Svensson Magdalena S, Butynski Thomas M, de Jong Yvonne A, Bearder Simon K, Schneiderová Irena, Nijman Vincent
Nocturnal Primate Research Group, Oxford Brookes University, Oxford, United Kingdom,
Nocturnal Primate Research Group, Oxford Brookes University, Oxford, United Kingdom.
Folia Primatol (Basel). 2019;90(5):300-318. doi: 10.1159/000499654. Epub 2019 Aug 15.
Like other nocturnal primates, many species of galago (Galagidae) are phenotypically cryptic, making their taxonomic status difficult to resolve. Recent taxonomic work has disentangled some of the confusion. This has resulted in an increase in the number of recognised galago species. The most widespread galago species, and indeed the most widespread nocturnal primate, is the northern lesser galago (Galago senegalensis) whose geographic range stretches >7,000 km across Africa. Based on morphology, 4 subspecies are currently recognised: G. s. senegalensis, G. s. braccatus, G. s. sotikae and G. s. dunni. We explore geographic and subspecific acoustic variation in G. senegalensis, testing three hypotheses: isolation by distance, genetic basis, and isolation by barrier. There is statistical support for isolation by distance for 2 of 4 call parameters (fundamental frequency and unit length). Geographic distance explains a moderate amount of the acoustic variation. Discriminant function analysis provides some degree of separation of geographic regions and subspecies, but the percentage of misdesignation is high. Despite having (putative) parapatric geographic ranges, the most pronounced acoustic differences are between G. s. senegalensis and G. s. dunni. The findings suggest that the Eastern Rift Valley and Niger River are significant barriers for G. senegalensis. The acoustic structures of the loud calls of 121 individuals from 28 widespread sites are not significantly different. Although this makes it unlikely that additional unrecognised species occur within G. senegalensis at the sites sampled, vast areas of the geographic range remain unsampled. We show that wide-ranging species do not necessarily exhibit large amounts of variation in their vocal repertoire. This pattern may also be present in nocturnal primates with smaller geographic ranges.
与其他夜行性灵长类动物一样，许多婴猴属（婴猴科）物种在表型上难以区分，这使得它们的分类地位难以确定。最近的分类学研究消除了一些混淆。这导致被认可的婴猴物种数量有所增加。分布最广的婴猴物种，实际上也是分布最广的夜行性灵长类动物，是北方小婴猴（塞内加尔婴猴），其地理分布范围横跨非洲超过7000公里。基于形态学，目前认可4个亚种：塞内加尔婴猴指名亚种、布拉卡图斯婴猴、索蒂凯婴猴和邓氏婴猴。我们探究了塞内加尔婴猴的地理和亚种声学变异，检验了三个假设：距离隔离、遗传基础和屏障隔离。对于4个叫声参数中的2个（基频和单元长度），有距离隔离的统计学支持。地理距离解释了一定程度的声学变异。判别函数分析在一定程度上能区分地理区域和亚种，但误判率较高。尽管（假定）地理分布范围相邻，但塞内加尔婴猴指名亚种和邓氏婴猴之间的声学差异最为明显。研究结果表明，东非大裂谷和尼日尔河是塞内加尔婴猴的重要屏障。来自28个广泛分布地点的121只个体的大声呼叫的声学结构没有显著差异。尽管这使得在采样地点的塞内加尔婴猴不太可能存在未被识别的额外物种，但地理分布范围的大片区域仍未采样。我们表明，分布广泛的物种在其发声库中不一定表现出大量变异。这种模式也可能存在于地理分布范围较小的夜行性灵长类动物中。
