What drastic change occurred in the dodos living conditions in 1507?

The Portuguese sailors hunted and killed them for meat. Since the birds were flightless and fearless and did not make any attempts to flee, the sailors slaughtered them in large numbers.

In 1507 Portuguese sailors first started visiting the island of Mauritius, home to the dodo bird. While the dodo did not go extinct until the late 17th century, in 1507 it would have had it's first encounters with humans and the earliest record of the bird's existence in western civilization. While on the island the Portuguese would have learned that the dodo was both fearless of humans and unable to fly, making it an extremely easy prey. Although the Portuguese only stayed on the island for about 10 years, the Dutch took control of Mauritius in 1598 and just as the Portuguese did, hunt down the dodo until it became extinct.