Film team and scary cameras

Today a team from the Swedish television programme "Mitt i naturen" visited the station. The ravens will share their space on air with wolverines and vultures - illustrating the theme: scavengers. Strictly speaking, ravens are not scavangers at all, but omnivores like humans, although a fair amount of their diet consist of carcasses - especially during winter.

This was really the first "happening" in several months for the ravens who have had vacation following the breeding season, so they were not too happy about the unfamiliar visitors and their huge cameras.

Photographer Daniel is setting up his huge camera.

The film team was nice and patient so I think they managed to get the footage needed. This is however not the first time this particular tv-programme visits - in 2011 almost a whole programme was dedicated to ravens. Back then, they were more than happy pose in front of the cameras, try to eat the microphones AND the programme host. Not so surprising, as they were playful juveniles at the time.

Programme host Martin Emtenäs back in 2011.

Mathias and Anders Lundin, one of the current programme hosts.

The show will air some time this autumn!

//Helena

New paper on tool using crows

Ivo with one of the crows at Auguste von Bayern's lab.

Recently our group published a paper on novel tool-use mode in animals together with Auguste von Bayern from Max Planck Institute for Ornithology/University of Oxford.

Busy with another study, lead author Ivo Jacobs noticed a unique behaviour in a group of captive New Caledonian crows; he saw how one individual slipped a wooden stick into a metal nut and flew off, carrying away both the tool and the object. This and five successive occasion of tool transport resulted in the paper: "A novel tool-use mode in animals: New Caledonian crows insert tools to transport objects", published in Animal Cognition last week.

Abstract:

New Caledonian crows (Corvus moneduloides) rely heavily on a range of tools to extract prey. They manufacture novel tools, save tools for later use, and have morphological features that facilitate tool use. We report six observations, in two individuals, of a novel tool-use mode not previously reported in non-human animals. Insert-and-transport tool use involves inserting a stick into an object and then moving away, thereby transporting both object and tool. All transported objects were non-food objects. One subject used a stick to transport an object that was too large to be handled by beak, which suggests the tool facilitated object control. The function in the other cases is unclear but seems to be an expression of play or exploration. Further studies should investigate whether it is adaptive in the wild and to what extent crows can flexibly apply the behaviour in experimental settings when purposive transportation of objects is advantageous.

A few days ago, New Scientist picked up the news and published a nice article.

//Helena

New lookout points

Summer is low season for research at our station, due to breeding followed by moulting and human holidays. Usually we seize the opportunity to do some maintanance or improvements of the aviaries. Siden and Juno didn't try for a second brood of chicks, so today I put up some new branches in their aviary.

Apart from being extremely curious, Siden and Juno are also very calm when it comes to visitors and doing stuff in their aviary, so instead of watching from a distance they are eager helpers.

Meaning sitting on the branches at the same time as I try to attach them from my ladder. Of course this makes it at bit more of a challange...but when you think of it - how many can boast about selfies with a raven four metres up in the air?

But even if the new perches are fun, they cannot beat my winterjacket - all ravens' favourite - with loads of pockets to be turned inside out. No attention paid to the fact that the one wearing it is clinging to a ladder with all hands and arms busy.

//Helena

Board visit

Today the faculty board (Humanities and Theology) visited the station. The schedule was tight, but we managed a presentation of the station and our research, a chat with the ravens and a nice lunch provided by the visitors!

//Helena

Night roost

All chicks fledged last week and are now trying out all the new branches. This is where they all sleep.

5 weeks old

The chicks are now around 5 weeks old and I try to get them on film, despite their suspicious mother. This is what they look like most of the time, when the weather is sunny - regulating the heat with open beaks. But in a week or so we expect them to start taking little walks outside the nest, exploring their surroundings before it is time to fledge.

//Helena

Broad media interest

Our recent study on corvid cognition has recieved much attention from media during the last few days. Watch the interview with Can Kabadayi, PhD-student and one of the lead authors from our group:

 

A  nice summary of the study can be found at Huffington post.

//Helena

New paper on corvid cognition

Yesterday a new paper (Can Cabadayi et. al) from our group in collaboration with University of Oxford and Max Planck Institute for Ornithology was published in Royal Society Open Science. 

