The majority are attracted by the numerous broad river estuaries and rich tidal marshes and mud-flats along Taiwan's west coast, so there are far fewer migrant birds, and of fewer species, on the steeper eastern coast.
台灣西部海岸有許多開闊的河口，潮汐造成的肥沃沼澤、泥灘，吸引了大多數的候鳥；花東沿岸候鳥的鳥數、鳥種因此大不如西岸。