Photo/IllutrationA tanuki raccoon dog in the coastal area of Watari, Miyagi Prefecture, south of Sendai, in February 2015 (Provided by Hideki Hiraizumi, a member of the research team)

  • Photo/Illustraion

SENDAI--When the massive tsunami in 2011 washed away the crops, trees and weeds along the fertile coastal plain here, most thought that it would take many years for the ecosystem to recover.

“Tanuki” raccoon dogs and other small mammals that lived among the lush beach plants, farmland and pine forests, which served as windbreaks, were also swept away in the tsunami spawned by the Great East Japan Earthquake.

Now, researchers revealed that the tanuki returned as quickly as two years after the tsunami. Their research paper was published in the Japanese Journal of Conservation Ecology on July 23.

In February 2013, a team of ecologists, including Seiki Takatsuki, a former Azabu University professor of mammalogy, and Yoshihiko Hirabuki, professor of plant ecology at Tohoku Gakuin University, found two "toilet" spots of two tanuki packs in the Minami-Gamo district in Sendai's Miyagino Ward and Iwanuma's Terashima district.

A pack of tanuki has a habit of defecating in the same spot.

The packs of tanuki were in areas where plants were rapidly taking over the tsunami-ravaged land, sprouting again from remaining roots from vegetation or from seeds carried and left behind by the tsunami.

Scholars believed tanukis from inland areas adapted to such a sparse new environment and made it their home.

The team collected droppings from both locations from summer 2013 through spring 2014 and analyzed the diets of the raccoon dogs.

The omnivorous animals in the two areas were feasting on mice and insects, as well as Rosa luciae, a low-growing bush of the rose family that once grew on the beach, and berries of pokeweed, a naturalized plant that is relatively new to the area.

The tanukis were also eating grains of rice and wheat that are believed to have germinated on former farms.

During the survey, one of the packs in Minami-Gamo changed its toilet spot, probably due to the large-scale reconstruction work for seawalls and a sewage facility in the area, as patches of regenerated greenery were uprooted by heavy machinery.

The droppings of the Minami-Gamo tanukis suggested that they were also feeding on leftovers and trash from reconstruction workers, as 10 to 20 percent of their fecal content came from man-made materials, such as aluminum foil and plastic bags.

Scholars say more footprints and tanuki droppings have been spotted along the plain in recent months, proving that the raccoon dogs are thriving amid the ongoing reconstruction work.

“Tanukis are prompting us humans to consider how we should reconcile the conservation of coastal ecology with the reconstruction projects,” Takatsuki said.