Modifiers matching labourer:

• unskilled,
• casual,
• migrant,
• skilled,

Simple categories matching migrant:

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