Dodo birds went extinct because they trusted humans too much. they were very social, and humans hunted and ate them.
Endemic to Mauritius, when Dutch sailors arrived in the late 1500s, the dodos would calmly approach people out of curiosity, making them very easy to hunt. Humans did hunt and eat them (they were a convenient source of fresh meat for sailors), and the birds were described as social and curious.
Their exctintion was accelerated by invasive species that humans accidentally (or intentionally) brought with them: rats, pigs, cats, dogs, and monkeys that ate dodo eggs and chicks (dodos nested on the ground).
The last confirmed sighting of a dodo was around the 1660s, less than 100 years after humans first arrived. Their slow reproduction (only one egg per year) made recovery impossible.