IT IS WELL KNOWN among ornithologists that there are many migratory birds that winter in the Indian plains and breed in summer in Tibet, Mongolia and Siberia; but it is believed that for the most part these birds cross the lower passes of the Himalaya and fly through the canyons. There were no reports of cranes that crossed the Himalaya, not only before but even after the war until about 1958.
In the fall of 1958, the Japanese Alpine Club sent a two-man reconnaissance party to the east ridge of Himalchuli to prepare for an attempt on that peak in the pre-monsoon season the following year. The two members of the reconnaissance party, Ichiro Kanesaka and Shojiro Ishizaka, wrote a report stating that ‘the monsoon lifts with a flight of swans’. They wrote that when the monsoon lifted and wintry weather started to set in, large swans formed into a great V-shaped phalanx were crossing the upper air over the Himalaya, headed from Tibet southward toward India. When I saw that report, I thought that if the birds were crossing from their breeding areas in Mongolia and Tibet to their winter grounds in India in the post-monsoon season, then they must return from south to north in the pre-monsoon season.
I then started thinking that maybe the timing of the birds’ migration across the Himalaya could be used to help forecast the weather for climbing the high peaks. I started looking for information the subject, and was intrigued by scenes of aquatic birds such as cranes, wild ducks and swans pausing during the southward journey toward warmer lands in early October in Haslund Christensen’s More Travel and Adventures in Mongolia (London, 1936).
However, during the Himalchuli expedition the following year (1959), in which I participated as deputy leader, migratory birds were not observed. Neither did we observe migratory birds during the 1970 Japanese Mount Everest Expedition.
Colour Plates 1-2-3
Photographic evidence of crane, and subsequent reaction
During the intervening 10 year interval, I had not heard any reports of cranes or other migratory birds and in fact forgot about them. However, Dr Sen’ya Sumiyoshi, who was with us on the Everest expedition, reported that ‘in the fall of 1969, on a reconnaissance of the route for an attempt on peak P-29 in the fall of the next year, we observed large white migratory birds similar to those that you saw on Himalchuli 10 years ago’. I asked him to obtain photographs as evidence.
Dr Sumiyoshi was the leader of the Osaka University P-29 expedition in the fall of 1970. On 11 and 12 October, he obtained the first photographs by a Japanese of these migratory birds.
After Dr. Sumiyoshi brought the pictures back to Japan, experts identified the birds in the pictures as cranes. At the regular meeting of The Ornithological Society of Japan in March 1976, many ornithologists from the Yamashina Institute for Ornithology and other institutions examined the pictures, and concluded that most of the birds were Demoiselle cranes (Anthropoides virgo), but that some could be Common cranes (Grus grus), and that the 9 birds which made up the formation in one of the pictures might be Siberian cranes (Grus leucogeranus), which were in danger of extinction; that photograph in particular attracted a great deal of attention.
The year before, on 14 June, 1975, I had given a presentation on the birds at the 4th Symposium of the Japan-Nepal Society held in Fukuoka. At that time I identified the birds only as cranes of unknown species. The report on that conference, ‘Symposium Nepal No. 4’, although dated 1975, was not actually printed until June 1976. I incorporated the species identifications from the March 1976 meeting into the printed version.
At about the same time as the P-29 expedition, in early October 1969, in the Takkhola, the local name for the gorge between Annapurna and Dhaulagiri on the upper reaches of the Kali Gandaki, the West German ornithologist Jochen Martens observed the migration of 30, 000 Demoiselle cranes in detail and published his description as ‘Zur kenntnis des Vogelzuges im nepalischen Himalaya’ in the 1971 issue of the German ornithology journal Die Vogelwart pp. 113-128. I learned of this only in 1976, when Prof Hiroyuki Masatomi of the Hokkaido Junior College of Senshu University told me about following my presentation ‘Siberian cranes surmount giant peaks of the Himalaya’.
