Modifiers matching labourer:

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

Simple categories matching migrant:

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