Picture yourself as a bird. A chickadee. Proud parent of half a dozen nestlings. You have a territory - an area with a radius of about 50 metres that you defend from others of your species to get first dibs on resources. You have a job - to work with your mate to get food to your chicks. It’s a challenge.
Many may think of you as a seed and berry eater. But for chickadee nestlings, seeds are of no interest. These youngsters need protein! And that comes from insects. Ninety-six per cent of terrestrial birds rear their young on insects. The best source of protein is caterpillars - the larvae of moths, butterflies and sawflies.
Back and forth, back and forth. You and your mate work from dawn to dusk to satisfy the chicks’ voracious appetite. How much do they eat? Doug Tallamy, professor of Entomology and Wildlife Ecology at the University of Delaware, parked himself by a chickadee nest and counted.
He found the pair delivered food every three minutes. Once, they delivered 30 caterpillars in 27 minutes. They foraged from 6 am to 8 pm. He figured they delivered 390-570 caterpillars a day. The chicks spent 16-18 days in the nest. Just getting the young to a point where they can leave the nest takes 6,240-9,120 caterpillars!