Oates J F, Trocco T F
Folia Primatol (Basel). 1983;40(1-2):83-113. doi: 10.1159/000156092.
Field recordings of male loud calls (or roars) from each major form of black-and-white colobus monkey have been analyzed spectrographically, and features of tempo and pitch measured. Considered together with data on cranial dimensions, coat pattern, and geographical distribution, the results of this analysis suggest that there are five species of black-and-white colobus: Colobus angolensis, C. guereza, C. polykomos, C. satanas, and C. vellerosus. C. guereza and C. vellerosus may have differentiated most recently during a major arid event prior to the last Pleistocene glacial maximum; they have an identical low-pitched roar which we consider to be a shared, derived character. The other species, of which C. satanas has the most distinct roar, may belong to older lineages.
对每种主要黑白疣猴雄性大声呼叫（或吼声）的野外录音进行了光谱分析，并测量了节奏和音高特征。结合有关颅骨尺寸、皮毛图案和地理分布的数据，该分析结果表明有五种黑白疣猴：安哥拉疣猴、东黑白疣猴、多疣黑白疣猴、撒旦黑白疣猴和白臀黑白疣猴。东黑白疣猴和白臀黑白疣猴可能是在上新世末次冰期最大值之前的一次重大干旱事件中最近分化出来的；它们有相同的低调吼声，我们认为这是一个共同的衍生特征。其他物种，其中撒旦黑白疣猴的吼声最为独特，可能属于较古老的谱系。
