Rich bat life discovered in Tomamu: 10 species identified

A bat survey conducted at Horoka Tomamu Sanrin, a conservation and biodiversity project in Tomamu, Hokkaido, has revealed a high diversity of bats. Ten species have been identified.

The survey was conducted in early August and the results far exceeded expectations, even though the work was interrupted several times by heavy rain. Before the survey only one type of bat, the low-flying Ussuri tube-nosed forest bat, had been identified in the area. 

The director of the survey, Prof. David Hill of Kyoto University Primate Research Institute, used mist nets and harp traps to capture over 50 bats over a period of 8 days. An Autobat acoustic lure — a device that broadcasts simulated bat social calls — was used to attract the animals. Prof. Hill gently released each bat after recording its species, sex, reproductive status and maturity etc.

The majority of those caught were Ussuri tube-nosed bats, but there were also Ikonnikov's, fraternal myotis, Ussuri whiskered, northern, Japanese long-eared, Asian barbastelles, and Hilgendorf's tube-nosed bats. The greater horseshoe bat and birdlike noctule were identified from their calls.

Prof Hill, who is also researching Kotengu on Yakushima, was able to take 28 small samples of wing tissue for DNA analysis. This will be used to determine kin relationships and population dynamics.

Many people in Japan associate Hokkaido with large animals such as bears and deer. They forget how many wonderful smaller animals we have, said Dr Masumi Maruo Holledge of the Horoka Tomamu Sanrin. Prof. Hill explained that bats play a major role in forest ecosystems by eating large numbers of insects and so controlling their populations.

Three of the bats discovered at Horoka Tomamu Sanrin — birdlike noctule, Hilgendorf's tube-nosed, and Ussuri whiskered bat — are listed as threatened or endangered in the International and Japanese Ministry of the Environment Red Lists. Many countries have been losing their bat populations in recent years, added Dr Maruo Holledge. It's vital that we keep our bats and look after them!

(Press Release by Horoka Tomamu Montane Forest, 27 August 2012. Digital copy at https://horoka.org/press1.html)