bird black common curious javan Myna Noisy precocious widespread aggressive alert birds brown colorful colourful inquisitive mature mother myna birds mynah plumage roadside ruffled ruffled feathers street watchful yellow african biological-interaction broad-mouthed collagen creases eating endangered flat-mouthed folds food gray grazer grey heavy herbivore herbivorous hide horns keratin large mammal myna-birds placid powerful rhino rhinoceros skin snout square-lipped-rhinoceros strong symbiosis symbiotic threatened tough white-rhinoceros wide-lipped-rhinoceros wrinkled wrinkles