Modifiers matching warbler:

• common,
• migrant,
• breeding,

Simple categories matching migrant:

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