Finnish Museum of Natural History
Young female Osprey M-48905 "Mirja"
On 2 July 2002 in Hauho, Ilmoila, in Häme, Tero Niskanen ringed three Osprey fledglings. The youngest, M-48905, was recaptured at the nest on 31 August, when she was observed to be a female weighing 1810 g, and she was named "Mirja". At this time, Mirja had already been fully fledged for over three weeks. She was fitted with a solar-powered transmitter weighing 30 g (manufactured by Microwave).
Autumn migration 2002
Unfortunately, it is not known exactly when Mirja left her nest. The last reading from the nest was received on the evening of 8 September. The following readings were received on 11 November and showed that Mirja had started her migration and had left Latvia behind her as she was flying over Poland near Krakow at a speed of 63 km/h (544 km/8 h 42 min). The following readings came from the southern border of Hungary (12 Sept), northern Croatia (14 Sept), the Montenegro coastline (15 Sept) and NW Greece (16 Sept). The journey from Hauho to Greece (2590 km) was traversed in (or less than ?) seven days, i.e. with the average speed of at least 370 km/24 h. After her flying start, Mirja filled up for five and a half weeks (16 Sept - 24 Oct) in North-West Greece, on the fertile plain of Arta, criss-crossed with canals, lying between the Pindos mountain range and the Ionian Sea.
Mirja continued her migration on 26 October, at the latest. The first unclear reading was received on 27 October at 02.09 from the sea to the South of Crete, and at 08.33 Mirja had reached the coast of Egypt. Next day, she flew on over Libya. She flew over the border of Chad on 31 October, and Sahara was left behind 24 hours later. Mirja covered the 2177 kilometres between the coast of Egypt and the south end of the Sahara desert in five and a half days, making an average speed of 396 km/24 h.
Having flown over Chad from North to South, Mirja crossed the border to Cameroon on 7 November. After apparently following the Djerem River, she ended up at the Tibati reservoir. Mirja's migration from Hauho to Tibati in Cameroon totalled 6842 km. If Mirja had flown the straightest way possible, it would have been 6186 km, so her first autumn migration included 10% extra travel, due to 'novice uncertainty'. Mirja's journey to Tibati took c. 60 days, of which 22 were actual travelling days. The total speed was 114 km/24 h. If only the travelling days are taken into account, her average speed was as much as 311 km/24 h.
Mirja spent mid-winter (8 Nov 2002 - 2 Feb 2003) at the Tibati reservoir (6.4°N/12.7°E) and stayed in an area of c. 500 km². On the 3rd of February, Mirja continued 226 km SW from Tibati, to the banks of the Moinum river.
Spring migration 2003
Since Mirja was born in 2002, she did not migrate.
Summer and autumn 2003
Mirja has made herself at home at the Moinum river for practically the whole summer and autumn. She visited her first wintering area at the Tibati reservoir on 15 July – 1 August, but since 3 August, all the readings have been coming from around the Moinum again, about one hundred kilometres to the north of the spring readings.
Mirja stayed upriver of the Moinum for four and a half months (3 Sept - 23 Dec). For Christmas Mirja returned to the area where she spent spring 2003, and stayed until April Fool's Day.
During the period 8 Nov 2002 – 1 Apr 2004, there have been a total of 498 readings on Mirja with a nominal accuracy of less than one kilometre. On the basis of these readings, we can estimate that Mirja has been moving about an area of 14 249 km2 in all during this time, which equals the Pirkanmaa province in Finland. As has been described, the readings are concentrated to three areas. If we count in 95% of the observations, we get the following extents of Mirja's three home ranges: The Tibati reservoir 326 km2, the lower reaches of the Moinum 459 km2 and the upper reaches of the same river 1314 km2.
