The glossy ibis is a ‘tactile forager’, locating prey items by touch as it probes the substrate with its long, curved bill (4) (6). Touch sensors on the bill allow the bird to rapidly snap it closed when it encounters prey, while ridges along the bill ensure that prey is grasped firmly in place. After catching its prey, the glossy ibis lunges the head forward to send the prey item closer to the mouth, sometimes biting it several times before it is swallowed, or else allowing it to pass straight down the gullet whole (6). The glossy ibis has a broad diet, which varies seasonally (5) (6). It generally feeds on the adults and larvae of various insects, as well as molluscs and crustaceans, but small vertebrates, such as fish, frogs, lizards and small snakes, are sometimes also taken when encountered (2). Plant material, such as cultivated rice and sorghum, may also supplement the diet in some areas (4) (6). The glossy ibis typically forages in small flocks (2), and will roost communally, often in trees located far from its wetland feeding sites (5).
Throughout most of its range the glossy ibis breeds colonially, in large, mixed-species aggregations which often number thousands of birds. The breeding season runs between March and May (October to February in Australia), or coincides with the rainy season, depending on the location (2) (5). Both the male and female help to construct the nest, which is typically a compact platform of twigs or reeds, lined with leaves and other soft vegetation. It is often built over or close to water, usually less than one metreoff the ground, although occasionally up to seven metres (2) (4) (5). The female lays 3 to 4 eggs, which are incubated by both the male and female glossy ibis for a period of 20 to 23 days, with the female carrying out the greater share (2) (4). The chicks are able to leave the nest after 8 days, although they do not fledge (take their first flight) until around 25 to 28 days after hatching (2) (4). Both the male and female actively feed the chicks in and around the nest site for around six to seven weeks before they become fully independent (4).
The glossy ibis is a migratory and nomadic wading bird, with adults and young birds dispersing in all directions following breeding, often in separate flocks (2) (4) (5) (6). In northern populations, the glossy ibis wanders widely, before migrating southwards to its wintering grounds (2) (4).