Friday, April 17, 2009

There goes the neighbourhood

Deer and monkeys invade Japan's high mountains, decimating alpine plants and the birds that live off them

Just below Kita-dake's summit, a snow ptarmigan and her chick were taking a dust bath in the middle of the path. A beady glare from the hen assured me that she had no intention of moving aside; it was for me to walk round the birds. Unthreatened by predators in their high alpine habitat since the last ice age, snow ptarmigan (raicho in Japanese) have little fear of people.

On Japan's second-highest mountain, this was no unusual encounter in the 1990s. It might be now. When Nakamura Hiroshi visited Kita-dake in October 2003, he found none of the friendly birds on a mountainside that once harboured one of the largest colonies in the Japan Alps. Instead, the ground was covered with monkey droppings and deer tracks, something he'd never seen before at this altitude.


Nakamura, a professor at Shinshū University, has been surveying Japanese snow ptarmigan populations since 1981. But it is only in the last five to ten years that monkeys and deer have started to move up beyond the treeline into the alpine zone of creeping pine and alpine shrubs. The implications for snow ptarmigan, which depend on those shrubs for cover and food, are ominous, he believes.

Writing in Yama to Keikoku, Nakamura suggests that Japan's high mountains are being invaded on a broad front. In September 2002, he saw 30 monkeys stuffing themselves on bilberries (kuromame-no-ki) near the top of Otenshō-dake, an almost-3000er in the Northern Alps, Never before had he seen a monkey troop at such a height.

Then in June 2005, he made a traverse between Hijiri-dake and Tekari, two "famous mountains" in the Southern Alps. Deer tracks were seen everywhere along the connecting ridges and all the alpine flowers had been grazed away, except for the poisonous species. The damage was most severe towards the south of the range, between Izaru-ga-dake and Tekari, where all the flower fields (hanabatake) marked on the map had been erased. "And what has already happened in the Southern Alps is only a matter of time in the Northern Alps," warns Nakamura.

The snow ptarmigan are menaced on all sides. Monkeys and deer are cropping their food supply. Kestrels and crows, also newcomers to the mountaintops, are raiding their nests. Foxes are hunting them. Monkeys have been seen stalking the unwary birds; they may have acquired a taste for fresh ptarmigan.

In the past, all these predators and competitors stayed down in the beech and oak woods at the mountain's foot. Dark and inhospitable, the evergreen forests at the middle altitudes kept them from foraging higher up. What has now pushed them beyond their traditional bounds?

Professor Nakamura believes that modern agriculture has caused the population of wild animals to explode. The decline of hunting has also helped numbers to increase. "But it's not the wild animals that have changed their habits," he concludes. "It's that we Japanese have moved from a co-existence with nature to a wholly human-centred way of life."

References

危機に瀕するライチョウ:日本の高山で、今何がおきているのか ("Snow ptarmigan on the brink of disaster – what is happening in Japan's high mountains") article by Professor Nakamura Hiroshi (中村浩志)in Yama to Keikoku, one of Japan's leading mountaineering magazines, January 2007 edition.

Photos of flowers taken on or around Kita-dake between 1991 and 1995; photo of raicho from Natural Monuments of Japan (Kodansha); photo of raicho and yama-skiers by Sunnybeauty

Update

In May 2009, a snow ptarmigan was spotted on Hakusan for the first time in 70 years. The bird became extinct on Hokuriku's highest mountain in the early Showa years. Full report in the Chunichi Shinbun

9 comments:

hanameizan said...

Your account matches my own experience. In the whole of last year, I saw raicho only a few times (Kasagatake, Washiba, Norikura, Goryu), and none in the whole traverse of the Southern Alps.

In the early 90s, I saw raicho around Kitadake on several occasions.

wes said...

I certainly didn't see any Raicho (or flowers for that matter) on either Hijiri or Tekari. A few years back, I ran into a mother with recently hatched chicks just below the summit of Mt. Warusawa.

Plenty of raicho on Dainich-dake, next to Tateyama.

I"ll definitely keep my eyes out for monkeys, deer, and other sorts of creatures during my alpine ascents this year.

Chris (i-cjw.com) said...

Last September, Kitadake (right up to the summit) was covered with the chewed remains of haimatsu cones. It took a while for my friend & I to figure out that deer, and maybe monkeys, were the culprit. They even told us at the Kitadake-sanso that a bear had been sighted around the mizuba a mere 100m below.

The taxi driver who drove us back blamed it on warmer winters. More offspring survive, putting greater pressure on the food chain, in turn driving animals higher into the mountains in search of food.

Thankfully many raicho, both seen and heard, on Goryu last weekend though!

Project Hyakumeizan said...

Julian, Wes, Chris - many thanks for your comments - it's most interesting to have your personal observations to back up those of Prof. Nakamura. Chris: interesting that the taxi driver brought up the subject of warmer winters. Nakamura's article doesn't mention climate change as a possible factor - although habitats (and treelines) shifting uphill would be expected if average temperatures are rising.... all very thought-provoking.

sunnybeauty said...

It's a great honour for me the photos of raicho and my colleagues have appeared here. The photos were taken during the Japanese Golden Week holidays in 2006. The raicho were busy eating, and they seemed to regard us just as a part of that peaceful nature. I felt happy then because I thought we were accepted. I hope they still live there peacefully like in the photos...

Yubi said...

Interesting! The first thought I had was "global warming" and therefore the possiblity of "lowland" species to reach higher altitudes ....
Thanks for another great post!

Peter (tsubakuro) said...

Two weeks ago at Shirouma Dake there was no shortage of raicho, though there was no shortage of snow either. Of course, Shirouma is in the North Alps.

One other thought might be that in recent years there has been less snow cover in the mountains of Japan. The last three years that I have been visiting the mountains between December and May I have heard several times that there is less snow. Spring and summer have also been warmer too, though even at the end of May temperatures can go below freezing at night.

I wonder if less snow has brought some animals from below to higher elevations due to the increase in competition for food below, as you mentioned there has been a wildlife boom around agricultural areas. It's true that the news has reported increasing problems with boars, bears and even leaches in recent years due to changes in agricultural practices.

Project Hyakumeizan said...

Peter: it's good to hear from you and other correspondents that the raicho isn't (yet) totally extinct. What you say about declining snowcover is also echoed by others - indeed, it's true of Switzerland too, where I'm based. (They say that ski resorts under the 1,500-metre level will soon be history.) The ecological consequences will, as always, be complex and unpredictable. Leeches? Aargh - there goes the neighbourhood. In my many sawa excursions, none of us was ever (knowingly) battened upon by such a creature - although I did hear from two victims that the sawas on the appropriately named Hiru-ga-dake in Tanzawa were full of them...

Peter (tsubakuro) said...

I don't remember so much from my hikes in the South or Central Alps because they were between July and December, but in the North Alps between November and May I have seen plenty of raicho, sometimes four or five around me at once. It seems they are curious to see what a five-legged creature (two legs of flesh, three of metal) is doing at the edge of a cliff for ten minutes.

There was a news story about a kind of leech that inhabits agricultural land that gets in your boots and sucks a big meal without you noticing until you come home and take off your socks. The story said that cases of people finding these leeches attached to them were increasing in rural areas near the mountain sides. The thign was that they can live amidst the grass and in the trees, not only in water.