Mirja left the Moinum river on 2 April 2004 for her first spring migration in a north-north-easterly direction. In the early morning of 3 Apr the satellite spotted Mirja 207 km from the Moinum. At noon on 4 Apr, Mirja flew across the Lac de Lagdon reservoir, and by the evening, she had covered 613 km. The following day saw Mirja in Chad, east of Lake Chad, and in the morning of 7 Apr at the ultimate point of her 'spring migration,' 70 km north of the northern end of Lake Chad. So far, Mirja had proceeded swiftly: covering 1,277 km in five days, i.e. 255 km per day.
There ended the determination of her migration. First, Mirja made a loop of 750 km to the south-east, and then over the east end of Lake Chad to the Chari river, close to the capital, N'Djamena, for the night of 16-17 Apr. Then she flew further south-east, and since 19 Apr she has stayed by the Chari river, 294 km from N’Djamena. At this point, Mirja had flown 2,533 km in 18 days, averaging 140 km/day.
On the evening of 25 April, the satellite still showed Mirja at the Chari river. The following reading, on 28 April, told us that Mirja had flown 716 km to the northeast in two days. Her migration continued, first along the border between Chad and Sudan, and then that between Libya and Egypt (2-5 May) towards the coast of the Mediterranean. After crossing the Sahara, Mirja set out over the Mediterranean immediately. On 5 May at 9.17 she was 19 km from the coast of Cyrenaica, on the following day (6 May) at 11.08, she was 71 km east-southeast of Athens and at 14.53, she was on the northwest coast of Turkey, only some ten kilometres east of legendary Troy. It took her 11 days to fly from the Chari river to the vicinity of Troy, covering 3,784 km, which means that she averaged a breakneck speed of 344 km per day!
The following reading, which was not received until a week later (13 May), showed that Mirja had continued 195 km due east from Troy, towards Ankara, which was then 354 km away. Then Mirja changed her course radically again, and travelled 366 km north-west, crossing the Sea of Marmara (16 May) and the European part of Turkey, ending up in Bulgaria, in the Khaskovo region 190 km south-east of Sofia (17 May). During the following week, Mirja flew 364 km nearly due north. On 23 May, the satellite found her in Romania, at the foot of the Transylvanian Alps, 125 km north-west of Bukarest. From there, Mirja headed to Bihor in western Romania, close to the Hungarian border, 282 km northwest of the previous day’s reading.
After this, Mirja headed straight towards Finland: she spent the night of 25-26 May in the Ukraine, 12 km from the landmark where the borders of the Ukraine, Slovakia and Poland meet, and on 27 May – 1 June she travelled through the east of Poland, spending the night of 2-3 June in Estonia, near the spa town of Pärnu. The next night, Mirja was already in Uurainen in mid-Finland, about 30 km northwest of the town of Jyväskylä.
In all, Mirja’s migration from Cameroon to Uurainen took 62 days, covering a total of 9,286 km. As mentioned before, it took Mirja 60 days, covering ‘only’ 6,842 km, to migrate from Hauho to Cameroon in the autumn of 2002. The shortest way from Cameroon to Hauho or Uurainen is about 6200-6300 km.
Two-year-old Mirja’s visit to Finland only lasted four days. After spending the night in Uurainen, she flew northwest to Perho by the Perhojoki river, and next day (5 June) she flew 131 km westwards, to the coast at Vaasa. After that, Mirja’s autumn migration for 2004 started!
Summer and autumn 2004
Mirja listened to the waves in the Gulf of Finland overnight on 6-7 June, by Orslandet in the Inkoo archipelago. Next morning (8 June), Mirja was in Estonia, 19 km south of Pärnu, whence she continued along the coast of the Gulf of Riga, ending up in Riga (11 June).
On 15 June, Mirja was still in Riga, and on 18 June the next reading arrived from Latvia, from the banks of the Daugava river, 58 km east of Daugavpils. One day later (19 June), Mirja was in Lithuania, only 15 km from central Vilnius, and on 22 June she was in Belarus, 136 km north-northeast of the city of Brest. The same day, Mirja arrived in the sparsely-inhabited Polesye marshlands, covering some 100,000 km², where she stayed fishing at the waters of Belarus, Poland and the Ukraine until the end of July.
