Saturday, August 25, 2012

Wing-tagged adult found!

We found an eagle with a wing tag E4 during June surveyes. The eagle is a male at the nest M40-95 on the Chelomdja River. 
This nest was occupied in 2009 and produced first chick only in 2011. Mr. Ueta an H. Nakagawa wing-tagged this eagle on 16 February 1995 as 5 years old adult. They trapped it at Furen lake, Hokkaido, N43°21'15", E145°16'50". This means that the eagle was first breeding at age of 19 years old, and it is now 22 years old! This is unbelievable!
Photo by A. Gnezdilov.

Photo by Ueta.

Friday, August 24, 2012

The Steller’s Sea Eagle surveys of 2012: 3 (with Drone (UAV) deployment)

The Steller’s Sea Eagle surveys of 2012
The results of the 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 and Motykley Bay. We were accompanied by Michael Rodgers, a senior student of the Bryn Athyn College. His trip was made possible to the Bryn Ahyn travel loans.
            The order of trips was un-conventional. Due to severe cyclons which made weather on the coast unbearable we started from the Kava-Chelomdja portion of the Reserve (July 25 – 1 August), then proceeded to the Motykley Bay and Talan island (1 – 4 August), then to the Odyan Bay (5-6August), and and finally to Staritskogo peninsula (8 August). The weather window gaps at the sea were the main constrains for this season.
The Kava Chelomdja portion of the Reserve showed a good breeding success this year, as was already reported by the June trips. We covered our usual study area (upstream to the upper chum spawning grounds at the Chelomdja (overnight at the Kheta ranger’s station), and up to the Ikremun ranger’s station on the Kava (see map below). Both rivers had NO pink salmon run. I saw only 2 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 was no seal rookery at the Kava-Chelomdja confluence this year. A fisherman who usually accommodated us at the Balagannoe was complaining that this year they managed to harvest only 2 kilos of caviar, whereas in a ‘usual year’ he gets 2-4 tons. The coho salmon was not abundant either, so the fishermen were counting on the Silver Salmon run which was expected to be good. There was no commercial salmon tickets issued this year, so the fishing camps on the river were idle.
However, the eagles were doing good. On the Kava trip we deployed a drone (quadrotor helicopter I assembled from the kit The drone has a video camera (GoPro) and in parallel transmits live video to the video goggles. We deployed the drone only when the contents of the nest was not clear. On the Kava I flown 4 missions.
In total we had 8 occupied pairs on the Kava, 3 pairs had chicks: 2+2+1 (see table Occupancy in the drop box).
The deployment of the drone was quite a success. The mission takes max 10 min, and delivers clear visual imagery of the nest contents. The tricky part was transportation of the drone. I made a case filled with foam, which also acted as a launch pad. Our student M. Rodgers was acting as a “spotter” advising me on the air situation, Irina was watching through the video goggles and advising me ‘left’, “right” and “higher/lower”, so the nest would be in the view. I was obviously controlling the craft.

Transporting drone to a launch site. 

Drone hovering at a nest

Flying team: spotter (M.Rodgers who took this picture. He sees the big picture), I. Utekhina looking through the video goggles, and commands the pilot (E.P.). Launch pad (the case) is in deep grass in front of the pilot.

We had no reaction of the eagles to the drone. However I crashed the drone during one mission (repaired the craft on the spot). In the nest M30-90 the second chick was spotted only thanks to the drone. From the river we saw only 1 chick. At one occasion we had a hobby investigating the drone. So, despite some logistical difficulties the drone was extremely useful to save time in some cases.

Hobby investigating the drone above an eagle nest. 

Drone hovering at a nest. Note the drone at the upper right corner. 

The same nest as viewed by/from the drone.

The Chelomdja river was checked on 30-31 July. We went upstream to the spawning grounds eager to see what happened to the early nest there (the one Irina was reporting in June). We found the nest empty ut saw a large flying chick. The spawning grounds were totally empty. I do not recall that I saw it empty ever. I flew a drone mission above the stretch where the spawning grounds were and so no fish dead or alive. At the same day we flown a drone mission at the nest M105. This nest had 3 hatchlings in early June. However this time our drone mission returned only 2 grown chicks. So the first nest with 3 chicks on a river has not happened.
            One nest which had a dead chick under it and a female incubating was found empty (again, drone mission flown). One nest was clearly destroyed by a bear.
It total we had 4 nests with chicks on the Chelomdja (1+2+1+1) totaling 5 chicks at the 14 occupied territories.
 We spend night on the Khuren ranger’s station (as per usual).
            On the Taiy we had 3 pairs with chicks (one each).

This means that this year was very productive for the Tauy-Kava-Chelomdja river system.

Motykley trip.

On 2 August we set off from the Balagannoe to the Motykley bay. We spend night at the spit at the north-eastern part of the bay. While surveying the coast we were accompanied with a pod of orcas (Figure 8). The orcas were scraping the shallows and were coming very close to the shore. We saw eagles drawing no attention to orcas. We surveyed the Motykley bay (the rotten corner) on the following day and went along the coast to the Shestakova cape, i.e. getting the same route as in 2011. At the Shestakova cape we hit a sever storm and fog and had to move with the wind to the Talan island.
Orca scraping the shore in front of the eagle nest (B10, the nest is not visible). Top: Orca heading towards the boat at the nest B9. Talan island in the view.
The Talan island was covered with thick fog. Our two attempts to check the nests were not successful. However we know that the two occupied nests contained 2 and 2 chicks.
In total this stretch of the coast had 26 occupied nests with 19 chicks. Only 3 nests had duplets.

Odyan Bay trip.
We set off from the Ola on 6 August. We had about 14 hr of the weather window before the cyclone, so we decided to cover the Odyan bay in one go without spending the night. The route was identical to the route of 2011. The sea was relatively calm, and was sunny most of the day.

To our surprise only 3 nests were occupied and with chicks on this coast (1,2 and 2). Total occupied pairs was 11.

I guess the reason of lower breeding output was long period of ice cover which lasted till June (at least what locals told me). I think I will be able to say more about it when I compare ice data.

Staritskogo trip.

We made circumnavigation of the Staritskogo peninsula on 9 August. The route was identical to that of 2011 (Figure 10). On this part of the coast we have 5 occupied nests with chicks (1, 1. 2, 1,1), however the location of the nests changed. Nest A6 was located further away from the Nagaevo bay, S5 is now most productive, nest S2 is no longer occupied, and S4 is now shifted from the birch tree to a sea stack S3. The nest at the resort has only 1 chick compared to 2 last year.