Time for something different, but actually closely related to hybridization: species concepts. Today, I came across a press release from the Cornell Lab of Ornithology. It concerns the Superb Bird-of-Paradise (Lophorina superba), a bird species endemic to New Guinea and known for its peculiar mating display. It can be best described as a jumping black and fluorescent blue smiley-face (click on the picture to see the courtship display in action or click here).
Scientist Ed Scholes and photographer Tim Laman documented this courtship display for two populations: the western population in the Arfak Mountains and the more common population that occurs all across the island. They noted striking differences between birds from these populations. Scholes remarks: “The courtship dance is different. The vocalizations are different. Even the shape of the displaying male is different.” Pictures show that the shape is indeed different. The Western male has a crescent shape, while the common male is more oval-shaped.
Based on their observations, Scholes and Laman both believe that the Western population should be considered a separate species. When I read this, I had to frown. Can you really describe a new species based on dancing? Then taxonomists could add an extra species concept to the long list already available: the Dancing Species Concept. According to this species concept, I would be considered member of a separate species compared to some of my fellow Homo sapiens. My dancing moves are – euphemistically speaking – not so good…
Of course, I am writing this jokingly. The distinct dancing behaviors of Superb Birds-of-Paradise fit within the Species Recognition Concept. The display ensures that females chose the ‘right’ species. It would be interesting to see how females from the Western population respond to displaying males from the widespread population. If they ignoring the jumping smiley, it would provide extra evidence for the description of a new species.
In fact, a recent genetic study showed that the Western population is genetically distinct from the widespread population. “The timing of this DNA-based study is perfect,” said Ed Scholes, “because it is great to have our field observations supported by solid genetic evidence. We really appreciate this in-depth study of the evolutionary relationships among the different forms of Superb Bird-of-Paradise.” To be continued.
Irestedt, M., Batalha-Filho, H., Ericson, P. G., Christidis, L. & Schodde, R. 2017. Phylogeny, biogeography and taxonomic consequences in a bird-of-paradise species complex, Lophorina–Ptiloris (Aves: Paradisaeidae). Zoological Journal of the Linnean Society.