Rose Thorogood at work with her spectrometer on Tiritiri Matangi Island. Image: Alison Ballance
Baby birds display brightly coloured mouths as they beg food from their parents. Rose Thorogood, a PhD student at the University of Cambridge, is investigating how mouth colour varies within and between different species of birds in New Zealand. She carries out some of her field work on Tiritiri Matangi Island, and, pictured below, is a saddleback, or tieke, chick, showing off its vivid mouth colour (image: Alison Ballance).