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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: January 17th, 2010, 8:14 pm 
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An intelligent parrot.!! (I already knew how clever parrots are..from experience.)

http://videos.howstuffworks.com/discove ... -video.htm

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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 20th, 2010, 4:07 pm 
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Grin and bear it, or take flight?
About those blackbirds - in eagle winter camera and elsewhere - partial migrants in north Europe, who tend more and more not to migrate:
When is it worse to try to migrate than to stay, and do they have a choice and make some kind of decision?
Did some leave when the winter really showed what it would be like?

Happened to read a book last night which seemed to have some answers:
Migrating or not is probably genetically programmed in an individual. So some migrate always, some don't ever.
There seems to be a trigger factor for migration time, something (or things) that lets out signal substances for action in the bird. It is not only weather conditions - as temperature and daylight - but may vary among species. This migration readiness or urge disappears again after a certain time.
So, the long and short of it looks to be that after the migration urge period for blackbirds is over, the travelling instinct won't be triggered, and the ones who stayed won't try to migrate, not even when conditions for migrating could be fine, and for staying, wretched.
Rowanberries are all gone in my part of Stockholm, some barberries still left. Not a bit of black ground to be seen, all snow. Today with howling wind, stinging snow and -12 C must be really bad.
Any opinions from bird experts and watchers, please?


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 20th, 2010, 5:36 pm 
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Bird migration (and navigation) is a fascinating subject.

There are white storks that do not migrate (several nests in Germany, for example) and I have been given to understand that this is becoming increasingly more common (some warmer winters lead to survival and reproduction of individuals that do not migrate?). If individuals of any species stays behind and perishes, then that genetic strain is lost.

I have also been fascinated by the attempt to save the Whooping Crane here in North America --- humans have to teach the captive-raised juveniles to migrate because the birds must have the genetic tendency "unlocked" and be shown the route the first time. There are non-migratory populations of these cranes, because no one (natural parent or human) ever taught them to migrate.

I also worry about those birds that migrate over Malta and other areas and are tracked and shot by evil-hearted humans.

What is the book that you read?


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 21st, 2010, 12:42 am 
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bociany wrote:
------
What is the book that you read?

A rather basic bird book in Swedish, Magnus Ullman: Fåglarnas liv (Bird life), 1994, that manages to cover a surprising amount of facts in less than 250 pages.
But it wasn't where I read what I thought I had read :mrgreen: - late nights etc.
Second source guess was an Estonian classic, Eerik Kumari, Lindude ränne (Migration of birds) but no again.
Both books take up long lists of things that influence migration time, particularly of course Eerik Kumari, and both note that the importance varies between species. Eerik Kumari points to body fat reserves as one factor in deciding readiness for autumn migration.
Those winter staying blackbirds have probably used up the best part of the extra fat they had in autumn, and would certainly have a hard time to put on any more now. And if they could, there would be no serious reason to migrate anyway :mrgreen:


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 21st, 2010, 12:46 am 
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For as long as I can remember our blackbirds have stayed, year round. I have been here since 1984! Same old blackbirds, stealing my seedlings in spring, and eating apple and raisins and fat bits in winter!


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 21st, 2010, 1:10 am 
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Jo UK wrote:
For as long as I can remember our blackbirds have stayed, year round. I have been here since 1984! Same old blackbirds, stealing my seedlings in spring, and eating apple and raisins and fat bits in winter!

It is the heroic arctic blackbirds here up north, who fatten up in autumn to get across to you. At a guess you - and the blackbirds, including the holidayers from Scandinavia and Estonia - don't at the moment have a howling wind, -12 C, stinging snow, and 1+ m snowdrifts (in town & not counting the mini Himalayas built up by street snowclearing gangs)
Seriously, how the birds can have managed these last two days is a puzzle.


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 21st, 2010, 2:16 am 
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bociany I had not really thought about there being two populations of birds those who migrate and those who don't.


(Liis, evil alice says it was 16C here today) The little birds are happily flitting around my yard.


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 21st, 2010, 11:41 am 
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alice44 wrote:
(Liis, evil alice says it was 16C here today) The little birds are happily flitting around my yard.

Alice, we in Stockholm had 16C too, this morning. :whistling: -16C, that is.
But perfectly white, clean, wind-sculpted snow covering everything - until snowploughs, sanders and happy kids have a go at it.
Birds can migrate in surprising patterns. In "leap frog" migration, from a population spread over - say - south to north Europe during nesting, the northernmost nesters go furthest south for winter, for instance to Africa, and those in the middle or south move little if at all.
Even my computer gets a headache from all the things involved in the why, when, where of bird migration!


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 27th, 2010, 10:50 pm 
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I am watching
http://www.hawaiinewsnow.com/Global/cat ... menu55_1_1
Hawaii is expecting tsunami waves in about 25 minutes from now. The TV station says it has received reports that "eagles are behaving weird in California"
Knowing that it is worth watching the changes in behaviour of animals, birds prior to natural disasters, I wonder if anyone here can find out anything more?

The TV station seems to be broadcasting two streams of talk so it is difficult to make out what they are saying, but there is a webcam watching the sea.


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 27th, 2010, 10:58 pm 
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I am watching too now
very impressive


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 27th, 2010, 11:20 pm 
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Jo UK wrote:
I am watching
http://www.hawaiinewsnow.com/Global/cat ... menu55_1_1
Hawaii is expecting tsunami waves in about 25 minutes from now. The TV station says it has received reports that "eagles are behaving weird in California"
Knowing that it is worth watching the changes in behaviour of animals, birds prior to natural disasters, I wonder if anyone here can find out anything more?

The TV station seems to be broadcasting two streams of talk so it is difficult to make out what they are saying, but there is a webcam watching the sea.


