Modifiers matching shorebird:

• migrant,
• smaller,
• coastal,
• migratory,
• small,
• larger,
• modern,
• marine,
• breeding,

Simple categories matching migrant:

• sandpiper,
• bird,
• shorebird,
• group,
• population,
• worker,
• language,
• songbird,
• insectivore,
• passerine,
• thrush,
• waterbird,
• sparrow,
• finch,
• fish,
• warbler,
• visa,
• labourer,
• organization,