On the 1st of August, we received a very faint signal from Serbia, indicating that Mirja had continued her journey to the south. After that, for over a month, Mirja stayed in the plain of Árta in north-western Greece, in exactly the same area where she stayed for five and a half weeks during her first autumn migration in 2002.
Due to the malfunction of the transmitter, we do not know exactly how long Mirja availed herself of the fruits of Árta this time. On the early morning of 17 September, Mirja was still in Greece, at the southwest point of the Peloponnese peninsula. The following morning, the readings came from the Libyan coast, then her journey continued across Libya (18-21 Sept) and west of the Tibesti mountains near the east border of Niger (22-25 Sept) towards Nigeria.
In the early evening of 26 September, the first signal came from north-east Nigeria. At that time, Mirja was 187 kilometres south-west of the southern tip of Lake Chad. Then her journey continued 100 km to the south-southwest (28 Sept), then 230 km to the north-west and then 450 km to the west-southwest (29 Sept – 6 oct). Since the 6th, Mirja has remained in a narrow area, 220 km due north of the confluence of the Niger and Bénoué rivers, at the upper course of the Kaduna, a tributary to the Niger. This area is about 720 km north-west of the Tibati reservoir, which was one of Mirja’s main bases in Cameroon during 8 November 2002 – 1 April 2004, the other being the Moinum river.
The white symbols and dotted line on the map show that Mirja’s migration route from the Polesian marshes to the south of the Tropic of Cancer is based on unclear but quite logically progressing readings. In spite of the inaccuracies, it is clear that Mirja crossed the Sahara along a completely new route in autumn 2004, on an average flying some 650-700 km west of her route of autumn 2002.
After spending exactly three weeks (6-27 October) by the Kaduna river, Mirja continued to look for her final wintering area. First she wound her way during five days, covering a distance of 876 km to the west. On 3 November, Mirja arrived at the Oli river in Ghana, at a place 15 km north of the northern bay of Lake Volta. There she turned around and returned to Benin for a week (4-12 November).
After that, she headed the 700 km back to Nigeria, to the fishing at Benue, the western branch of the Niger (17 Nov). Having flown 700 km again, Mirja arrived back in Benin on 21 November. She stayed at the upper course of the Ouémé river for some five weeks.
On the morning of 27 December, Mirja was still at the Ouémé river. The following day, the satellite showed that Mirja was back in Nigeria, rapidly flying to the southwest. On that night (28 Dec), the readings came from the Oshun river, 78 km east-northeast of Lagos and only 28 km from the coast of the Gulf of Guinea.
Mirja did not stay at the coast, though, but flew on, first 195 km east (29 Dec), then 179 km northwest (30 Dec) and 262 km west-northwest (31 Dec). On New Year’s Day (1 Jan 2005), Mirja was back at the Ouémé river in Benin. This reading also came from the bank of Ouémé, from a spot 51 km south from where Mirja started out on 27 December, and 23 km north of where she spent the night 1-2 Dec before moving on to Ghana.
The total distance of Mirja’s roundtrip to the coast on 27 Dec – 1 Jan was 980 km. In other words, during five days around the turn of the year, Mirja checked out the landscapes of Benin and Nigeria at a speed of 196 km per day.
After fishing at the Ouéme river for three weeks, Mirja headed back east on 25 January. Three days later, she reached the western part of the Adamawa plateau and crossed the border to Cameroon on 1 February. Then Mirja changed her direction to the southeast and finally (on 4 Feb) – after ten days and 1,037 kilometres – arrived at her wintering area at the Moinum river, from where she had set out for her trip to Finland ten months earlier. It seems clear that both of Mirja’s earlier trips several hundred kilometres to the east were attempts to fix her deviation too far west off course when crossing the Mediterranean and Sahara.