In the fall of 1976, the Nagano Prefecture Mountaineering Association sent a joint expedition with Iran to Manaslu. Before departure, I advised the expedition’s climbing leader, Nobunori Tamura, that from past data, cranes would cross this mountain region when the monsoon lifted in early October, and if one observed them closely the observations would be useful in predicting good weather in the post-monsoon season.
The method worked beautifully. The expedition started its climbing activity after observing the cranes, and succeeded in climbing to the summit on 12 October. This resulted in an increase in interest in the cranes that cross the Himalaya and a succession of reports followed. It is now known that when the monsoon lifts, tens of thousands of cranes cross over the Manaslu area and the Annapurna - Dhaulagiri area (the upper reaches of the Kali Gandaki).
Some of the mountaineers on those expeditions, such as the members of the Kamoshika Dojin 1979 Dhaulagiri Traverse and Yasuo Kato of the Yeti Dojin 1981 Manaslu Expedition, succeeded in capturing images of the cranes on 8mm movie film, but these were of amateur quality and of limited value in scientific studies.
Several times since then, such as at the 1985 Tsukuba Science Expo, movies of cranes crossing the Himalaya have been shown. Prior to that, in 1978, NHK tentatively planned an expedition to film the cranes for television, but the plan was judged to be uncertain of success and was abandoned.
Video Photography of Cranes over Manaslu
In the fall of 1989, an expedition went to Manaslu for the purpose of full - fledged video photography of migratory cranes. This expedition consisted of 2 cameramen, N. Muraguchi and K. Sakaguchi. They obtained permission to climb the north ridge of Manaslu, climbed up the Manaslu glacier and then set up their base atop a black rock at 5700 m and waited for the cranes. On 9 and 10 October they succeeded in photographing cranes crossing the Himalaya. Their pictures, taken through a 900 mm telephoto lens, were shown under the title ‘The Great Himalaya’. The vision of 2000 Demoiselle cranes crossing the Himalaya taking advantage of upward air currents, were a huge success scientifically as well as artistically. Iwao Okuyama of the Japan Weather Association served as an advisor to that expedition. He analysed the weather on the day of the cranes’ crossing. The results were presented to a symposium of the Society of Mountaineering Meteorology as a joint work of Okuyama, Muraguchi and Matsuda on 15 May, 1991. A summary of that work follows.
(1) Weather conditions on the day of crossing of the Himalaya by Demoiselle cranes :
Analysis of 500mb upper air weather maps of the Northern Hemisphere, together with data from the nearby Chinese Nagqu Weather Station (31° 29' N, 92° 04' E), was used to prepare a sequence of 500mb forecasts for the vicinity of Manaslu (Fig. 2). Previously, Shoichi Ooi of the Meteorological Research Institute had prepared sequences for the days of observed crane crossings in 1958, 1969, 1970 and 1974. At those times the area was in a trough of both temperature and pressure. In 1989 as well, there was a pressure trough and the air temperature was low, but the wind was a relatively weak westerly wind. Since the upward drafts on the leeward sides of mountains are relatively weak on days of bad weather, perhaps the birds were rising on drafts created by reverse winds (this is based on observations at Naike Col).
Looking at the 500mb Northern Hemisphere weather charts, in the low latitude region in which Manaslu is located the gradient of the constant height contours is gradual and there is not a strong dominating large-scale weather pattern, so that local effects tend to dominate in determining where there are updrafts.
Yuji Yamamoto of the JMA Aerological Observatory analysed the weather at the time of the crane crossing in October 1976. He reported as follows. “From the end of September to the beginning of October, looking at 500mb which is about the level of Camp 2, the 5800 m contour started to move southward, reaching the vicinity of 28° N in mid-October. There was a clear trough in the 500mb pattern throughout October; cold air moved down from the north, showing that the season was clearly changing. Based on these data, the crossing of the Himalaya by the cranes is less a sign of the lifting of the monsoon than of the arrival of the new winter season.’ Thus it appears that the flight of the cranes occurs immediately after the upper level wind changes to a westerly wind, indicating that the season has changed.
