Migration Map

Migration Maps, Tõnn, Greater Spotted Eagle and Black Storks
Post Reply
User avatar
lispet
Registered user
Posts: 1687
Joined: July 1st, 2012, 9:31 pm
Location: Tampere, Finland

Re: Migration Map

Post by lispet »

Great work Kukelke! :thumbs: Thank you!
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

October 16

A new batch of data came in again (updated til the morning of the 15th), so lets have a look at osprey Tiiu's movements the last days.

In my post yesterday, I told that Tiiu probably went fishing in the early hours of October 13, before the data was transmitted. Her movements after that, still on October 13, indicate that she indeed caught breakfish and ate it perched in a tree some 500 m south of her roost. It must have been a good catch because she didn't do much the whole day. After eating her fish she flew to another tree some 30 m NW of her breakfast tree, and decided later on to fly a tad bit north again where she probably roosted for the night, some 400 m to the north-northwest.

October 13 in short - yellow line Tiiu's movements on the 13th; purple arrow is her roosting spot (Oct 12-13); blue arrow the place where she caught fish; black arrow her breakfish tree; green arrow the other tree nearby - bird icon is where Tiiu roosted for the night of the 13th-14th:

Image


On October 14 Tiiu decided to go inspect the Komoé River again. She flew as usual first northwest to the area some 7 km east of the river, probably perched in a tree there, before turning almost straight west towards the river. It's likely that she caught a fish there in a shallow part of the river, which on the map looks like bare rock (remember the map is made in the dry season when water levels are lower). After this, Tiiu then flew straight back, with a fish most likely, to the area in the southeast again. The remarkable thing here is that she flew in a straight line to her southeast area, and not, as she has done every time before, first some 7 km right to the east, eat there, and only then back to the southeast.

October 14 in short: yellow line Tiiu's movements on the 14th; purple arrow is her roosting spot (Oct 13-14); green arrow possible perch (she changed direction right where there's a solitary tree); blue arrow where she probably caught fish; black arrow where she roosted Oct 14-15:

Image


Close-up of Tiiu's fishing expedition to the Komoé River; coming from the east, probably diving with succes (black arrow) and then heading to the southeast again:

Image


And a close-up of the tree where Tiiu ate her fish and roosted Oct 14-15; again a solitary tree next to what looks like a small pond (which probably is bigger now), just how ospreys like it; a lonesome tree in or near water, so they have both food on the doorstep and at the same time easily can detect possible dangers:

Image
aita
Registered user
Posts: 3205
Joined: April 29th, 2009, 9:39 am
Location: Estonia

Post by aita »

User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

October 18

More data came in, so time to try to analyse osprey Tiiu's movements again.

On the 14th (see my previous post) Tiiu had been at the Komoé River and flew back some 30 km to the southeast again, where she perched and probably ate her fish. Later that day she flew another 2 km south to roost there.

Tiiu's roosting spot from Oct 14-15:
Image


On October 15 Tiiu probably caught a fish and flew with it some 500 m to the north to eat it in a tree there. Later that day she flew back to nearly the same spot where she possibly caught another fish before she flew some 300 m to E-NE to roost there for the night.

Tiiu's route on the 15th - arrow where she started, yellow line her movements and bird icon where she spent the night of Oct 15-16:

Image


Then, on October 16, Tiiu flew all the way to this favourite area some 7 km east of the Komoé River again, to a solitary tree she has been before a couple of times. I'm not sure if she only perched there or actually caught something to eat before she flew back to the southeast again (her turning point there could be the aforementioned tree, but also the water below it, if there is water there):

Image

Close-up of her turning point 7 km east of the river:
Image

The question is why would Tiiu fly almost 60 km to that area and use extra energy if there wasn't some sort of benefit. I have no idea how many calories she would use on that trip, probably not too many because ospreys can use more than a week to cross the Sahara, and fly 2500 km without refuel, so 60 km is just a stroll around the block, so to say. So if the reason isn't food, then perhaps the benefit for Tiiu is that this area in the NW is undisturbed and has no human activity, or has less dangers in the form of predators than the area in the SE.
User avatar
Janne+Ais
Registered user
Posts: 1325
Joined: March 29th, 2013, 6:43 pm
Location: Germany

Post by Janne+Ais »

