Red-capped cardinals are not actually cardinals, but are instead classified in the group called tanagers. They eat insects, seeds, berries, and fruit. They are usually in family groups or pairs. They forage on the ground and around water, looking for food.
They use dry grass and twigs to make a nest overhanging water. The nest is cup-shaped and around 10 cm wide. They lay 2 or 3 eggs at a time.