Modifiers matching visa:

• migrant,
• resident,
• temporary,
• permanent,
• valid,

Simple categories matching migrant:

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