“3220 flight kilometres away from Peninsular Malaysia, let’s meet two foraging, ubiquitous quite similar bird cousins in Taiwan – Light-vented Bulbul (Pycnonotus sinensis formosae) and Styan’s Bulbul (Pycnonotus taivanus).
“Four subspecies of Light-vented Bulbul also known as Chinese Bulbul are represented under this order, based on their respective resident locations.
“They are generally listed as follows: P. sinensis sinensis – high concentrations in Central and East China; P. sinensis hainanus – South East China and N. Vietnam; P. sinensis orii – S. Ryukyu Island, Japan (Okinawa Yaeyama Island); P. sinensis formosae – North, West and Central Taiwan.
“In Taiwan, P. sinensis formosae populations have been found to be prolific along the western region/ coast, to include Taipei north to as far south as Kaohsiung, where I had visited and observed (below).
“Strangely after crossing into Pingtung County, this subspecies frizzled out quite suddenly, only to be replaced by its endemic cousin, Styan’s Bulbul (below).
“Why is it so?
“ROC Taiwan or Formosa as formally known is a mountainous island with 286 mountain summits, forming prominent long mountain ranges humping the eastern seaboard (below). The island was formed millions of years ago when a piece of landmass fractured and floated away from an ancient, huge continent; carrying with it, residues of flora and fauna life within to eventually account for their rich and high percentage of endemism.
“Geographically, it suggests these mountains, many more than 3000 metres a.s.l. are simply too high for lowland birds to cross over. As such, Styan’s Bulbul found therein, remain and congregate mainly along the eastern, lowland side and lowlands down south (Pingtung County); while its cousin, Light-vented Bulbul live separately behind the western divide of the insurmountable high mountain ranges.
“It is mentioned that these two species hybridise. Such natural occurrence would be more likely observed down south, in the Pingtung County lowlands and peninsular area. So far in my travels, I have not encountered any hybrids to show/photograph.
“Any P. sinensis formosae species seen in P.taivanus regions and vice versa is considered and accepted to be introduced species, popularly released during religious observance.
“A visit to Taichung Metropolitan Park, on the Western side of Taiwan, saw large flocks of Light-vented Bulbuls indulged in a profusion of early spring, Japanese figs (Ficus superba varijaponica), that sprouted from every conceivable branch of figging trees found (above, below).
“These sub-endemics flocked and foraged in waves. As they partook of those succulent fruits, they provided great viewing opportunities of their distinctive head-plumaged features, that so distinguished them apart from their endemic cousins – Pycnonotus taivanus.
“Here are several views of Light-vented Bulbul with photographic plumaged descriptions.
“Perched on fig branch, P. sinensis formosae wears a large, black forehead, cap patch surrounded by a rear bonnet like broad, white band (below).
“A prominent view of the bird’s crown is shown here (below).
“Under shade of tree, front view of this frugivore reflects a white throat with brown, broad chest band and somewhat diffused, similar coloured belly, terminating into a whitish vent (below).
“In Chiayi County, mixed flocks of birds were observed enjoying breakfast of different fig fruit species at entrance to the Lantan Reservoir.
“In this location, a horn coloured sub-adult P. sinensis formosae, in an early October morning photograph, presented a clear demarcation of brown chest- band (below).
“In central region of Yunlin County, a prominent side view of a puffed up P. sinensis formosae was observed in a crisped April morning (below).
“Do join me in next article to visit the ancient, historical town of Hengchun, Pingtung Peninsula; to read the ornithological history of the endemic Styan’s Bulbul species- now classified under Vulnerable category (IUCN) and to scout and check out their foraging habits.”
Avian Writer Daisy O’Neill
11th April 2017
Copyright article and all copy images – Courtesy of Daisy O’Neill Bird Conservation Fund
Ref: Internet Bird Collection
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