Evolution In The Birds of Paradise

Evolution, or natural selection, progresses along quite simple lines. As time progresses certain genetic traits prove to be beneficial to the species. As the creatures possessing advantageous qualities stand more chance of surviving, over time the entire species will grow to possess the same traits, and the process continues. Traits are evolutionarily judged based on a few categories, ability to forage and hunt, ability to attract a mate, and ability to escape danger.

The process can demonstrate surprisingly short-term results. An interesting case study took place in the Bahamas, each of twelve islands featuring identical species of the lizard Anolis sagrei. On six of the islands new, ground-based predator was introduced. Within six months, the lizards on the study islands had considerably longer legs than those on the control groups, developed to help them run faster to hiding places in trees. Another six months after that the lizards had chosen to stay in their safe, arboreal habitat, and their legs had become substantially shorter than the control group, better suited for gripping trunks and branches.

The birds of paradise evolved in conditions that were fairly unique. Mainly living on the island of New Guinea, they had no natural predators, and food was in abundance. Straight away, two of the main reasons species evolve are ruled out. With this natural context, they evolved mostly along a single route, increasing their chances of attracting a mate as much as physically possible.

In sexually dimorphic species, as most birds of paradise are, each gender possesses an externally visible difference of anatomy, traits often used to attract prospective mates. The evolutionary freedom the birds of paradise enjoyed resulted in 39 species of bird, spread over 15 genera, which have exaggerated their sexually dimorphic traits to a degree never before seen in nature.

The King of Saxony species features two antennae-esque feathers, each far longer than its own body, able to be controlled within a 180′ field of motion as part of their courtship dance. The jet black riflebird whips its head back and stretches its wings into an ovoid shape. A bright blue, almost neon breast shield is pulsated and shaken in a hypnotising manner to demonstrate sexual capability to females. Some of these unique species hang upside down from trees, spreading immense tail plumage like a flag towards the sky, and the twelve-wired bird twists and rubs its whisker-like tail shafts into the female’s face when attempting to attract her.

The birds of paradise are a unique treat for ornithologists, having enjoyed the freedom to progress down an evolutionary path shut off to most species, coping with more threat in their day to day lives. Recently, an ornithologist and photographer duo finished an eight year project, photographing, recording and documenting all 39 species, along with their unique sexual rituals.

It’s a bittersweet victory, though the majesty of these birds is now able to be fully understood, the veil of mystery behind on of the most intriguing species on the planet has been pulled away, and an equivalent may never be found.