This time Mirja stayed less than two months at her ‘real’ or ‘final’ wintering area, because the reading from 31 March shows that Mirja had left the Moinum river and flown due north. The satellite first discovered Mirja at 14 o’clock, flying along the north side of the Faro Reserve by the border between Nigeria and Cameroon, 342 km from River Moinum. Her flight continued to the huge reservoir (Lac de Lagdo) built into River Benue where Mirja had visited before on 4 April 2004. By April Fool’s Day, Mirja had crossed the border to Chad and had covered 731 kilometres by then.
On the morning of 3 April, Mirja crossed the Chari river at the same point where she had refuelled in April 2004 before setting off to cross the Sahara. On the night of 6 April, we received a very clear reading that showed that Mirja had purposefully proceeded 1,509 km due north during six days. Then her purposefulness ended – exactly at the same time as the previous year! On the following night (7 Apr), the satellite showed that Mirja had turned tail and gone 190 km back to the area where she had been on 3 April!
Then she changed her course again: On 8 April, Mirja flew 219 km due east, and on 9 April, 184 km to the northeast. At noon on 10 April, Mirja was only 80 km off her course of spring 2004, which ran due north along the border between Chad and Darfur in Sudan. On the 11 th of April, Mirja surveyed the breathtaking views of the Ennedi plateau, famous for its imposing rock arches and for the last crocodiles to be found in the Sahara. (The following webpages show some magnificent photographs from Ennedi: http://www.naturalarches.org/gallery-ChadPortfolio.htm http://www.marches-lointaines.com/ennedi/ennedi-e.htm )
If there are crocodiles in the canyons of Ennedi, there may be some fish to refuel Mirja's energy supply.
At this stage, Mirja's spring migration has lasted 13 days, and including all the detours, she has flown c. 2,500 km. If Mirja had taken the shortest route from River Moinum to Ennedi, she would only have covered 1,836 km.
Mirja spent the night between 13 and 14 April in Chad, at the Aouzou strip where there is assumed to be a great deal of oil and uranium. Chad and Libya fought a war over the area in the 1970s and 80s. The following night Mirja spent in Libya, 20 km north of the Tropic of Cancer, and 120 km west of the Egyptian border. On the night between 15 and 16 April, Mirja spent at least six hours (21:00-03:09) at the southern edge of the nearly 500-kilometre long Calansho Sand Sea. At 07:39 on the morning of the 17th, Mirja was already 615 km from the previous reading and only 63 km from the coast of the Mediterranean! Judging from the scattered meteorological information, a strong southern wind may have helped Mirja on her way.
Mirja’s voyage from Cameroon to the coast of the Mediterranean took 18 days, covering 4,080 km, making an average speed of 255 km/d. The straightest route would have covered 3,220 km. This means that Mirja flew an ‘extra’ 780 km, of which 400 km were spent when she doubled back. The straightest way from the coast of Libya to Häme is c. 3,200 km, so at this stage, Mirja was about halfway.
After reaching the coast, Mirja immediately continued across the sea, and on the afternoon of the 17th she was 115 km from the coast of Crete. According to Associated Press, a sandstorm out of Africa made it necessary to sloce down the airports on Crete and Rhodes on the evening of the 17th, so Mirja was flying in fairly extreme circumstances. Unfortunately the readings of the following day (18 Apr) were very unclear and somewhat conflicting. However, they showed that Mirja had drifted east, onto Rhodes waters – apparently she was carried by the storm.
On the night between the 19th and 20th, the satellite picked out Mirja on the east coast of Turkey. She was 345 km from Rhodes, 54 km north of Izmir, i.e. the city of Smyrna that recently celebrated its 5000 years of existence, and 127 km south-southeast of Troy. Mirja stayed near Troy on 5 June 2004.
