Modifiers matching visa:

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

Simple categories matching migrant:

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