(2) The mechanism by which cranes cross the Himalaya :
Why do the cranes cross the Himalaya? It appears that doing so permits them to fly a long way using relatively little energy.
This was the opinion of the late Shun’ichi Miyauchi, a former Japan Meteorological Agency official who served as meteorological advisor to the Japan Soaring Association and the Japan Pigeon Racing Society. It is known that recent model gliders can glide a distance equal to about 35 times the starting altitude. This means that a crane that starts from over 8000 m above the Himalaya can glide 300 km.
It is well known that in Japan the weather is best for gliding immediately after the passage of a trough. It is interesting that the cranes also cross the Himalaya during the passage of a trough.
With regard to the effect of temperature, it is known that in pigeon racing energy tends to be dissipated more rapidly in a warm wind; even if it is a bit cold, given a tailwind, flying is easier then. This agrees with the fact that the cranes do not appear to be bothered by a cold west wind.
Updrafts occur in the mountains both on windward slopes, where the air is forced up directly, and leeward of the mountains where suction updrafts form. It appears that cranes crossing the Himalaya often use updrafts that form over glaciers in afternoons.
Martens reported as follows. ‘In the Takkhola, on the upper reaches of the Kali Gandaki, there is a place where the gorge becomes narrow; here a great deal of air is sucked up due to the daytime temperature increase on the Tibetan Plateau; in some places this becomes a strong southerly updraft. When the cranes reach this point on their southward journey, they meet up with the strong headwind, abandon their reverse V phalanx formation and spiral upward for about 20 to 30 minutes. When they reach the layer of westerly wind they re-form into the reverse V-shaped phalanx formation and resume their southward journey.’ Similar rising of cranes using an updraft has been observed over Apfhesan, near Ch’ongjin, in North Korea.
(3) Crane species and migration routes : We think that most of the cranes involved in this trans - Himalaya migration are demoiselle cranes. However, considering where the breeding and wintering grounds are, it would not be surprising if some common cranes are mixed in with them.
Since the present author once commented that it would not be surprising if some Siberian cranes are involved in the trans - Himalaya migration, a strong image that the trans - Himalayan migration involves mainly Siberian cranes developed, but Prof. S. Dillon Ripley of the Smithsonian Institution in America, Chairman of the International Council for Bird Preservation (ICBP), conducted a survey of Nepalese birds together with the Indian ornithologists Dr. Salim Ali and Dr. Biswas, and came to the conclusion that the birds photographed by Dr. Sen’ya Sumiyoshi were common cranes illuminated by light reflected off the snow.
They believe that the Siberian cranes observed in the Bharatpur Bird Reserve on the Ganges Plain are from the group of Siberian cranes that breed on the Ob River and migrate both to and from India across the Hindu Kush, and they are not prepared to change that view unless presented with photographs that show clearer black - and -white wing patterns than observed thus far (this in response to a question transmitted via Dr. Yoshimaro Yamashina of the Yamashina Institute for Ornithology).
As is clear from the observations of cranes over Manaslu reported here, the migration route of the demoiselle cranes heading from the north toward India is clearly fixed from one year to the next and passes over Manaslu and Dhaulagiri, but the reverse route followed from south to north in spring has not been confirmed.
As for the timing of the northward journey, the pre-monsoon climbing season (early May) would be too late for them to arrive in time for breeding. We believe that they probably travel north from mid-March through early April (the cranes at Izumi in Kagoshima Prefecture in Japan fly northward in mid- to late March). The route is believed to be a bit to the west of central Nepal.
Further research is needed on the northward migration routes of cranes that winter in India.
4) International cooperation related to the migration and protection of cranes :
The protection of migratory birds that fly a long way between their breeding and wintering grounds, involving as it does routes that cross over many nations, has always taken precedence over diplomatic issues and become a symbol of peace, even during the Cold War. In particular, cranes, being large conspicuous birds of gentle disposition which are loved by people of many countries, have long been the subject of protection efforts, in large part through the efforts of the International Crane Foundation (ICF).
