photo by Kiyoto Sawada

Sado Island, Japan, is inhabited by seven species of snakes, the largest number in any isolated island in Japan, except for the subtropical Ryukyu Archipelago. Researchers from University of Tsukuba and Niigata University conducted a 5-year field study to investigate the ecology of each snake species. Their results showed that differences in feeding habits, as well as differences in activity times and locations, are critical factors in the coexistence of multiple snake species.

Tsukuba, Japan—"Niche partitioning" is one of the most fundamental and essential ecological concepts in explaining how diverse organisms coexist and how resources such as activity time, location, and prey differ from those of other species. In the case of snakes, niche partitioning of prey resources has been considered the major factor enabling the coexistence of multiple species, although the importance of time and location of activity has also been indicated. Nevertheless, there have been no comprehensive studies on the niche partitioning of the three significant resources (time, habitat, and diet) of terrestrial snakes.

In this investigation, the researchers designated Sado Island, which has the largest number of snake species among any Japanese island, except for the subtropical Ryukyu Archipelago, as the study site and conducted a 5-year survey to determine when, where, and how seven species of snakes [Euprepiophis conspicillata (Japanese forest rat snake), Elaphe climacophora (Japanese rat snake), Elaphe quadrivirgata (Japanese striped snake), Gloydius blomhoffii (Japanese pit viper), Hebius vibakari (Japanese odd-scaled snake), Lycodon orientalis (Oriental odd-tooth snake), and Rhabdophis tigrinus (tiger keelback snake)] live and what they feed on.

Researchers identified niche complementarity among species with considerable overlap in food resources, reducing the overlap in habitat, time of activity, and season.

This study empirically revealed that terrestrial snakes coexist through "multidimensional niche partitioning," in which a high overlap in one niche dimension should be compensated by a low overlap in at least one of the other niche dimensions. These results indicate the need to protect different types of resources to conserve snakes, which are facing a decline worldwide.

###
This study was supported by JST SPRING [grant number JPMJSP2124] and JSPS KAKEN [grant number 22J11120].

Original Paper

Title of original paper:

Multidimensional Niche Partitioning Allows Coexistence of Multiple Snake Species

Journal:

Journal of Zoology

DOI:

10.1111/jzo.13259

Correspondence

Assistant Professor SAWADA Kiyoto
Institute of Life and Environmental Sciences, University of Tsukuba

Associate Professor ABE Harue
Sado Island Center for Ecological Sustainability, Niigata University

Related Link

Institute of Life and Environmental Sciences