"Long before it's in the papers"
June 04, 2011

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Bird’s mating dance leaves scientists goggle-eyed

June 4, 2011
Courtesy of UCLA
and World Science staff

A small bird called a golden-collared man­a­kin pe­r­forms a tough, com­plex, tir­ing court­ship dance that leaves its heart rate at some of the high­est lev­els in the avi­an world, bi­ol­o­gists say.

“The male jumps like he’s been shot out of a can­non,” said Bar­ney Schlin­ger of the Un­ivers­ity of Cal­i­for­nia Los An­ge­les. “He sails like an ac­ro­bat and lands pe­r­fectly on a pe­rch, like a gym­nast land­ing a flaw­less dis­mount. Not only is there pow­er to his mus­cle con­trac­tions but in­cred­i­ble speed.”

A male gol­den-col­lared ma­n­a­kin. (Pho­to cour­tesy UC­LA)

A small bird called a golden-collared manakin performs a tough, complex, tiring courtship dance that leaves its heart rate at some of the highest levels in the avian world, biologists say. “The male jumps like he’s been shot out of a cannon,” said Barney Schlinger of the University of California Los Angeles. “It’s exquisite. He sails like an acrobat and lands perfectly on a perch, like a gymnast landing a flawless dismount. Not only is there power to his muscle contractions but incredible speed as well.” Subtle differences in dance performance spell the difference between romantic success and rejection, Schlinger and other researchers report in the advance online issue of the research journal Proceedings of the Royal Society B. “The females prefer the males that perform the elements of the dance faster and demonstrate better motor coordination,” said lead author Julia Barske, a graduate student and doctoral candidate at the university. “Females prefer more active males that do more courtship activity.” “Julia’s data show that the females select the males that completed elements of the courtship dance in 50 milliseconds (thousandths of a second) over the males that took 80 milliseconds,” Schlinger added. The dance reveals the male’s speed and coordination, Schlinger said. Using miniature telemetry devices, Barske measured the birds’ heart rates and found that while the heart rate is normally 600 beats per minute or lower, during the courtship display it can go as high as 1,300 beats per minute. “This heart rate is extremely high; in the avian world, only hummingbirds have heart rates of 1,300 beats per minute,” Barske said. “Our data suggest the courtship display is a proxy for survival capability,” Schlinger said. “To survive in the wild, it’s an advantage to have extra neuromuscular capability. Being faster can enable a golden-collared manakin to escape a predator.” Golden-collared manakins, or Manacus vitellinus, live in Panama, Colombia and Costa Rica. For the research, Barske spent three months in a rainforest near Gamboa, a town along the Panama Canal, not far from Panama City. She watched the birds for several hours daily, filmed 18 male birds with high-speed video and ultra–high-speed cameras that produced 125 images per second, and recorded their courtship success. Barske can tell the birds apart from their leg rings and the location of their display arenas. Golden-collared manakins live up to 14 years in the wild. During the dance, several males gather in a small area, and each jumps from small tree to small tree while making a fast, loud snapping sound with his wings. He also does this wing-snap while perched. When the male lands on a perch, he rapidly turns to expose his feathers to the female. It’s “intense, physically elaborate, complex, accurate, fast behavior,” Schlinger said. The male performs these feats “not necessarily because he wants to, but because that’s what the female rewards,” Schlinger said. “If the female rewards a slightly faster behavior, then the males will get faster. We propose that elaborate, acrobatic courtship dances evolve because they reflect the motor skills and cardiovascular function of males.” During the six-month breeding season, a female will observe a group of four to six males — “the patch of forest erupts in sound,” Schlinger said — and choose one to mate with. The male offers no help in raising offspring. Schlinger has studied golden-collared manakins for 16 years because he “was so impressed with their fantastic behavior,” he said. “Here is a very small, 17-gram bird that is living 14 years in the rain forest, telling everybody where they are… they are there year after year.” Female golden-collared manakins have a larger visual processing area in the brain than males, Schlinger’s previous research has shown, suggesting females have a fast visual processing speed that lets them detect slight differences in the male’s dance.