together in flocks. While feeding in shallow water, they make social chattering sounds amongst one another. These vocalizations likely help maintain contact and coordination as the flock scours for prey.
The feeding chatter consists of subdued croaking, clattering, and grunting sounds. Here’s a recording:
This background chatter is a sign that there is a group of feeding ibises nearby. It provides context that the ibises feel relatively safe and are going about their regular business. The feeding chatter may intensify if good sources of prey are discovered.
Sounds Made by Chicks
During the breeding season, the sounds of chirping chicks can be heard at glossy ibis nesting colonies. The chicks make high-pitched squeaking and peeping sounds. This helps them beg for food from their parents.
Listen to some examples of ibis chick vocalizations:
The adult ibises respond with soft clucking and crooning sounds to soothe and communicate with their young. These gentle sounds are very different from the harsher calls. Learning to distinguish ibis chick sounds can help observers locate active nesting colonies.
Regional Differences
While the core sounds are similar, there are some subtle regional dialects between glossy ibis populations. Ibises from different parts of the world may have slightly different accents and tendencies in their vocalizations. These distinctions are not easily discernible to casual observers.
However, scientists who study ibises can analyze sound recordings and measure slight variations in the pitch, tone, and frequency of calls between populations. The regional vocal differences likely arise over generations due to isolation and adaptation to local habitat conditions. Nonetheless, the general sound profile remains consistent across glossy ibis subspecies.
When Are They Most Vocal?
Glossy ibises engage in more vocalizations during certain times of day and year. In general, ibises are most vocal early and late in the day, especially around dawn and dusk. The low light conditions mean they rely more on sound to maintain flock contact.
The breeding season is also a peak time for vocalizations associated with courtship, pairing, and defending nest sites. Outside of breeding, glossy ibises are mostly quiet while roosting but chatter while active and foraging. Migratory populations vocalize more frequently as they travel between nesting and wintering grounds.
So dawn or dusk during spring migration provide the greatest chances to hear glossy ibis vocalizations. Knowing when they are most vocal can help birders plan productive times to listen for identifying sounds.
Conclusion
In summary, the glossy ibis has a wide array of sounds it uses to facilitate breeding, maintain flock cohesion, communicate alarm, and socialize. Croaking and grunting prevail during courtship displays. Drawn-out honking characterizes flight calls. Alarm calls are harsh and rattling. Feeding groups chatter, while chicks squeak and peep. Regional dialects create some variation. Dawn and dusk, plus the spring breeding season, are when ibises are most vocal and readily detected.
Now that you know the diverse sounds produced by the glossy ibis, you can listen for them in wetlands where ibises occur. Identifying the unique vocalizations will help birdwatchers distinguish this iconic wetland species by ear during field observations. With a little practice, you’ll be able to confidently pick up on the characteristic sounds of the glossy ibis.