Temperatures get warmer, bushes sprout buds and lawns gradually turn green. It’s springtime. Have you also noticed how, with each passing day, some songbirds appear to become more colourful? Goldfinches, for example, transform their dull winter plumage into electric hues of yellow. Similar changes occur in other species such as the Scarlet Tanager, Cardinals, and Indigo Buntings. Why this sudden burst of colour?
Springtime is mating time, so male songbirds want to look their best. Their colourful feathers make them more attractive to females. Bright colours indicate that a male is healthy and a potentially good provider for future offspring. As hours of daylight increase during spring, photoreceptors are triggered in songbirds, causing various changes. Photoperiodism is one process that takes place. This encourages the development of the bird's sexual organs and the production of sexual hormones.
Vibrant colours also help clearly define a particular species, preventing any hybridization (inter-breeding of species). According to Birdwatching magazine, “Bright colors, especially reds, oranges, and yellows, make males more visible to rivals and this allows them to effectively show their presence and ownership of a territory.”
As you watch the world wake from its long winter’s sleep, keep an eye on those songbirds – they’re nature’s early adaptors.
