Pilot study in Haidlhof

Jorg Massen, senior post-doc (Vienna) and Mathias

The new project "The social intelligence hypothesis and the role of episodic memory" is a collaboration with Thomas Bugnyar at the University of Vienna (Department of Cognitive Biology), and this week we are at the research station at Haidlhof to be part of the project's pilot study.

Designing experimental set-ups for intelligent animals is not an armchair business, which is the reason why it is important to do a pilot study. A pilot study helps to decide on practical matters that no one could foresee in theory, and makes the set-up of the real study more solid and more likely to succeed.

Discussing practicalities with master student Jana Müller and co-workers.

The research station in Haidlhof served as a model when be designed our own research facility, and houses four breeding pairs and a big juvenile group at the moment.

One of the big aviaries with juvenile ravens.

The facility also houses the biggest captive population of keas - meat eating parrots, native to New Zeeland. Read more about the kea lab.

//Helena

Unexpected action

Rickard and None has been an item just as long as Siden and Juno. Right from the beginning, that is. Their relationship has been somewhat more immature, though - maybe due to the fact that they have been the subordinate couple with no territory of their own. Last year, they made no attempt to build a nest, and this year was no exception. Until last week! As they are now the top birds of their group, they control the aviary, which might trigger their breedning behavior. Together with the fact that they turn 4 this spring. Siden and Juno have been breeding successfully since they were 2, which is exceptionally early. Normally, ravens start breeding between 2 and 7 years.
This is nothing we have planned for, and even if they don't succeed this first try, it might cause some unwanted aggression towards the three other young ravens in the group. We have to monitor them closely, and be quick to separate them into two groups, should there be too much tension. However, it is always more tricky to mix two groups after separation since they have to re-establish the hierarchy once they are together again.

One can tell that expericence counts, as thir nest is not as stable and well-knitted as the third-time-breeders' next door.

Experienced or not...they got the lucky-blue-string right...!

When I came out this morning, None was in the nest but did come down to feed. I managed to get a look in the nest, and there is not yet any eggs. I have not seen them mate either, and there are lots of parametres to get right if to succeed, so we will just have to see what happens.

//Helena

Egg-time!

Juno has been in and out of the nest for some days now, but most of the time she and Siden have spent basking in the sun, chasing off intruders or snuggling. But yesterday the periods in the nest grew longer, and now it seems as she is there to stay. So for this year we note March 19th, last year; March 10th and 2013; March 22nd.

One peculiar detail about the nest is the blue string hanging out. I have seen that on several wild nests as well, and when I looked at the picure from last year....

I take it, that it is blue string for luck!

//Helena

New interior

While the ravens are busy courting and building, we take the opportunity to refresh the interior of the aviaries. After the rainy winter, the ground is a muddy mess, and even if the ravens seem to mind less than we do, they are happy about the change. So we ordered a few tons of gravel and a lorry filled with wood chips and rolled up our sleeves.

First, fabric to keep the gravel from sinking and the weed from growing, and then 15 cm of wood chips. The long runway and the experiment room are especially important to keep clean from nettles and grass, since the ravens often cache objects that are part of different experiments. And trying to find these objects in the grass is a bit like finding a needle in a haystack...now we only have to find the needle in the wood chips.

The ravens went crazy over the the wood chips, and started digging ferociously. And of course, they soon learned that there was fabric in the bottom...which in typical crow-bird-way suddenly turned into the most desirable thing.

But when I brought the super-scary-black-camera the photos ended up like this.

//Helena

Sneak peek

The nest box from below.

Siden and Juno has courted each other for several weeks now, but they haven't been particularly interested in the new nest box. Even so, I have provided them with different kind of twigs, if they should feel like trying out the new spot.

So, for the last few days the activity has gone from trying out the odd twig to intense nest construction. It seems as if building the base take the longest time, while forming the middle and top parts goes quicker. Or at least with a higher frequency. Yesterday I went over our neighbour to get some thinner, yet tough, twigs and Siden and Juno just went crazy - spending the whole afternoon carrying twigs to the box, and arranging them inside.

From below, it doesn't really look like anything more than a pile of twigs, and every year I wonder what it looks like from above. So tonight, when Siden and Juno perched outside in the dark aviary, I decided to sneak up the ladder with a camera. The ladder has been standing there ever since I built the new box, but I haven't climbed it since breeding season started. To say that they don't want you to get close to their nest is a grave understatement, and as I had left the light on, they could come inside at any time to see what was going on. I really didn't want to betray their trust.

But I was lucky, and...wow! The blurry, tilted picture doesn't do the architects justice, because the bowl in the middle was so evenly shaped and so neatly knitted that the surface was totally smooth. I could also see patches of wool tucked into it, and it looked...cosy!

Last year, we believe that Juno laid her first egg on March 10th, and a week ago I would never had thought that she might repeat that this year. But know I'm not so sure.

//Helena