The amazing mating display of the marvellous spatuletail hummingbird has been filmed in full for the first time.
The spatuletail hummingbird is among the most rare and striking of birds.
By using a high speed camera, a BBC natural history film crew was the first to capture the mating sequence in super slow motion.
The crew also filmed a male advertising in front of a female, and solved a mystery of how the male birds make a snapping sound during the display.
The mating display of the marvellous spatuletail hummingbird (Loddigesia mirabilis) is captured for the BBC natural history series
His body is the size of a slightly fluffy ping-pong ball. His beak is the size of a matchstick. He is just tiny. And quite shy
Life researcher Nikki Waldron
The species lives in just a few locations in Peru, and is unusual not just because of its rarity, but also because of its extreme mating behaviour.
Unusually among hummingbirds, the bird has just four tail feathers.
In males, two of these feathers grow to three or four times the bird's body length, each ending in a large violet-blue disc; the spatule.
In an amazing display, a male then advertises its quality as a mate to a female by hovering in front of her while furiously waving his spatules about.
"It's one of the most extreme displays," says Mrs Nikki Waldron, a researcher who helped film the behaviour for the programme.
"As part of his dance he'll jump backward and forwards in the air over a branch and make a snapping sound in the air."
Shaking his tail feathers
"It was thought he actually snapped those spatule discs together to generate the noise."
However, the high speed film of the mating sequence, captured at hundreds of frames per second, reveals that not to be true.
"When we filmed them in super high speed we realised that although the spatules wobble very closely together, the noise is actually coming from his mouth. That was the first time anybody had seen that," says Mrs Waldron.
The BBC camera team was also the first to record the male marvellous spatuletail hummingbird displaying to a female, and his whole mating display from start to finish.
Low light conditions and the tiny size of the bird made filming especially challenging.
"It's particularly tricky, in that his body is the size of a slightly fluffy ping-pong ball. His beak is the size of a matchstick. He is just tiny. And quite shy," says Mrs Waldron.
He'll stand up and go da da da and it'll all be over and he'll be sitting down for an hour
Life researcher Nikki Waldron
"Hummingbirds do everything at super high speed. He would do a dance with a twig where he hops over and over backwards and forwards across it mid air. He'd do that 14 times in seven seconds. It's really really quick."
The display costs so much energy that the males struggle to maintain it.
"He'll stand up and go da da da and you'll hear snap snap snap from his beak and it'll all be over and he'll be sitting down for an hour."
To film the sequence Mrs Waldron and cameraman Mark Payne Gill spent two weeks in the cloud forest, near Lake Pomacochas in central Peru.
Filming from a bush, with camera tripods lashed to trees to prevent them tumbling downhill, the pair would arrive before dawn to capture the display, which occurred each morning at 7am.
Later in the trip, they were joined by Jason Ellson, who operated the high speed camera.
A less marvellous female
Before the arrival of the BBC crew, the bird had only been filmed rarely before using a normal speed camera.
Local expert Santos Montenegro helped the BBC crew find and film the enigmatic bird.
Once a potato farmer, Mr Montenegro now grows a host of local plants to attract around 30 species of bird life.
Much remains to be discovered about the species.
"There's hardly anything known about it," says Mrs Waldron.
For example, it isn't known if the males regrow their extraordinary tail feathers each year, or whether they can attract females if one is missing.
Nor is it clear where the females go when not attracted to the males' territories, known as leks.
Cloud forest, Peru
Working with local conservation charity ECOAN (Association of Andean Ecosystems), Mr Montenegro is also helping to educate children in the area to protect rather than attack the birds for fun.
"It's a poor area. The kids, instead of playing Nintendo DS's, they'd shoot hummingbirds with catapults," explains Mrs Waldron.
"But now they've realised they can make a bit of money from tourists, it's completely changed the culture. If any of the kids get caught with a sling shot they get teased by the other kids."
The "display of the marvellous spatuletail humming bird" is broadcast within the Birds episode of the BBC series Lifeat 2100BST on BBC One on Monday 9 November.