Modifiers matching shorebird:

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

Simple categories matching migrant:

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