On the afternoon of 21 April, Mirja had already crossed the Dardanelles into Europe. She was still in Turkey, 170 km due west of Istanbul and some 50 km from the Greece border.
The following reading came on 24 April and was very unclear as to location, but it showed that Mirja had passed the northeast part of Greece and flown over the border to Bulgaria. In the evening of 25 April, Mirja was in an area 106 km almost due east of Sofia. After crossing the Dardanelles, Mirja had progressed 260 km to the northwest in four days, averaging only 65 km per day. By heading to the northwest, Mirja may have been correcting her course after being thrown off it and flying too far east due to the sandstorm. If Mirja had flown due north after arriving at the coast of Libya, she would have arrived in the same area where the satellite discovered her on 25 April.Mirja’s trip from Libya to Bulgaria totalled 1,400 km because of the sandstorm. The straightest route would have covered 1,110 km.
After noon on 28 April, we finally received a seemingly reliable, though still very unclear reading. It showed that Mirja is still in Bulgaria, 30 km southwest of the city of Pleven, and 50 km due south of the Danube or the border of Romania. This means that, during the last three days, Mirja has only progressed 80 km to the north-northwest.
ARGOS did not relay the following signal until the 11 th . According to this reading, Mirja had been in Belorussia on the morning of 9 May, at the upper course of the Neman river 132 km northwest of Minsk. There are several rivers and small lakes in the area, and probably nesting ospreys as well. After the reading from a week before, Mirja had travelled 744 km to the north ‘in stealth mode', unnoticed by the satellite.
Three days later (12 May), Mirja was on the east side of the Lake Peipus in Russian territory, 66 km northeast of Pskov, 126 km due east of Tartu and 130 km from the coast of the Gulf of Finland. She had traversed 417 km since the previous reading; the same distance (410 km) remained to her place of birth, Hauho.
Without prejudice, Mirja crossed the border into Finland a little before noon on Friday the 13 th . At 10.40, we had had a reading from Russia, near Reboly in Karelia, 18 km due west of Vyborg. At 15.25, Mirja had already reached Savitaipale on the west shores of Saimaa, 33 km northeast of Lappeenranta.
Mirja's migration from Cameroon to Savitaipale took 44 days, covering 7,629 kilometres, so on an average, Mirja flew 173 km per 24 hours. If Mirja had taken the shortest route, she have covered 6,344 km, i.e. 1,285 km (17 %) of her trip was ‘superfluous'.
Mirja's first autumn migration from Finland to Cameroon in 2002 took 60 days. At that time, she covered 6,842 km, of which 10 % was ‘superfluous'. Her return trip to Finland in spring 2004 took 62 days, covering as much as 9,286 km with her flying back and forth.
Comparing Mirja's spring migration with that of ‘Victoria' from Sierra Leone to Pälkäne in spring 2003, we can observe the following. Victoria set out for her migration at the same time as Mirja (30 March), but had already reached her nest from the previous year on 2 May, i.e. 11 days earlier than Mirja arrived at Savitaipale. The direct route from Sierra Leone to Victoria's nest was 6,592 km, slightly more than Mirja's from Cameroon to Savitaipale. Victoria covered a total of 7,120 km with only 528 km (7 %) ‘superfluous'. Victoria averaged 215 km per 24 hours. Victoria nested successfully and produced one fledgling in summer 2003.
On 14 May, Mirja was still at Saimaa, c. 200 km due east of her birthplace in Hauho.. This time the reading came from Puumala on the east shore of Saimaa, 29 km northeast of the reading from the previous day.
The next readings from Mirja did not come until the morning of the 24th. Then they came from Russia, from Pyhäjärvi in Impilahti 16 km to the northeast of the north-eastern tip of Lake Ladoga. At noon the satellite discovered Mirja on the Finnish side of the border, in Kiihtelysvaara in North Karelia, 118 km to the northwest of the morning’s readings. Twenty-four hours later (25 May), we had a fairly strong signal from Savo: from Nilsiä near the border to Juankoski to be exact. It showed that Mirja had wandered a further 124 km to the northwest.
