Rock Pigeon - 自然英语

Birdslay eggs. That means they don’t nurse their young… right? Well, have you everheard of something called “pigeon milk?”Pigeons,one of the most ancient of domesticated birds, feed their nestlings a peculiar,milky liquid- straight from the adult’s beak to the baby’s throat.It’soften called “crop milk,” because it comes from special cells in the birds’crop. The crop is a section of the lower esophagus in some birds that is usedfor storing food before digestion.<p style="color:#33333...