The mating system of Crocidura shantungensis in a salt marsh in northern Taiwan: From the perspective of spatial patterns

The knowledge on the mating systems of shrews is insufficient, especially for species living in sub-tropic or tropic areas. Previous studies have hypothesized that the mating systems of Crocidurae in those regions should be monogamous or promiscuous. We tested the hypothesis by investigating the spatial patterns of Crocidura shantungensis in a salt marsh in Northern Taiwan during the reproductive season. The spatial organizations of forty shrews were monitored with mark-and-recapture methods during March-July, 2006. The maximum range and home range size of males was slightly larger than females (p=0.049, p=0.06). The mean overlapping areas were larger with opposite than same sex in females, but not in males (MCP: p=0.024, p=0.501; 50% fixed kernel area: p=0.049, p=0.64). The numbers of overlapping individuals were lower with same than opposite sex in females (MCP: p=0.021; 50% fixed kernel: p=0.019). The numbers of overlapping individuals were higher with same sex than opposite sex. However, this result was only significant in MCP method (p=0.013), not in 50% fixed kernel method (p=0.433). The distance between activity centers of same sex was remarkable in females (p=0.004). The results suggested that the mating system of C. shantungensis was likely facultative monogamy or effectively polygyny. A further test using molecular markers is underway to support the spatial patterns.

Key words: mating system, Crocidura shantungensis, spatial pattern