The diet of the lesser noddy consists mainly of small fish and squid (2) (3) (5) (6), and this species hunts by flying low over the sea before hovering and dipping down to pick prey from the surface of the water (2) (3) (4). Before breeding, adult lesser noddies also eat large quantities of coral fragments from beaches, presumably as a source of calcium for producing eggs (6).
The lesser noddy usually breeds between August and October (2), often coming together in large breeding colonies in which nests are densely packed together (2) (5). In some areas, egg laying may continue into early December, or even extend to the following April (3) (5) (8). The nest of the lesser noddy is built in a tall mangrove tree, or occasionally in a bush, and consists of a bulky platform of seaweed held together with excrement (2) (3) (5). Storms can sometimes cause extensive loss of eggs from more exposed nests, and pairs nesting earlier in the season tend to select more sheltered sites (8). Nesting colonies of lesser noddies periodically move location as the nesting birds retard tree growth and can even kill the trees (3) (7).
The female lesser noddy lays a single egg (2) (3) (8), which is incubated for about 34 to 35 days (2) (8). The young lesser noddy fledges at about 40 days old (8), and individuals are likely to start breeding from about 3 to 4 years old (3) (7).
Outside of the breeding season, the lesser noddy remains gregarious, occurring in flocks of up to about 45 individuals and often associating with brown noddies (A. stolidus) (6).