I was thinking about Finsch's Bulbul because the shape looks quite compact and short-tailed, but the habitat doesn't sound right - Olive-winged would be more likely. I'm not seeing the usual streaked ear coverts, although that could be because it's apparently a young bird. The bill is also a bit stubby for that species. However, the pale yellow throat, green tones on the wing, yellow vent and green under-tail would fit.