Why did the number of trumpeter swans decrease between 1600 and 1800?

The number of trumpeter swans decreased between 1600 and 1800 primarily due to habitat loss and overhunting. As European settlers expanded into North America, wetlands were drained or altered for agriculture and development, reducing available nesting and feeding areas. Additionally, swans were hunted for their feathers and meat, contributing to their population decline. These factors combined led to significant reductions in their numbers during that period.