It is possible that Mirja continued to the northwest as far as the coast of the Gulf of Bothnia, because on 27 May we received a very poor reading from the archipelago of Haukipudas. However, it is more likely that this reading was false, since we had several readings of Mirja only 24 hours later (28 May) from Kuhmo near the eastern border. Late in the evening of the 29th, we received the most exact reading (fault margin less than 350 metres) on Mirja in a long time. At that time, Mirja was in the area of the city of Joensuu, 21 km northwest of its centre, near the border to Polvijärvi.
On the 31st of May at 13.30, we finally received a report of a first sighting of Mirja. At Ahonkylä in Liperi, professional ornithologist Harri Kontkianen, who studies bird waterlands, saw an osprey with a 10-centimetre antenna protruding from its back. The sighting area is 20 kilometres from the site of the very exact reading received on 29 May. This individual must be Mirja, since only two other Finnish ospreys (Sarsa and Laho) still have their transmitters strapped to their backs. Both have been sighted numerous times during this spring near their nesting areas in Häme.
On the 1st of June, the satellite confirmed that Mirja had taken a fancy to the landscapes in North Karelia. We received a fairly accurate reading from the eastern coast of the northwest bay of the Hyötiäinen lake in Polvijärvi.
Some fairly unclear readings received during the first half of June have shown that Mirja has been travelling over a wide area in North Karelia, and possibly also visited the Russian side of the border.
During the latter half of June and the first week of July, Mirja wandered around North Karelia, the shores of Lake Ladoga, and as far as Ingria west of St Petersburg. During the latter half of July, only a few very unclear signals were received, all from the vicinity of Lake Ladoga.
According to some very unclear signals, Mirja was still at Punkaharju on the night of the 24th, and in the northern archipelago of Lake Ladoga on 25-28 July. On the morning of 4 August, a clear signal was finally received from Mirja, showing she had started her migration to the south. At that time, Mirja was in Russia, 65 kilometres due north of the city of Pskov, and 45 km east of the eastern shores of Lake Peipus. At noon the following day (5 Aug), the satellite discovered Mirja in northern Lithuania, 45 km from the border to Latvia and 118 km north of Vilnius. A week later, a signal was received from Belarus, 300 km from the previous signal. On the 15th, Mirja had crossed the border to the Ukraine and returned to the wide-spread Polesye marshes, where she stayed for nearly five weeks last summer (22 June – 27 July 2004).
The following reading was not received until exactly two weeks later (29 Aug). It showed that Mirja was in the Pindus Mountains in the northwest of Greece at that time, c. 40 kilometres northeast of the plains of Arta, where Mirja had stayed for over a month both in autumn 2002 and 2004. Since the reading was very unclear, it is very possible that Mirja was actually at the good hunting grounds she knew around Arta, rather than up in the mountains nearby.
After this, there were no signals from Mirja for nearly a month. It was not until the afternoon of 26 September that an extremely faint signal gave reason to believe that Mirja was crossing the Mediterranean and arriving at the coast of Libya. Three days later (29 Sept) the suspicion was backed up by another faint signal indicating that Mirja had started to cross the Sahara and left the coast 525 kilometres behind her. One day later (30 Sept), the satellite managed to capture the first clear signal from Mirja’s transmitter. It showed that Mirja was currently at the Tropic of Cancer.
This time, Mirja flew straight over the Tibesti mountains, which rise to a height of over three kilometres, and she also spent the night between 1 and 2 October there. The relentless radiation of the desert had finally revitalised the solar panel of the transmitter, because we received three very clear signals from Tibesti; the accuracy of one of the signals was 350 metres, of the other two, one kilometre. The following day (3 Oct), the satellite kept track of Mirja for over seven hours, during which time she progressed 329 km and crossed over from Chad to Niger.
