The grey-crested helmet-shrike is a highly social species, living in permanent groups of up to 12 to 17 individuals (2) (5). Groups defend territories and are co-operative breeders, with all members of the group, including juveniles, helping to build the nest, incubate the eggs, and brood and feed the young. Nesting usually takes place between April and May, the cup-shaped nest being built in dense vegetation, which may help to conceal it (2) (5) (6). The framework of the nest is typically built from tree bark, and the cup is lined and plastered to a smooth finish with cobwebs, which are also used to bind the nest to the branch. Three to four eggs are usually laid, though more than one clutch may be laid in the same nest, and all group members help with incubation, which lasts for 16 to 18 days (6) (7). Nesting success is thought to be low due to nest predation (5) (6), but re-nesting may occur when a clutch is lost, the group moving to a new tree to build a new nest some distance away (6) (7).
Little other information is available on the ecology of the grey-crested helmet-shrike, but, like other helmet-shrikes, it is likely to feed on insects (4), including insect larvae, grasshoppers and praying mantises (6).