Tallbirds are always asleep in the caves while outside of combat

As title says, whenever tallbird in the caves is not fighting something, it falls asleep immediately, which makes it impossible to get tall bird nest in the caves and - potentially - tallbird's egg farm. Tallbird doesn't react to light sources or sources of natural light (natural cave lights, dwarf stars). This is inconsistent with both behaviour of smallbirds and teenbirds in the caves and with behaviour of other creatures/natural objects: pigs and bees react to light source and come out of their spawners as long as it's day globally and there is light in the area; spiders (including dangling debth dwellers) come out of dens and return to them according to global day-night cycle; crops grow and lord of fruit flies spawns as long as there is source of natural light; flowers don't wither as long as there is source of natural light; beefalos are asleep only when it's night globally (otherwise they are awake even in complete darkness), mushrooms react to day-night cycle like on surface even in complete darkness, etc. I don't see why tallbirds should be different.