On the afternoon of 4 October, we received a very clear signal from Mirja at the border between Niger and Nigeria, 40 kilometres west of the middle point of Lake Chad. Mirja spent the night between 5 and 6 October just a few kilometres from where she rested during the night between 26 and 27 September last year. As the morning dawned on 7 October, Mirja was at the edge of the mighty Bénoué river that runs into the Niger. She was 100 km west of the northwest border of Cameroon and only 430 km from her familiar wintering place by the Moinum river. Later the same day, Mirja crossed the border to Cameroon and stayed the night by a tributary to the Bénoué river, which has it source on the north face of the Adamawa mountain.
After flying over the Adamawa mountain (8 Oct), Mirja spent the night at the banks of a river running into the Tibati reservoir, only 47 kilometres from the area at its west end where she settled down for the winter in 2002. During the following day (9 Oct), Mirja slowly continued southwest and ended up at the familiar upper course of the Moinum river. On the evening of the 11th of October, the satellite disclosed that Mirja was in the exact same area where she had stayed from the beginning of August until Christmas in autumn 2003.
The European leg of Mirja’s third autumn migration remained somewhat unclear, due to transmitter problems. However, we were able to roughly map the migration. Mirja’s trip from the north shores of Lake Ladoga to Cameroon took 65-70 days in all, and she covered 6,570 km. If Mirja had taken the shortest possible route, the trip would have been 6,359 km. In other words, she seems to have covered only some 200 km, or a little over 3 %, ’extra’ ground. In reality, the ‘extra’ part was a little longer, since there were no signals to show the possible detours during Mirja’s trip from Polesia to Greece.
Mirja’s first migration in autumn 2002 was a young bird’s flight into the unknown. In the autumn of 2004 (29 August 2004), against all expectations, Mirja strayed from the border area between Cameroon and Nigeria towards the west, and during late autumn and the beginning of winter, she roamed in Nigeria, Benin, and as far as Ghana. It was not until the beginning of February 2005 that she ended up in the same area in Cameroon where she had spent the two previous winters. Now, in autumn 2005, when she has one year more of experience under the belt, Mirja travelled purposefully all the way to the fishing grounds in Cameroon.
Mirja spent all winter, i.e. nearly five months between 11 th October and 6 th March, at her familiar surroundings at River Moinum in Cameroon .
On the morning of 6 th March, the satellite still located Mirja at the Moinum. By the evening of the following day, she had flown 192 kilometres north-northeast toward the northern side of the Tibati reservoir. On the morning of the 9 th , Mirja was still in Cameroon , some 100 kilometres south of Lac de Lagdo, but two days later she was already in Chad , 594 km from her starting point. The readings from the morning of 13 March show that Mirja was flying north on the north side of River Chari, some 160 km southeast of N'Djamena, the capital of Chad. The exact readings received on 14 th and 16 th March showed that Mirja had headed straight north until the customary ‘set-back' of every spring set in on the 18 th . If the ARGOS accuracy classes 2 (<350 m) and 3 (<150 m) are true, Mirja had returned 229 km due south in two days!
Her return loop remained short this time, though, as the clear reading received on the evening of the 21 st showed that she had flown 663 km northwest in the following three days. One day later, in the early morning of the 23 rd , the satellite discovered Mirja on the northern slopes of Tibesti, 301 km from the previous reading. At this point, Mirja had been travelling for 16 days, and had covered a total of 2,584 km including her return loop. She had 975 km left to reach the shores of the Mediterranean as the crow flies.