The study: "Ravens, New Caledonian crows and jackdaws parallel great apes in motor self-regulation despite smaller brains" provide evidence that crow birds share similar fundamental cognitive mechanisms with great apes.

Recently, MacLean et al. (MacLean et al. 2014 ) conducted a large-scale study involving 36 species, comparing motor self-regulation across taxa - concluding that absolute brain size predicts level of performance. The great apes were most successful, and only a few of the species tested were birds. Given birds' small brain size—in absolute terms—yet flexible behaviour, their motor self-regulation called for closer study.
As corvids exhibit some of the largest relative avian brain sizes—although small in absolute measure—as well as the most flexible cognition in the animal kingdom, we therefore tested ravens, New Caledonian crows and jackdaws in the so-called cylinder task.

The results showed that the performance of the crow birds was indistinguishable from that of great apes despite the much smaller brains, and that both absolute and relative brain volume to be a reliable predictor of performance within Aves.

Birds are dinousaurs

 A velociraptor skeleton downscaled to half it's size.

Today and yesterday saw the annual visit from the Biology deparment's course in Ecology of behaviour/ethology.
Since the course coincides with the breeding season and the students cannot work with the ravens,  the focus is rather on lectures and ongoing research. This time Ivo and Katarzyna presented their research after Mathias' introductury lecture on bird descent and cognition.

A replica of a Confuciusornis (the earliest known beaked bird) fossil.

A replica of a Tyrannosaurus' foot

Duvis shed some live input on the lecture.

Since the ravens are quite happy as long as nobody goes to close to the nest, the students also got a brief glimpse of some contemporary dinosours. None and Rickard fluffed up a bit, but not more than that.

The chicks are also clearly visible from the outside, but they look mostly like drooping tulips as they sleepily stick their heads in the air or hang over the edge of the nest.

//Helena

Unsuccessful breeding

Siden and Juno has been breeding successfully for three years in a row, raising between 3-5 chicks. However, this year something went wrong and in the middle of last week we understood that the chicks were dead. I had heard at least two chicks for a few days and the parents behaved normally, so we anticipate that there was something wrong with them. Siden and Juno immediately started to work with the nest interior, so maybe they will try a second time. But I can imagine it will take some time to produce new eggs and then it might be too late.

As the empty nest turned off all parental aggression  I decided to take advantage of the tranquility to do some weeding. Weeding might seem like an unnecessary thing to do in an outdoor aviary, but if not done - the weed totally takes over and reduces the ground area for the ravens who really like to spend much time digging and caching.

 Of course I got a lot of help, and Siden and Juno spent most of the time sitting on my back as I struggled with the long roots. 

None and Rickard are a bit more relaxed when I come in their aviary, despite a full nest, as long as I keep to the far end of the aviary. So I keep my part of the bargain which makes it possible for me to clean their tub without quarrel. Especially if I bring some goodies for their babies. So today I even dared some weeding around their bath tub.

Rickard's and None's chicks are now around 3 weeks old and there are five of them. Not three that I first thought. At some point there were even six live chicks, but we actually witnessed None carrying a dead chick from the nest and then fed the others with it.  But I guess five chicks are a handful, and in the wild the number of chicks that makes it to fledging probably are less than in captivity.

//Helena

Hatching next door

Today it was the neighbour's turn. I heard the chirps even before I entered the aviary, and as I did, Juno flew closely past my head to tell me not to come too close. It is interesting how the defense mode is switched on the minute the chicks hatch - some days ago she readily came down to feed, sitting on my arm. This state lasts during the chicks' period in the nest, and some time after fledging, then the parents happily welcome us into their territory again.
Now six weeks of hard work begins; feeding, sheltering and keeping clean to make sure that as many chicks as possible reach fledging.

//Helena

Bathing

Rickard's and None's chicks are now one week old, and so far I have seen three little heads already turning downy grey. The weather has been very mild for some time and I can imagine it getting quite warm on the nest. The ravens love bathing in almost any weather, except wind and rain, so when I changed the tubs today, None - mother-of-three - was the first to dive in.

In the adjacent aviary Embla and Tosta waited for their turn, and Embla made sure she would get in first.

Embla waiting for the tub to fill up.

