Wednesday, August 14, 2013

The Steller’s Sea Eagle surveys in 2013

The Steller’s Sea Eagle surveys in 2013 

The Steller’s Sea Eagle work in 2013 consisted of our routine surveys in end of July and August (Irina Utekhina and Eugene Potapov).
            The surveys were carried out using traditional motor boat. In addition to the existing technique we continued to perfect the usage of the UAV (unmanned aerial vehicle) first applied in 2012. This year apparatus was more steady, lighter and most important, foldable. The enhanced stability made it to be launch-able from floating boat, which proved to be useful on several occasions during this season.
July-August trips.
In the end of July- beginning of August we made our regular surveys along the Kava and Chelomdja, along the coasts of the Magadan vicinity (Staritskogo Peninsula), Odyan (this year we streatched the surveys to the Taran cape of thus covering the entire northern portion of the Koni Penninsula) and Motykley Bay.
            The order of trips was repeating last year surveys. We started from the Kava-Chelomdja portion of the Reserve (July 27 – 30 July), then proceeded to the Motykley Bay and Talan island (31 July – 1 August), then to the Odyan Bay (6-8 August), and finally to the Staritskogo peninsula (9 August). As in the last year, the weather window gaps at the sea were the main constrains for this season, especially at the end of the season. In fact the the surveys we were haunted by the rain, which was a tail of the giant cyclone which severely flooded the Amur river in the Russian Far East.

The Kava-Chelomdja portion of the Magadan Nature Reserve.
The Kava Chelomdja portion of the Reserve had lower, than the last year, but still relatively good breeding success this year. We covered our usual study area (upstream to the upper chum spawning grounds at the Chelomdja (overnight at the Kheta ranger’s station), and expanded the survey 10 km upstream from the Ikremun ranger’s station on the Kava. As in the last year, both rivers had NO pink salmon run. I saw only 1 dead pink salmon during the entire trip. The bears were skinny and not numerous along the rivers, thanks to a good standing crop of the Siberian creepy pine on the mountain slopes. The coho salmon run was more or less successful, and the same was anticipated for the silver salmon run. As in the last year, there was no commercial salmon tickets issued this year, so the fishing camps on the river were idle.
There were no eagle chicks produced in the 5 occupied nests at the Kava river at all. However the residential pairs were present and were seen on the river.

Figure 1. Surveyed Kava (upper) and Chelomdja (lower) portion of the Magadan State Nature Reserve. Red patches show productive nests at the Chelomdja and Tauy rivers.
On the Chelomdja river the water, thanks to frequent rains was murky with lot of leaves, twigs and tree-trunks floating along the river. In total there were 3 chicks in 13 occupied territories on the Chelomdja River. One nest was at the confluence of the Kava and Chelomdja; the latter was traditionally listed as the Chelomdja nest. One nest/territory at the Chelomdja was new (at the confluence).
Due to turbid waters practically all eagles were sitting on shore/near pools at the river shallows, sometimes near log jams. Clearly they were trying to get at least some fish in such places.

An eagle sitting on a small log jam. Note murky water.

On the Tauy River between the Talon village and the ranger’s station there were 3 productive nests (one, one and 2 chicks), with two closest to the Talon having the distance 1 km between them. Previously we considered these nests belonging to one pair, which proved not to be the case. There were 4 occupied territories at the Tauy river.
As in the last year, the deployment of the drone (foldable this time) was quite a success. The drone has completely eliminated ‘doubtful’ nests where the contents were not easily observed from the ground. We have flown 3 missions which returned positive results (chick in the nest), and 5 missions resulting empty nests.

Flying a drone from the water in a confined channel.

View of the nest M19/109 at the Chelomdja river on 29 July 2013 from below the nest (top) and from the drone (bottom).

As in the last year we report practically no reaction of the eagles to the drone. However last year’s drone was equipped with ultrasonic height-measurement device, which might be audible to the birds. The recent model did not have such contraption, and therefore did not emit any noise apart of the propeller’s noise. On one occasion we did have a non-aggressive fly-by by a female at the time the drone was hovering by a nest with the chick (Figure 5). The female flew above the drone making alarming noise, and then disappeared in the woods across the river. The minimum distance between the drone and the bird was about 15 m, with the eagle being approximately 5 meters higher. After fly-by the chick laid down in the nest.

 Eagle fly-by moment. By the time I got the eagle in the view the drone was higher than the eagle.

