Birds of paradise
The King of Saxony is one of 38 amazing bird of paradise species in Papua New Guinea that attracts a mate with a curious dance and feather display.
Find out why the spectacular King of Saxony stands out among Papua New Guinea’s birds of paradise
The climb up 300m had taken over an hour and three tumbles. By the time we arrived at the top of the ridge, we were covered in mud and panting heavily. Well, most of us were. Our guide, Joseph Tono, who ended up carrying a lot of our gear to save it from crashing onto the forest floor when we slipped, was mud-free and breathing normally.
Early that morning, our journey had started from a lodge situated 2,130m up in the Highlands of Papua New Guinea. We were now at 2,430m and appreciating how thin the air is at that height. Joseph’s acclimatised lungs were probably 25 per cent bigger than ours, and he was definitely more sure-footed on the sodden track.
Once at the top of Rondon Ridge, we began to scan the treetops for birds of paradise – or BoPs as they are affectionately known – which live at these lofty heights. I particularly wanted a look at a King of Saxony, and Joseph had said our chances were good, if the low cloud and rain let up.
Trails of mist drifted through the trees, giving the montane forest an eerie feel. The waterlogged air distorted the calls of unseen birds that Joseph nevertheless identified as black sicklebill, white-winged robin and bartailed cuckoo-dove. After an hour, the sun gradually began to drive away the cloud and the forest emerged in all its glistening glory. Now we could see a particular bare branch that Joseph said was a favourite perching post of a King of Saxony. Sure enough, he picked out the distinctive call amongst the ambient bird sound, and the show was on.
Song and dance
My curiosity with a bird that some might consider one of the least colourful of the 38 species of BoPs in New Guinea, began when I saw a YouTube video of a male’s courtship display. It was made by the Cornell Lab of Ornithology, part of Cornell University in New York state, which has been conducting a long-term bird-of-paradise project. The film showed a crow-sized bird, at the top of a dead branch, with a bright yellow breast and two extremely long, thin ‘feathers’ rising from behind its eyes. Its call was a raspy, squeaky, whistling sound delivered with beak wide open, showing a pale blueygreen interior. Having shouted from its perch, it dropped down onto a vine, where it bounced up and down, calling and fluffing its neck feathers into a ruff.
All very impressive, but it was those long feathers that I found most fascinating. They are anchored to the bird’s head in shallow depressions, and the power to move them around independently seems to be invested solely in the skin over the skull.
The plumes themselves are less like conventional feathers and more like rigid leaf-shapes – there are 30 to 40 of them attached to one side of a ‘stiff wire’.
Birds of paradise first came to widespread notice outside of ornithological circles when they featured in Lords of the Air, the eighth episode of David Attenborough’s Life on Earth series, first broadcast 40 years ago.
These documentaries established Attenborough’s international reputation as a television naturalist and introduced the British public to previously unseen wonders.
One of a kind
Attenborough was entranced by the exotic displays put on by male birds of paradise to attract the attention of a female. In an article in New Scientist, he declared, “Most extraordinary of all is the King of Saxony bird of paradise. His body is comparatively drab, but he grows two huge quills from the back of his head, each notched with blue enamel-like plates; there is nothing like them in the bird world.”
Coupled with these bizarre appendages – which bear little resemblance to the body adornments of even the showier birds of paradise – the King of Saxony is also
Having shouted from its perch, it dropped down onto a vine, calling and fluffing its neck into a ruff.
unique in its genus of Pteridophora.
Birds of paradise belong to a group of birds known as passerines, which comes from the Latin passer, meaning ‘sparrow’, therefore sparrow-like. Passerines make up more than half of all bird species as the term covers anything that perches. What most distinguishes them is their anisodactyl toes – three facing forwards and one back. These enable the bird to grip and, in addition to strengthened legs, the resting position of their feet is a clenched one, so they can maintain a hold even when asleep.
Food fight
Before our stay near the town of Mount Hagen and hike up to Rondon Ridge, we were staying at Kumul Lodge in Enga Province, where a fruit-stocked bird table provided an irresistible breakfast draw to a panoply of bird species. It was a gentle introduction to the wonders of birds of paradise. Though it could be said to be cheating, given the efforts needed to track down BoPs in the wild, it did have the advantage of allowing close and prolonged views of the birds and their behaviour.