From 5 to 11 February, 1983, an International Crane Research Conference was sponsored jointly by the ICF, the International Council for Bird Preservation (ICBP) and the Indian Government in Keoladeo Ghana National Park, the national park that contains the famous Bharatpur Bird Reserve known as the wintering ground of Siberian cranes and other birds, near Agra in northwestern India. At this conference, problems relating to the protection and living conditions of cranes in several different parts of the world were discussed, and 18 resolutions were adopted concerning crane species in danger of extinction, directed at the governments responsible in each case. In particular there was a shocking report concerning the attitude of Pakistan, which openly permits the hunting of cranes crossing the Hindu Kush on their way to and from wintering grounds in India, resulting in the killing of thousands of birds.
In 1993, 10 years later, the 5th Ramsar Convention Conference was held in Kushiro, Japan. In conjunction with that conference, an international symposium on ‘The Future of Cranes and Wetlands’ was held in Tokyo and Sapporo, and was highly successful. The main focus at that symposium was on a satellite tracking system, developed in 1990, and subsequently used to track the migration of cranes between their wintering grounds in Japan and their breeding grounds in Russia and China. The tracking survey demonstrated the need for protection of the birds at resting sites along their migration routes.
Ms. Meenakshi Nagendran (ICF researcher), who came from India to participate in that symposium, presented a report titled ‘Satellite Tracking of Common Cranes Migrating North from India’, concerning common cranes that fly north toward their breeding grounds in spring, which attracted a great deal of attention.
(5) On-site survey of cranes migrating over the Kali Gandaki : I was greatly inspired by that symposium, and in September and October of that year (1993) planned a Nepal trek to observe the cranes during their fall migration. With my wife I headed toward Jomsom in the Kali Gandaki valley. At first I thought of trying to observe the cranes flying over Manaslu, which I had climbed in 1956, but since it would take time to obtain official permission to climb, I gave up on that plan and concentrated on observing the cranes around Jomsom. There had been several bird watching expeditions in the area subsequent to the observation by Martens of 30,000 birds in 1969, referred to above. In 1973, M.S.A. Beaman led an Ornithological Cambridge Expedition into the Kali Gandaki and counted, 2200 birds from 27 September to 14 October. In 1978, J.M. Tiollay reported observing 61,000 birds in 12 days from 24 September to 5 October. In the fall of 1992, an NHK film team, with the cooperation of Prof. Toru Kondo of the Mustang Development Service Association, which runs a large-scale farm and provides training to local people near Jomsom, succeeded in filming the cranes during their migration. So I thought that if I concentrated on the area around Jomsom I could not go wrong.
I decided to observe the cranes around Yak Kharka (4,300 to 4, 900 m), on the way to Dapa col where Martens had done his observing. Before going there, I met sarus crane expert Rajendra N. Suwal at Tribhavan University in Kathmandu, and received his advice concerning the observation location.
1 October we flew from Pokhara to Jomsom, and stayed overnight in the village of Marpha. We didn’t have to wait long: that evening we caught a glimpse of a formation of cranes flying overhead. The next day we climbed to Alubari at 3900 m, and the day after that set our base camp up at about 4300 m. The next 3 days, we observed many cranes, as follows :
3rd day ..... 3010 birds
4th day ..... 1680 birds
5th day ..... 7290 birds
The migration route as seen from that point was not fixed, but varied depending on the cloud formation: sometimes on the Nilgiri side, sometimes on the Dhampus side and sometimes straight overhead; but regardless, after 10 a.m. when a southerly wind started to blow, and clouds accompanied by updrafts developed, the migration of the cranes always started. When the cranes reached the narrowest part of the Kali Gandaki gorge upstream from Tukuche, the cranes were hit by the strong southerly wind and disbanded their formation, then, yelling the demoiselle crane’s characteristic ‘karankurun, karankuru’ call to each other, spiralled upward on the rising air current. (Note: It was reported that in the observations at P-29, when the cranes were in small groups by themselves with no other birds around, they did not call to each other, but remained strangely silent as they spiralled upward.)
