The world: sky nomads in solar-powered airships, roaming planet earth
The technology level: 2030s or 2040s. The airships are similar to the IRL designs LCAT60T airship by Flying Whales, Airlander 10, and Aeroscraft made by Worldwide Aeros Corp.
The question: how do they acquire food in the sky?
You may be thinking: couldn't they just land and get terrestrial/aquatic food? Yes, they can and they do. But they're sky-folk. They love the sky. They wear feathered garb. They should eat the sky too – fish the sky so to speak. It's an æsthetic thing. Ground-dwelling birds like bustards are less suitable than high-flying birds like swans for that reason.
Now these nomads are planet-wide, so they can go to different regions, following bird migrations and flocking/nesting events. (There's an old anthropology joke: 'nomad' is a word that means 'follow the meat'.)
One way to catch them would be a net extended below the ship, similar to a fishing trawler. The airships are faster than most birds and could scoop em up. But maybe there's a more interesting technique to trap em or hook em.
Aaaand, possibly a dumb question: what about the plant component of the diet? There are no plants in the air, are there? Or does the sky have some equivalent of phytoplankton? Maybe they could gather some wind-borne pollen or seeds; do any credible food-sources of that kind exist?