Motykley trip.
            By the time we got to the Balagannoe, we had being constrained by cyclone system (Figure 6). There were continuous rain clouds both in the forecast and in reality. After spending a day in the Balagannoe, we decided to hit the Motykley bay area in one day, which we thought previously impossible, as you have to have one full tide cycle to check the Rotten Corner of the Motykley Bay. This time we decided to give it a try at the low tide period, which fall at the first part of the day, but had very high low levels (-1 in contrast to -4m). This proved to be a successful idea in general, but had caused us some health problems at the end.

Our weather window. Taken from here: For COSM-1 Asia Pacific, HRIT, ENH, ROUTINE.

On 2 August we set off from the Balagannoe to the Motykley bay exactly repeating the dates and route of the 2011 and 2012 trips. In really early early morning got out of the Balagannoe at the 2/3 high tide, which was coming in, and managed to check all nests along the coast, thank to relatively calm weather. We get to the Rotten Corner at the beginning of the low tide time, and managed survey the coastline reasonably close to shoreline. At the mouth of the small river in the Northern corner of the Rotten corner we were greeted by a group of the Balagannoe fishermen with the gun. There we no direct confrontation, but we thought that this is an indication how desperate local people were to get their caviar. Mudflats which started to appear between of us prevented both parties to talk to each other.
We carried out the survey up to the Shestakova cape, however we did not manage to see the pinnacle with the last nest, as it was covered by severe fog. The fog was coupled with severe adiabatic wind, so we decided to rush towards the Talan Island. Spafariev island was also covered by the thick fog.
By the time we get to the Talan island most of the island was covered with thick fog. We delivered bread to the island inhabitants, had a short talk (30 min max), and keeping in mind closing window of relatively good weather and approaching rain storm we went off to the Onatsevicha cape and to the Balagannoe.

We managed to get to the Balagannoe with the coming evening tide some 20 min before we were hit by severe rain. Packing of the boat and gear we managed under rain and got severely wet. Nevertheless we managed to get to Magadan with the same tide cycle and got to the city by midnight. Next morning we both had to book a chiropractor session. A week long rain was reported at the Balagannoe and Talan after our departure.

 We did get information about the Talan and Spafarieve Island eagles from the Talan inhabitants and from botanists who were staying on the Spafariev island in July.

The Talan island had one nest with 2 chicks, and Spafarieva Island had 2 nest with at least 1 chick each.
In total this stretch of the coast had 13 productive nests with 17 chicks. Only 4 nests had duplets. It total there were 24 occupied territories along the mainland, and seven on both the Talan and Spafarieva islands.

Odyan Bay trip.
We set off from the Ola on 6 August on a new speedboat which was acquired by the Magadan State Nature Reserve two months earlier. We had our boat and fuel inside this nice seaworthy schooner. However it has to be said, that the weather window for this trip was also tight, but stretched for 2 days. So we decided not to waste the good days and set off in poring rain. Onboard we had 2 hidrobiologists of the team invited by the Nature Reserve for the tidal zone surveys of the Koni portion of the reserve. The other members of this crew stayed at the Ploskiy Cape Ranger’s station. So Irina, myself, 2 hidorbiologists, and two rangers with our boat and fiewl went off. The speed was about 50 km/hr, moderate swell, with the visibility of c. 30 m and pouring rain. I was holding my gps in front of the range’s eyes all the time, as otherwise we won’t find our way trhouth the estuary mudflats and across the seas. In one hour and 20 minutes we were at the Ploskiy Ranger’s station, completely wet. We were greeted by the hidrobiologists, who on the previous day lost their dingy inflatable to bear. The bears were constantly visiting the station day and night, as the ranger, in his wisdom decided to donate his dogs to a friend. They already lost the outside kitchen with some losses of the food.

            The trip towards the Taran Cape on 7 August returned 4 occupied territories; none of the observed pairs had chicks. One pair was observed busy renovating the nest. We saw 2 or three minke whales at the Taran cape.

            On 8 August we set off to the Odyan Bay and subsequently to the Ola. The good news was that the Umara island had the nest located in the same spot, as in end of 1990s, on the slab at the top of the island. It had 2 chicks. In total there were 7 productive nests along the coastline, with 5 nests having 1 chick and 2 nests had two chicks. Up from 3 occupied nests in 2012.

Staritskogo Peninsula trip.

We made circumnavigation of the Staritskogo peninsula on 9 August, repeating the date of the 2012 trip, but making the trip in opposite direction, starting from the Gertnera bay, and ending at the Nagaevo bay (Figure 10). On this part of the coast we have 4 occupied territories and 3 nests with chicks (2, 1, and 2 chicks). The nest at the resort was no longer occupied.

Pictures of the tip can be seen here.

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