Kukelke wrote:On the 14th (see my previous post) Tiiu had been at the Komoé River and flew back some 30 km to the southeast again, where she perched and probably ate her fish.
I find this remarkable! With her fish??? :shock:
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

Kukelke wrote:On the 14th (see my previous post) Tiiu had been at the Komoé River and flew back some 30 km to the southeast again, where she perched and probably ate her fish.
Janne+Ais wrote:I find this remarkable! With her fish??? :shock:
Some ospreys nest up to 15 km from the nearest water while other ospreys nest in areas where sometimes there's still ice on their main feeding grounds when they arrive in spring, so they have to fly far greater distances to have access to open water. Also, migrating ospreys have been observed flying with a fish in their talons as they went. So it wouldn't be that unusual to fly 30 km with a fish, I think.
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

October 20


More data came in and things get a bit complicated now. Osprey Tiiu has been flying about a lot on the 17th, and the red lines indicating her route now seriously begin to overlap, so it gets extremely hard to figure out which route she took exactly when, and I've not yet discovered a possibility to filter out only her route on a particular date. So I'm afraid I have to skip the analysis of what Tiiu did on the 17th. All I can say with certainty is that she visited the area of the agricultural field again on that date. She might have fished in the small pond there, or she might just have been perching there. She took exactly the same route back as she came, so the red lines overlap here too (only a few km further to the southeast one can see the red lines diverge a tad bit, but still only some 10 m apart).
Here a screenshot of her visit there:

Image


However, early on October 18, Tiiu left one of her favourite roosting trees in the southeast, and flew directly the 35 km to 'her' bend of the Komoé River in the northwest of her wintering grounds (without first visiting the area 7 km east of that, as she used to do before), and she was definately fishing there when the data were sent:

Image


After that Tiiu flew those 7 km to the east and perched in a tree there, in an area she has frequented earlier on. Most likely she caught a fish in the river and ate it here before she possibly moved southeast again:

Image


It could also be that she stayed in the tree mentioned above for the rest of the 18th, because the red line from the tree 7 km east of the Komoé River to the SE is completely straight and doesn't indicate any stops. Anyway, early on October 19 Tiiu was in the southeastern part of her wintering area again, west of the town of Agnibilékrou.
Riitta
Registered user
Posts: 5708
Joined: May 20th, 2013, 6:20 pm
Location: Germany NRW

Post by Riitta »

:hi: Kukelke :2thumbsup:
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

Thanks Riita :wave:
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

October 21

New data came in this morning, so lets continue with the attempt to analysise osprey Tiiu's movements.

As said in my previous post, Tiiu was in the far southeast end of her wintering grounds early on October 19 when the data were sent. I'm not sure what she did there, perch or maybe fish, as the red line is close to a tree, so it could be both. Most likely she perched and roosted in the tree there. Anyway, after her visit there, Tiiu decided to fly to the northwest again, to the area some 7 km east of the Komoé River.

Tiiu's visit in the southeast:
Image

Tiiu's arrival in the northwest, some 7 km east of the river (the yellow line crossing the green circle is where Tiiu was the day before):
Image

After that it looks like she could have been fishing here, ate her catch in a tree nearby, caught another fish and flew to the southeast again, carrying her possible second catch with her:
Image

And this is where Tiiu was early on October 20, when the data were sent, in or near the small group of trees which she has visited many times before:
Image
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

October 23

On October 20, Osprey Tiiu left the southeastern part of her wintering grounds again, and flew to the Komoé River, via this area 7 km east of the river first. Her movements at the river indicate that she tried to fish there, after which she flew all the way back to the southeast again:

Image


On October 21, Tiiu might have been fishing in one of the small ponds in the southeast:
Image


After that she did a lot of flying in the area there (arrow indicates her position on the previous screenshot, yellow line her movements after that):
Image


Early on October 22, Tiiu was then back in this area 7 km east of the Komoé River, visiting three of her favourite trees there (the yellow line coming from the southeast is the continuation of the yellow line going northwest on the previous screenshot):
Image
Owlie

Post by Owlie »

Do we know the interval of tracking signals - are they regular? The lines are so geometrical, which can not mean that Tiiu's flight routes are so straight, I suppose.
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

Owlie wrote:Do we know the interval of tracking signals - are they regular? The lines are so geometrical, which can not mean that Tiiu's flight routes are so straight, I suppose.
Most modern trackers can send signals every minute, sometimes even less. They can be programmed to send at longer intervals too. Most of them also have sensors for movement, so the trackers can be programmed not to send signals when the bird sits still on a perch and does nothing, for example, in order to safe battery power.

