Delibird debuted in Dues and Don'ts, under the ownership of a Rocket Scout. She claimed that she and the Delibird were trying to recruit new members for Team Rocket. When Jessie and James told her that they were Team Rocket members, she said that they weren't in the system. James pulled out his membership card, and the scout informed them that, because they hadn't paid any of their dues, they had been kicked out of Team Rocket. The scout then told them that if they defeated a Trainer, they would be allowed back in. Using Delibird, Team Rocket battled Ash, and despite the fact that he won, the scout allowed them to rejoin. However, she also informed them that her Delibird would be following them around to collect their dues that they had still not paid.
In Xatu the Future, right before a flood was about to take place, Team Rocket told Delibird that they would pay it back with all of the items from the town that was about to be flooded. After the flood, all of the items were buried under several feet of dirt, and Team Rocket attempted to dig them out. Delibird flew away, promising to come back.
Delibird was seen looking for Team Rocket around the Slowpoke Temple at the end of Enlighten Up!. Hiding from it meant that they had to take their punishment for trying to steal the temple's statue.
At the end of Can't Beat the Heat!, Delibird took all of the money Team Rocket had earned during the Silver Conference. This apparently completed their dues as Delibird did not go looking for Team Rocket in Hoenn.
Delibird is dedicated to its job, as shown by its relentless pursuit of Team Rocket during the original series, when it was after the money that they owed to the organization. It doesn't appear to care about the trio's well-being, as demonstrated in Grating Spaces!, when it found them hanging by a branch; instead of helping them out, it took back the Pokémon it had wrongly delivered before flying off. In The Thief That Keeps on Thieving!, Delibird was rather surprised that the trio had something to give it.