We confirmed that when the cranes gain enough height to clear the Himalayan ridges, they re-form into their V-shaped phalanx formation and resume their southward flight.
The cranes which we observed were clearly identifiable as demoiselle cranes. Their call was clearly the demoiselle crane’s characteristic call. Both the first and second rows of feathers along the leading edges of their wings were solid black, and they were solid black from the throat to the breast. As far as we could tell, their were no cranes of other species mixed in with them.
Since our observing location was on the trail to Dhaulagiri base camp, we met climbers who descended for relief from the altitude and were able to keep posted on climbing activity on the mountain. On 6 October, the day after the day on which we observed the greatest number of cranes, an expedition from the Bernina Alpine Club of Yokohama succeeded in summitting Dhaulagiri. It was clear that at least in that particular area there is a clear correlation between the periods of best weather for mountain climbing and bird migration, confirming my own earlier hypothesis.
During the first week of October we counted a total of 14,500 cranes; considering that we probably were not able to count all of the birds that passed through the area we estimate that the migration involved more than 20,000 cranes. We travelled to Kagbeni to see if there were any cranes that failed to cross the mountains and descended to the river, then, on the return, crossed Thorong Pass, descended to the Marsyangdi river and returned to Kathmandu.
(6) The migration route of demoiselle cranes observed by satellite tracking :
From about the beginning of 1990, the Research Centre of the Wild Bird Society of Japan has been interested in using artificial satellites to track bird migration routes. This work uses the technologically advanced ARGOS system. Signals transmitted from a small transmitter are received by an American NOAA meteorological satellite in low altitude orbit, then relayed from a ground relay station to a satellite information centre in France where the data are analysed to give the path followed by the transmitter. NTT Wireless Systems Laboratories has been cooperating in the operation of this system.
Article 1 (N. Shigeta)
1. Demoiselle Cranes flying across Nilgiri.
Article 1 (N. Shigeta)
2. Migrating Demoiselle Cranes in the Kali Gandki valley.
Article 1 (N. Shigeta)
3. Formation of Demoiselle Cranes.
The WBSJ Research Centre has been attaching very small Platform Transmitter Terminals (PTTs) developed by Toyo Communication Equipment Co., Ltd., part of the NEC Corporation group of companies, to the backs of birds starting with small swans in 1991 and then moved into satellite tracking of larger birds such as cranes. The first crane study was of cranes which winter in Japan on their migration flights to and from their breeding sites in the Daursky Nature Reserve and the Khingansky Nature Reserve in Russia. The second study was of Siberian cranes on their migration flights between Yakutsk and Poyang Lake in China, followed by a study of red crowned cranes between their wintering and breeding grounds. In 1995, attention turned to the migration route of demoiselle cranes which was attracting attention through observations by Himalayan climbing expeditions.
I personally cooperated with NHK to some extent but was not otherwise directly involved in these surveys, but since I have a long - standing involvement with Himalayan climbing, I decided to receive information from people who were involved in the surveys and present it to the public. I thank those individuals who cooperated.
Now I would like to present some interesting results from the surveys of cranes crossing the Himalaya.
Three locations were selected for attaching the transmitters for these surveys: the Daursky Nature Reserve, Russia, for Route A;
Hovt, Mongolia, for Route B; and Kopa, Kazakhstan, for Route C.
Route A : To three of the cranes PTTs (transmitters) were attached at Darsky from 22 to 27 July. Of these, 3 birds started their southward journey about 23 September. It is confirmed that they travelled south as far as the Yellow river; but contact with the last bird was lost at QinghaiHu on 7 October. Since this route crosses the central section of the Nepal Himalaya, it is unfortunate that contact with these birds was lost. It is believed that the cause of the trouble with the transmitters is that the summer time temperature in the Daursky Nature Reserve, which is the birds’ breeding area, exceeded 40 degrees C, which is out of the transmitters’ design range.
