torsdag 21 februari 2013

Visit to Bavaria


Christian, Berenika, Auguste, Hugo, Mathias and Ivo
Last week we went to Bavaria in Germany to visit Auguste von Bayern and her research group. She works mostly with jackdaws (Corvus monedula) and New Caledonian crows (Corvus moneduloides) which are housed in number of outdoor aviaries in Leutstetten. The New Caledonian crow is endemic to The New Caledonian islands and is famous for its tool-use and abilitiy to solve sophisticated cognitive tests. We only met the crows briefly, but I was totally mesmarized by their soft and endearing calls.



The last common ancester of ravens and New Caledonian crows lived 12 million years ago, which is about twice as long as the last common ancester of humans and chimpanzees (6 mya). An interesting perspective, as I would think that most people (myself included) quite often think of different species of crow birds as "just crow birds".

//Helena

fredag 8 februari 2013

Top bird

Rickard submissively backing away from Siden
This week we have some constuction work going on next to the aviaries, so the ravens have some time off from training. But as soon as I came out they all fly down to see what funny or edible stuff I might bring today. And all birds want to be first. At times like this, it's good to be the top bird; you just walk around, looking hard and strong, and the other birds immediately retreat  - all fluff and bows.
If you are the undisputed dominant bird, it seems as if little aggression is needed to keep the others off. Just look how effectively Siden (silver ring) shoos away all other birds but his sister Juno (orange ring) - just by walking around in a certain manner.


//Helena

måndag 28 januari 2013

Above zero!

When I came out to the ravens to do some training sessions just before lunch, all birds were perching on the highest branch. Nobody seemed at all interested to come down to me, which is very unusal, unless they are afraid of something. Not even Siden and Juno paid me any attention what so ever. Hrmm. A quick glance around the aviary immediately solved the mystery. The bathtub which I had un-iced and filled with water just an hour ago was totally emtpy! And a second glance at the ravens confirmed my suspicions - they had all taken a bath! And of course, this is the first day above zero  (2,3 Celcius) in two weeks so who could blame them!
A picture from the summer
During the summer, the ravens bathe at least once a day, but in the winter they seem content with taking snow baths. We have also noticed that they eat at lot of snow, and sometimes they even seem to prefer that instead of fresh water. But when the temperature rises above zero after a long period of coldness - the situation apparently calls for a bath in the tub!
//Helena

torsdag 24 januari 2013

Great day

Today was a great day, in several aspects. First of all, the weather was superb - one of these sunny winter days with blue sky and almost no wind. The other good thing was that the ravens seemed to agree with me. In our experience, raven-mood also change with weather, and on sunny, calm days they are easygoing and joyful.
Yesterday, I had left a selection board close to the net, hoping that the ravens should get enough used to it to not make a fuss of it today. And this time, the plan worked. As soon as I came out, Siden and Juno expectantly flew down, waiting for me to put some items on the board. Hopefully one of the items would be a frolic. All the other birds were equally cooperative and today I actually managed to sparate all birds but Gulan (who is the only bird who won't come down to us), and get them to select items from the board. With one exception, that is. Hans was still not in the mood for work and immediately started with his content, purring display sounds.
The runway that connects the two aviaries.

onsdag 23 januari 2013

King of the aviary

Today my plan was to train the ravens to be separated. When they were younger this was almost impossible as they they got very scared when left alone in either of the aviaries, and we stopped trying. Now, the situation is sometimes quite the opposite - they seem like it too much! Especially the low ranked birds seem to enjoy the moment of solitude - beeing king or queen of the aviary for a moment - with no dominant bird setting the rules. When this happens, they totally ignore me, fly off to perch somewhere and start to display.
Hans in a typical raven display posture
 And the display is magnificent, both the impressive body posture with the chin feathers all fluffed, and the charachteristic sounds, leaving nobody in doubt of who's in charge - at the moment.
So this is what happened today. Hans, ranked as number three out of four males, came down to retrieve one frolic, stuffed it securely away in his pouch, and then flew off to enjoy his moment.

//Helena






torsdag 10 januari 2013

Habituation training

Much of the time with the young ravens is spent on general habituation training.  For example, they must be comfortable with being separated in smaller groups, later on also alone. As the ravens are highly social and enjoy interacting with us, the lower ranked birds are not allowed to interact with us if higher ranked birds are present. They must also be trained to come down into the experiment rooms, and as they don't particularly like confined spaces this can take some time.
Lillen is sitting in the sun outside the semi-dark experiment room. His eyes are set on the tasty frolic waiting for him. If he dares.
The ravens must also be habituated to new items, which later will be used in the experimenting. Crow birds are so called neophobic, which means that they are afraid of almost all new and unfamiliar things, and therefore must be habituated to them. Crow birds seem especially afraid of long items, so next week we'll re-introduce a camera tripod (as documentation is demanded when experimenting) to see if they remember it since last time.


The two siblings Siden and Juno
We also try to make the ravens feel comfortable coming down to the research cabin (which is primarily built for humans). If some bird for any reason should need to be examined or treated, we want to make the examination as smooth as possible. Using the cabin, we only need to open the window and take one bird inside. Then the bird can still see its fellow birds and hopefully the experience will not be particularly stressful to it.
The ravens like to sit on the open windows peek inside. The problem is that they also like to destroy things, which is evident on the wooden window where parts are already missing.









Always on the look out for a treat, Siden abandons the window to come down to me.
//Helena

tisdag 11 december 2012

Raising baby ravens

The ravens are now 1,5 years old...this is what it looked like in their early days. A lot of hungry mouths to feed. According to Bernd Heinrich, a famous corvidologist, a baby raven can eat up to 800 gram meat per day at a certain point of its developmental stage. Quite impressive to think about how raven parents cope with a workload like that.

//Helena