A number of brown sicklebills came to the table – birds of paradise that have evolved the ability to peel open and penetrate the pods of capsular fruit. That’s not to say they pass up a meal of fruit that’s been cut open for them, of course. They’ve learned to use their curved beaks to excise a morsel of mango from its skin and toss it into the air, so they can catch and swallow it.
Ribbon-tailed astrapias also visited daily, the males somehow navigating a path through the trees without damaging their two magnificent white tail streamers. A juvenile ribbon-tail, whose tail feathers had not yet reached their full length, was pursued relentlessly by a mature adult determined to drive it away. His noisy and boisterous defence of his territory continually scattered the smoky honeyeaters, Brehm’s tiger parrot and Belford’s melidectes that were also attempting to enjoy the fruit buffet.
Colour combinations
The fact that New Guinea – now divided into Western New Guinea administered by Indonesia and the independent state of Papua New Guinea – is an island group with an agreeable climate and dense forests abundantly blessed with fruiting trees, is one of the secrets why birds of paradise evolved there almost exclusively. Only in the most north-easterly tip of Australia can you
Males know what they need to do to acquire a mate, and will practise their calls and dances.
find any other BoP species – the paradise and Victoria’s riflebirds and the trumpet manucode. All three species are black with iridescent purple or green feathers; although arresting in their coloration, they have not evolved the variety of hues seen in species that live exclusively in New Guinea.
The Cornell Lab’s project (which includes the Australian species) explains the reasons behind fantastic feather forms. The theory of evolution by natural selection, as described by naturalist Alfred Russel Wallace in 1858, explains how physical traits that advantage foraging or survival against predators occur by chance mutations passed on in the genes of the successful animals.
Though Wallace did not coin the term ‘natural selection’ he did describe how species evolve through environmental pressures that favour one characteristic over another. So, one branch of a family could develop in quite a different way to another simply because of local living conditions. His work on this dovetailed with Charles Darwin’s, and the 1858 paper explaining evolution was jointly published.
The problem with birds of paradise, and the quirky appearance and behaviour of the males fitting into the model of natural selection, is that the extreme feather modifications and elaborate courtship dances benefit neither foraging nor eluding predators. Complex plumage can hinder progress in dense forest and aid detection by other species – good reasons not to develop in such an extravagant way.
Ladies’ choice
This is where Darwin’s assertions that the competition within members of the same species to mate and pass on their genes also influences evolution, in this case by sexual selection on the part of the females.
This has come to be accepted as a logical hypothesis, although there is still a question mark over exactly what dictates the female birds’ choices of mate. Are they picking elaborately plumed males simply because they are visually attractive and dance well, or is it that these things indicate strength, and a likelihood that the coupling will produce youngsters robust enough to survive?
Whatever the reasons, the males know what they need to do to acquire a mate, and will practise their calls and dances even when there are no females present. This was the case with our Rondon Ridge King of Saxony. We were outside the breeding season and Joseph could not detect a female anywhere in the vicinity, but the male we were watching still went through his paces.
Theories of sexual selection may explain why these birds have developed with such seemingly useless coats of many colours and peculiar choreography, but why did they evolve in such different ways? This aspect speaks to the lushness of New Guinea, its geographical features and its isolation. A vast acreage of impenetrable rainforest and montane habitat, plentiful water and a rich, biodiverse plantlife provides an abundance of food and places to live.
The king of Saxony’s favoured dwelling place is the cloud forests of the central spine of Papua New Guinea. There, safe from predators, apart from the occasional human, it is free to assume its post, wave its flags and bounce its way to producing the next generation of birds that will delight anyone who climbs high enough to see them.
SHEENA HARVEY is BBC Wildlife’s Editor. Her trip was organised by Reef & Rainforest courtesy of Papua New Guinea Tourism Promotion Authority.
FIND OUT MORE The Cornell Lab BoP project: birdsofparadiseproject.org