Route B : Three of the cranes to which PTTs were attached at Hovd from 26 to 30 August were tracked. They started their southward journey in mid-September. On their way they rested at Barkol Hu (lake) for 10 days to 2 weeks, starting 16 to 23 September and ending 1 to 3 October. Then they headed south along the eastern edge of the Taklimakan Shamo (desert), crossed over the Himalaya (near the Garhwal Himalaya west of Dhaulagiri) on 7, 8 and 9 October, respectively, and finally arrived at their wintering area, Ajmer in Rajasthan, India, 10 to 13 October.
Route C : One of the cranes to which PTTs were attached at Kopa on 6 July was tracked. It started its southward journey sometime between 18 and 25 August. It detoured around the Tien Shan and the Karakoram, arriving in Pakistan on 28 August, and then proceeded to its wintering ground in Gujarat, India, on 28 September.
The Migration Route of Demoiselle Cranes -- through the Tibet and the Himalaya
(Map by Michiko Shingehara)
Thus, it was determined by direct tracking that 4 demoiselle cranes succeeded in arriving at their wintering grounds. However, the northward routes followed in spring have yet to be determined. We are anxiously awaiting a satellite tracking study to determine those routes.
(7) Some thoughts on the spring migration of demoiselle cranes : The location and timing of the fall migration routes of demoiselle cranes across the Himalaya are, as discussed above, now largely known, thanks to observations by mountaineering expeditions and satellite tracking; but the timing and routes of the northward migration to breeding grounds in spring remain complete mysteries.
In their book Birds of Nepal (1976), R.L. Fleming Sr., R.L. Fleming Jr. and L.S. Bangdel quoted the opinion of D. Proud, who speculated that the northward migration takes place in April and May. Norman Hardie, in his book The Highest Nepal, states, based on observations in Solu - Khumbu well to the east of the southward migration route, ‘Early in April countless honking geese can be seen in V-formation, flying north in the warm weather, bound for Mongolia and Siberia.’ So perhaps the birds migrate at this time at extremely high altitude, unknown to us, since in that season climbers are usually still at low altitude. But the evidence for this is still inconclusive.
Meanwhile, the following paragraph appears in Cranes of the World by Paul A. Johnsgard (1983). ‘Little else is known of the migrations of the eastern half of the population. The fall migrants regularly appear over Kohat in northwestern Pakistan in late August, while their earliest reported arrival date in Mysore, India, is December 20. Their latest spring departure there is March 5 (Ali and Ripley, 1969). In Tadzhikistan spring migrants have been seen during the first half of April, on the lower Syr Darya during the second third of April, and in the vicinity of the Aral Sea at the end of April. In the Altai Mountains they arrive from mid-April to the first part of May, and in northern Mongolia between late April and early May (Dementiev and Gladkov, 1968).’
Since there are 200,000 demoiselle cranes (some estimates go as high as 1,000,000) that migrate to India from the vast Eurasian steppes, from the Black Sea to northeastern China, Mongolia and Siberia, it is possible that they have to spread out over a wide area of India in order to find enough food. As hinted at by the report of Johnsgard quoted above, it is possible that these birds then detour west of the Great Himalaya and through Kazakhstan to reach their breeding areas in Mongolia and Siberia.
This suggestion agrees with the only satellite tracking data obtained so far in spring, by Ms. Nagendran and coworkers, who tracked 3 common cranes to which PTTs had been attached at Bharatpur in Keoladeo National Park. Perhaps this is a good route for the northward migration. It is to be hoped that a similar study of demoiselle cranes will be carried out in the near future. If it turns out that they cross over the Himalaya, then perhaps it will become possible to use their crossing to predict when the best climbing weather will occur.