//Helena

New life

Yesterday was the first day we could expect None's and Rickard's eggs to hatch, but in the afternoon the nest still only housed the beautiful turquoise eggs. This morning, however, I heard the familiar sound of newly hatched ravens, although I am unsure of how many. 

I didn't want to upset the parents by getting to close to the nest so I settle for a picture from last year, April 13h, when None's and Rickard's first chicks were about 2 days old.

 Welcome to the world, little things!

None feeding her first chicks in 2015.

//Helena

Next female on the nest

None has been laying eggs since the 8th of March, and today  - March 18th - I think Juno might have laid her first. Quite similar to the other years it seems: March 19th (2015) March 10th (2014) and March 22nd (2013). She did come down to feed, though, and found the tip of my boot appropriate as feeding spot. Usually the ravens grab a piece of meat with their beaks, stand on it with one foot, and tear pieces of it - and of course you wouldn't want to do that on the ground, risking getting dirt in your mouth.

Juno on my boot

I consider myself lucky to be able to follow the daily life of a raven from such close a distance. Of course our ravens live a different life from the wild ravens, but I believe most of the behaviour is still the same. The aviaries are situated in a good spot when it comes to social life it seems. Many times every day, wild ravens or other interesting birds are passing, and our ravens spend much time patrolling their territories, claiming their aviaries with dominant calls and chasing off intruders if necessary. The two utmost aviaries have almost 270 degrees vision and the ravens spot airplanes, birds of prey and other birds so much quicker than we do. Sometimes eagles are passing, and without exception it as always the ravens telling me about it - long before I have the chance to conjure up a species from the litte black dot in the sky.

Still the parents to be, happily greets me entering the aviaries, but as soon as the chicks start to hatch, they grow more protective and aggressive - even if it is not personal. So I enjoy my moments in the sun with these intense, loving and beautiful creatures.

Siden says hello.

//Helena

It has begun

None on the nest (in poor photo quality)

The egg-laying, that is - for None and Rickard. It started already two days ago, on the 8th of March, with None spending longer periods in the nest. Last year this happened on March 23th, so this is two weeks earlier. Siden and Juno seems to be a bit later, and are still happy to spend time with us when we are in the aviary.

We don't know yet if there are any eggs, and this aftenoon None took some time off from the egg-laying, preening on a high perch.

As soon as she left the nest, Rickard positioned himself as egg-guard in the doorway (to the right).

Last year, I kept feeding None and Rickard from inside of the experiment room, to get a glimpse of - and also to take pictures - of the chicks as they developed. But I am not sure that I will do that this year, as the parents do not particularly like it.

//Helena

Early birds?

Last year Rickard and None shocked us by all of a sudden building a nest in one of the experiment compartments. This was mid March. Then last Friday I noticed that all twigs and branches in the aviary was gone, and when I looked up, I saw this - almost one month early!

Today when I was running some tests on Rickard in the outdoor experiment area, he was only interested in gathering small pieces of lining anad dried grass. So I had to give him some time alone, let him back in with None and the nest, and then ask him to come back for the experiment. And once all the lining material was gone, it worked fine.

Usually the horses have started to loose their coat when the ravens are nesting, but this year it is so early that they have to make do with my home made strings of jute.

A bit afraid of the phone at first.

Getting closer.

Rickard was the most daring, and flew off wtih a mouthfull.

//Helena

Snowbathing

Tosta and Embla bathes in the snow.

Busy, busy days

Breeding season is coming up and there is so much to do! Once the females are on the nest we cannot work with the pairs until the chicks have fledged - a period of about 4 months. Another thing we wanted to do before breeding was to divide the largest aviary, housing the pair Rickard and None and the two females Embla and Tosta, so all birds get equally big space during breeding season. Once the courting behaviour starts we separate the breeders from the non-breeders to avoid any aggression.
At the same time we have been sprinting to end the experiments - a long-term planning study and a study on string-pulling involving all six birds - so it has been difficult to decide when to start the new construction.
However, as our birds are older and more used to different things the construction work went surprisingly smooth, and the ravens were happy to try out the new shelves and branches only after a day or two. The young females Tosta and Embla were also content with the new part and are separated from Rickard and None from now on. Hopefully we will be able to let them together again when autumn comes, but as ravens are territorial birds once they form pairs, we will have to wait and see.

//Helena