Modifiers matching labourer:

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

Simple categories matching migrant:

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