The following readings (24-27 March) were very unclear, but they followed each other in a straight line across the Libyan desert to the east side of the Gulf of Sidra. In the early morning of the 27th, a reading showed Mirja spending the night on the southern slopes of the Akhdar mountains, 115 km east of the coastal town of Benghazi, but according to the following reading seven hours later (at 11.44 local time), she was at sea, 53 km west-northwest of Benghazi. Since both the readings from the 27th are very inaccurate, it is possible that the detour to the west-northwest shown on the map did not really happen. However, it is certain that Mirja arrived at the Mediterranean coast on 27 March, three weeks after she started her spring migration. If Mirja would be returning to her place of birth at Hauho, she would be about halfway now, measuring as the crow flies.
It took a total of 12 days before we received another reading from Mirja’s transmitter. According the coordinates – which were rather inaccurate again – received from the satellite, Mirja was in western Ukraine on 8th April at 12.48 local time, some 62 km east of the city of Lvov. She had covered circa 2,000 km as the crow flies from the waters of Benghazi, and she has 1,200 km left to reach Finland.
Three days later, on 11 April at 7.17 o’clock, we received the following reading, which was somewhat inaccurate again. It showed that Mirja was already at the border between Lithuania and Latvia, 127 km southeast of Riga. At 9.45 another inaccurate reading was received from Russia, 216 km northeast of the previous reading, and 126 km south-southeast of Pskov. It seems clear that Mirja did not take a route covering these two points, at least not both of them. In any case, Mirja only had some 400 km to go to reach Finland.
The readings of the following day (12 Apr) confirmed that Mirja was, in fact, in Russia. The latest reading came at 16.49 local time from 108 km southeast of Pskov and 293 km due south of St Petersburg. According to the inaccurate readings, Mirja proceeded only 92 km to the northeast from the morning of the 11 th to the afternoon of the 12 th. Does winter still hold Pskov in its grip, slowing down Mirja's progress?
During the following day and night, Mirja travelled 172 km northwards. The readings on Good Friday and Easter Saturday (14-15 Apr) were received from the small town of Luga, 105 km due southeast from Narva. During Easter (16 th – morning of 18 th ) the satellite picked out Mirja in Ingria, only 5 km from the coast of the Gulf of Finland, 42 km west of central St Petersburg and 26 km east of the Sosnovyj Bor nuclear plant. During the past week, Mirja has progressed very slowly, only covering a total of 360 km in that time.
At noon on 19 April, we received three fairly accurate readings. They all showed that Mirja was still in Ingria, 50 km southwest of her previous location, and 50 km northeast of the city of Narva. According to a very inaccurate reading received during the night between the 20th and 21st, Mirja was only 25 km from Narva and the Estonian border at that time. At this stage it looks like Mirja may find a nesting place and a mate in the osprey habitats of Ingria or Estonia.
Mirja left Ingria on 23 April after all. At 18.30 local time, we still received an accurate reading from 42 km east-northeast of Narva. A couple of hours later, an inaccurate reading showed that Mirja had moved on to a small lake in Kannas for the night. The following day, Mirja had flown 155 km northeast and, according to an accurate reading settled for the night barely two kilometres from the shores of Lake Ladoga.
On the morning of 30 April, according to an accurate reading from Mirja's sender, we were surprised to see she had returned to the region of Lake Vuoksa. The search for a mate and her own territory continues...
During the first third of May, the readings were centred on a strip of land 20 km long near Lake Ladoga, about 50 km southwest of Sortavala and 30 km north of Priozersk. According to one signal – which, according to Argos, was accurate (accuracy classification 1 i.e. less than 1 km) – Mirja had gone on a hunting expedition as far as Valamo on 8 May.
After tracking her over three years and eight months, Mirja’s transmitter fell silent. The last reading was received on 12 May 2006 at 13.07 local time from the shores of Rautalahti by the south corner of Sortavala, 15 kilometres south-southwest of the centre. We can only guess at the reason why the transmitter has not been heard from since. Maybe it just stopped functioning? It is also possible that the frayed attachments broke off – as they were designed to do – and the transmitter fell into Lake Ladoga . Be that as it may, Mirja’s transmitter will go down in history as the first in the world to follow the first few years of a young female osprey’s life.