First, it is important to understand the state of legislature concerning invasive alien species in Japan.

For a country that faces numerous threats from introduced species, Japan has generally been very slow to enact measures to fix the problem and preserve its own ecological heritage. First we had the Plant Protection Act, which dealt with oraganisms harmful to agriculture, as well as the Livestock Epidemic Prevention Act, which dealt with preventing epidemics in livestock. However, these laws had highly specialized objectives, and didn’t really address the overall problem posed by invasive species in Japan as a whole.

It wasn’t relatively recently that increasing research demonstrating the adverse effects of invasive alien species on the native Japanese ecology (of which I have actually contributed) led the Japanese government to really start looking carefully at the overall problem of invasive species and the implications they hold for the ecology here.

An in depth investigation into the effects of invasive species was launched, and there was coordination between various ministries and agencies to this end. In 2002, the Japanese Ministry of Environment summarized it’s findings in a report entitled “Policies Regarding Invasive Alien Species.” This in turn led to the “Draft Legislation Pertaining to the Prevention of adverse effects on Ecosystems caused by Invasive Alien Species,” which was submitted in 2004, approved, and subsequently put into effect in 2005.

The aim of this legislation is to impose regulations on the transport, raising, import, carrying, and sale of certain invasive alien organisms. There are even provisions contained in the act that call for the eradication of invasive species. The legislation stipulates that an “invasive alien species” is defined as “species which exists outside of their original habitats or breeding areas due to having been introduced to Japan from foreign countries.”

The legislation, however, is not all inclusive. Only certain selected items are subject to these regulations, and these specified items are put onto a “watch list.” Items on the list include various animals, fish, insects, parasites, eggs, seeds, and even the organs of some organisms. There was an original designation of only 37 invasive alien species made in June, 2005, and an additional 47 specified species included in December, 2005. Additional species have been added since, but it has generally been slow going and some dangerous organisms are still not targeted by the new laws.

The selection of organisms for inclusion on this list is conducted by a panel of experts, including biologists, conservationists, and forestry officials, as well as individuals with relevant specialized knowledge or experience. Only specified items on this watch list are controlled. If something is not on this list, it is not subject to the law. Species that are not technically on the list, but are related, can be subject for immediate review by the panel.

To my knowledge, kangaroos are not yet a species included on this watch list and as such are excluded from regulations. I think one challenge facing any sort of adoption of regulations on kangaroos is that typically it has to be shown that the species in question poses some sort of threat to either humans, the environment, or to agriculture. I do not think this can be demonstrably shown to be the case with these Japanese kangaroos at this point. One or even a small group of the animals are unlikely to cause much significant ecological damage unless they start breeding and increasing in number.

Unless the kangaroos start popping up in other areas, start breeding on their own, or can be shown to be a threat, they are probably not going to added to the list. Even if legislature is put into effect against the kangaroos at some point in the future, the law stipulates that anyone who has legally owned a banned animal since before the law’s enactment is permitted to continue raising that animal for no more than one generation unless it can be shown that the animal in question will outlive its owner (which is a very real possibility with animals with long lifespans).

Kangaroos live reasonable long lives, and a lot of people in Japan own them currently, so law or no law, it seems that we could have them popping up from time to time into the foreseeable future.

Anyway, hope this has shed some light on the subject for you.

That was so funny I almost spilt Mr. Pibb out of my nose, BTW. “Thanks” a lot, Kittenz.

Thank you for the column, Mystery_Man. Great, as always. Yes, it does look like we have escaped pets here. Most probably Wallabies but I will not rule out Kangaroos. Like Mr. Obara said, Kangaroos can be very adaptable.

Particulalry Eatern Greys.

Maybe the Japanese parliament will reconsider its stance on owning and selling these critters now that there is very reliable evidence that some escaped pets are roaming around Dai Nippon, wouldn’t you think, Brent???