Every Christmas Harry receives a mediocre gift from the Dursleys. In Harry Potter and the Chamber of Secrets he gets a toothpick.

At that moment, Hedwig swooped into the room, carrying a very small package in her beak. “Hello,” said Harry happily as she landed on his bed. “Are you speaking to me again?” She nibbled his ear in an affectionate sort of way, which was a far better present than the one that she had brought him, which turned out to be from the Dursleys. They had sent Harry a toothpick and a note telling him to find out whether he’d be able to stay at Hogwarts for the summer vacation, too.

They hate owls, but obviously use them to contact Harry at school?