(8) The importance of protecting cranes, and problems in protecting them : Cranes are a kind of barometer of wetland ecology. This is because cranes require wide breeding grounds and also wide wintering grounds. When wetlands are dried up by the use of the land as paddies for agriculture and by industrial developments that require a great deal of space, The number of cranes inevitably decreases. Conversely, a decrease in the number of cranes reflects change in the wetland environment, and serves as a barometer of the progress of development.
From this point of view, among the 14 or 15 species of cranes in the world, 4 species, the Siberian crane (Grus leucogeranus), the Whooping Crane (Grus americana), the Black Necked Crane (Grus nigricollis) and the Red Crowned crane (Grus japonensis), have been the subject of calls for protection from around the world since about 1983. Fortunately the red crowned crane of Japan has recovered, but the Siberian cranes that migrate to India from the Ob River basin had declined to only 1 bird by 1996.
India is a predominantly Hindu country where living things are revered. The Sarus crane has been completely protected ever since the Hindu holy book the Rig Veda declared it to be a holy bird that brings happiness. The Bombay Natural History Society (BNHS), which has a long history and proud tradition, has put great emphasis on research on and protection of birds since before World War II. It is believed that birds undertake the long migration across the Himalaya and winter in India because for them it is a paradise.
However, as was discussed in Section 4, there is a problem of attrition of birds during the migration, which was raised at the conference at Keoladeo Ghana in February 1983. Apparently some birds, although only a few, are being hunted as they pass over the Kali Gandaki. An article titled ‘Crane Dance on the Blink’ which appeared in the Friday Supplement of The Rising Nepal on 10 August, 1984 called for the birds’ protection. But protecting them during a long migration requires international cooperation.
(9) Reminiscences of 40 years and remaining problems : The 40 years since I first became interested in the cranes crossing the Himalaya have gone by in a flash. Here I would like to briefly summarise the principal developments of each decade.
From a report on ‘cranes crossing the Himalaya’ brought back by a Himalayan climbing expedition, it was inferred that they must fly in the opposite direction, from south to north, in the pre-monsoon season, but it was not possible to verify this in the 1960s.
From one photograph taken on P-29 in the fall of 1970, it was discovered that cranes serve as a harbinger of good weather; in October 1976 an expedition used the cranes to time an assault on Manaslu, and succeeded in climbing the mountain. This produced an increased interest in cranes among Japanese mountaineering expeditions, leading to a number of reports on crane sightings. This information combined with analysis of weather maps indicated that the there is a significant correlation between the date of the cranes’ flights and the dates on which summit assaults will be possible in the post-monsoon season, at least in the Annapurna, Dhaulagiri and Manaslu groups of peaks along the Kali Gandaki in central Nepal.
This decade saw the successful motion picture filming of the cranes. Some expeditions set out from Japan for the specific purpose of filming the cranes. The records of movements and bird calls which were obtained made it possible to clarify the way they gain altitude and the flight mechanism.
At the same time, as a result of studies, it was found that crane migration is a barometer of the health of wetlands and demonstrated the importance of suitable sites for resting at intermediate points on the migration path.
Since 1991, the Wild Bird Society of Japan and the Yomiuri Shimbun Sha have cooperated in satellite tracking studies. The data have attracted considerable attention, for example at the National Diet Symposium commemorating the Ramsar Treaty in June 1993, resulting in international awareness of the link between crane migration and wetland protection. The protection of intermediate points along migration paths was taken up at the next of the series of conferences in Australia in 1996. Meanwhile, studies of crane migration across the Himalaya are entering a new era with the success of satellite tracking of demoiselle cranes.
The main task now facing us is satellite tracking of demoiselle cranes as they cross the Himalaya during their springtime migration northward to their breeding grounds. If the route(s) and timing can be clarified, then perhaps we Himalayan climbers can also learn something from the cranes.
A study of migration of Demoiselle Cranes across the Himalaya and prediction of weather patterns based on the such migration.