I've no idea about which brand and model of tracker Tiiu is fitted with exactly, but the fact that the tracker picks up her fishing attempts (sharp changes of direction over water) indicates that it at least sends signals with short intervals when she's moving about.

Maybe Urmas can give us the technical details of Tiiu's tracker?
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

October 25

On October 22, after the data was sent (see previous post), osprey Tiiu went fishing in the Komoé River, 7 km west of her initial position. She flew first to the bend of the river where she has been before, and then to a new bend, before returning to the area 7 km east of the river.

Arrow indicates her start position, yellow line her route, the bird icon where she was on the 23rd when the data were sent:
Image


Next day, October 23, started the same: Tiiu flew west to the river, fished at her favourite bend there, and then she flew in a straight line all the way back to her area in the southeast, where she changed trees a couple of times.

Arrow starting point at the 23rd, yellow line her route, and bird icon where Tiiu was early the 24th:
Image
User avatar
macdoum
Registered user
Posts: 6786
Joined: November 17th, 2008, 12:12 am
Location: Alsace, France

Post by macdoum »

Kukelke great work on tracking this osprey. :2thumbsup:
Carmel a member of SHOW .. I hope you love birds too. Its economical. It saves going to heaven.
Emily Dickinson
Owlie

Post by Owlie »

It is so fascinating to read Kukelke's analyzing of Tiiu's movements - Kukelke has studied so much of ospreys' lives and can give us clues what Tiiu is probably doing, in what purposes she is moving back and forth over there in Africa. I admire Kukelke's imagination and knowledge and enjoy his comments on any topic. He makes topics interesting - it is important for us "mortals" to have someone delivering also experience and knowledge - as we seldom hear from the Kotkamen themselves ... The Kotkamen hopefully appreciate Kukelke's support!
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

Thank you all for your appreciation, but keep in mind that my attempts to analyse Tiiu's movements by zooming in and out on the map are nothing more than assumptions and perhaps qualified guesses.

Also, Tiiu's doings, and other osprey related things, are often discussed with Paul Wildlifewriter, among others, who has a great insight in all of these osprey matters. Both Emyr Evans of the Dyfi Osprey project and Tiger Mozone possess a wealth of osprey knowledge too, much more than I do really, and I'm happy that all of these people are willing to share their knowledge with me, which I in turn try to pass on as good as I can.
Owlie

Post by Owlie »

Kukelke wrote: ... my attempts to analyse Tiiu's movements by zooming in and out on the map are nothing more than assumptions and perhaps qualified guesses. ...
You express it in words - that is what we others can feel to be helped with :2thumbsup:
User avatar
Kukelke
Registered user
Posts: 3595
Joined: July 16th, 2012, 3:09 pm
Location: The Netherlands

Post by Kukelke »

October 27


After last update it looks like osprey Tiiu stayed in the southeastern part of her wintering grounds. There was some flying to and fro on the 24th, and I couldn't detect possible fishing attempts.
Purple arrow starting position on the 24th, blue arrow where she was early on the 25th, yellow line her movements:
Image

Early on the 26th the map indicates exactly the same position as early on the 25th, so I assume the data for the 26th is not yet plotted on the map.
Urmas
Registered user
Posts: 1301
Joined: October 27th, 2008, 7:44 am
Location: Estonia

Post by Urmas »

Well, Sunday the Ecotone (producer of logger on Tiiu) server was not responding about data - therefore there was no updates.
In general I try to update map data every morning as during the night usually the data updates in server happen.
So nearly every day some new data can be seen, but if I'm not near computer or internet, then delays occur. Also not every day the birds are in GSM network to send data stored in device. Though Tiiu sends quite regularly the data, so the network should be there quite OK.

Think Kukelke is right explaining the situation in Tiius surprising stopover (or wintering site). Of course, would be great to have some contact in place, but it could be difficult to find out. Ivory Coast is French speaking, plus probably there is no such wide internet coverage available. Anyway, could be that some forum user knows somebody there nearby and can ask the overall situation.
There are also no photos posted in Google Earth about that area...
Post Reply

Return to “Migration Maps and News”