Changes in behavior would not be surprising, but were any details provided? What do they mean by "weird behavior" and where in California?


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 28th, 2010, 12:45 am 
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Sorry, I can only say that a TV presenter said "We have had an e-mail from someone in California to say that eagles are behaving weird."

The same presenter tried to get a meterologist to comment about the behaviour of wildlife, but no luck - he couldn;t see any wildlife from his viewpoint. They did say that whales had moved away from the area.


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 28th, 2010, 12:56 am 
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Has there been tsunami damage in California? A member on another forum mentioned it. I will try to find more.


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 28th, 2010, 12:56 am 
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thanks, Jo - I heard them mention "weird behavior" by the whales - but moving away does not seem weird at all in that situation. The humans, on the other hand, do act weird - going down to water's edge to watch. Fortunately, it seems a non-event at the moment.

ETA: I heard something about Ventura, California -but nothing big, I think


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: February 28th, 2010, 1:16 am 
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I just read there was a 7 foot wave -- but I do not know how reliable that is.


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: March 15th, 2010, 9:37 pm 
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i could not decide where to post these pictures, but this is definitely odd behavior...
today, in our garden in city center, a sparrow hawk or a goshawk caught a pigeon :shock:
the hawk was standing on the pigeon, pushing it`s head under snow...after a while sth disturbed the hawk and it took off...leaving the pigeon (still alive) on the snow!
we couldn`t leave the poor bird there just like that, so we lifted the pigeon a little ....and it flew away!
i know that the hawk was left without the dinner, but it was jut infront our window... :puzzled: and the pigeon is our everyday guest :D
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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: March 15th, 2010, 9:47 pm 
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:???: I hope the pigeon was not terribly injured when the hawk caught it ... sometimes birds will escape being dinner but then succumb to injuries. Let us know if the pigeon returns to visit.


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: March 15th, 2010, 10:28 pm 
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there was no blood and only a few small feathers on the snow, obviously the hawk was just holding the pigeon still, it had not pecked it yet!
hopefully it had no big injuries :puzzled:

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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: March 15th, 2010, 10:35 pm 
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"no blood" is good! :book:


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 Post subject: Re: Bird Behavior: A Discussion
PostPosted: July 11th, 2010, 6:47 am 
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I became interested in what Linda and Sulev on the WTE nest camera brought for their chicks: what kinds of fish, and how much else. In winter WTEs seemed quite happy to eat meat. Of course the results here may reflect our posts, screencaps and interests as much or more than the eagle family's real diet.
This was 2009. How much different is it this year?

Summary
In 2009 (March – mid-July) there were birds on 13 occasions, ”some animal” 2 times, otherwise fish, whole or in pieces, according to posts and screencaps. The fish were not often identified, but pike was most often mentioned, also perch.

Backgound & details
I have checked last year’s discussion, but by far not as carefully as Ame did for her research. I haven’t checked any Pontu images (if they are available at all any longer), and not looked at this year’s records.

Camera went on-line in the beginning of March (March 4, 2009). Eggs were laid on March 12 and 14. Sulev brought food for Linda while she was incubating the eggs, but she also went fishing for herself. Chicks were hatched on April 19. Camera was running until October 7, but after mid-July nest was often empty and eaglets even spent the night elsewhere, and feeding was only occasionally mentioned in posts.

During the feeding period with eaglets in the nest, April 19 to around July 15, there were 12 reports of birds brought in for food, mostly in the later half of the period: 8 reports June 15 – July 15. Probably half of them or more were cygnets. Urmas explains in a post on June 20, 2009 that they probably were mute swan chicks.
Sulev also brought a bird (a crow?) for Linda on April 11.

Meat – not fish or bird – was mentioned twice: April 2 (rabbit?) and something unidentified with 4 legs on May 2.

The fish that were brought to the nest are mostly not identified in posts, just ”fish”. Pike, bream, perch were named. Pike was also identified in a video (April 15). Ruff, or some kind of "dotted" fish was discussed (May 4). According to information from Looduskalende (posted by Yarko, May 5, 2009) , pike and pikeperch would be the expected prey in the sea in this area.

On my laptop screen few of the fish in the screencaps seem easy to recognise. It might be better with a larger screen, and of course with first-hand knowledge of the fish species that are common there.

In literature it is said that WTEs generally divide the prey into pieces before bringing it to the nest. In the forum posts whole fish (”huge fish”, ”a large fish”, ”a fish”) is quite often mentioned.

Both fish and birds were seen to be brought in alive occasionally (3-5 times). Actually the last bird, a black and white one, may have escaped. The screencap (July 13, 2009) shows it sitting on a branch beside the nest.

The interest in the forum was more on the feeding of the eaglets, and not so much on what was brought; the preys may be better identifiable with slightly different screencaps. I have not compared this year’s screencaps to see if the current camera position is better for prey identification.
Mutikluti who has been watching the cameras most carefully of us all and who is not so very far from the eagle region, probably knows much more already.

How many times food was brought in was discussed twice at least. On April 21, 2009 it is mentioned that the chicks are fed nearly every hour, later (May 8) it was noted that there were at least 6-7 feedings a day, but that some feedings went on for a long time. I have just looked for ”major” feeding events with possibly identifiable prey in posts, not tried to count or analyse all posts that mention feeding. There is a very large uncertainty and distorting factor anyway: how many feeding occasions were not noticed or mentioned at all?

Next year?
On the whole it looks as if the eagles’ fish diet was rather more varied than only pike and pikeperch. So it should be interesting to try to identify the species more often, to see for instance if there are changes with the season, or with the growing up of the chicks, or in years. Asteria? (June 10, 2009) suggested that Sulev brought smaller fish to encourage chicks to eat by themselves, and large ones to feed them.


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