Recently it has been discovered that Black Larks, living on the Eurasian steppes in Kazakhstan, transport dung to their nests to build large 'pavements' . Weird and almost dirty behaviour, but what is the use of it? This spring a team of researchers from the Universities of Wageningen and Münster and the Association for the Conservation of Biodiversity in Kazakhstan (ACBK) will try to answer this question, doing fieldwork in the Korgalzhyn area in Kazakhstan. On this blog we will post on our findings and adventures.

Sunday, 26 May 2013

Clay cookies

With two experiments already running, we are now making a headstart with the trampling experiment. With this experiment we want to test the hypothesis that cattle do not step in their own dung while grazing. For Black Larks this would mean that using dung around their nest would reduce the chance that their nest is being trampled. For the experiment we will slowly herd a group of cattle trough an area in which we placed fake nests, which are places either in dung piles or on bare soil.

For the fake nests we were planning to use small balls or eggs, made out of papier maché, as we showed in one of the earlier blog posts. Strong wind is however a constant factor here on the steppe, and these fake eggs would probably quickly fly off as soon as we would put them on the ground. Therefore we thought of a different material for fake nests, namely clay! Yesterday we moulded 200+ clay ‘cookies’ more or less the size of a Black Lark nest. We baked them at 35 degrees on the car for about two hours and now they are ready to use!

Making the cookies

Drying them on the car, 220 in total

This Greater Spotted Eagle flew over our heads. It's a late migrant or a rare summer visitor.

Wednesday, 22 May 2013

Being a good mother in changeable weather

The weather is rather changeable, now we have windforce 6-7 and sometimes rain and yesterday we still had nightfrost. However, we also had quite warm days. Higher temperatures are beneficial for the Black Larks, however, the anti-kamari (insect repellent) is then very much needed! But no complaints as we now have 69 nests! The finding strategy has slightly changed now. Before we flushed females with the car by driving over the steppe and steppe tracks. Now we regularly find males and females with insects in their bill, a clear sign that they are feeding their chicks. In a matter of time they will fly to their nest and take off without food. Then the nest is rather easily found. With more and more nests having chicks, the number of successful nests are also increasing. For us, a nest is successful when the chicks have left the nest. We are unfortunately unable to see whether chicks survive leave the nest.

In an earlier blog post we wrote about the Ibuttons (temperature loggers) in the nest while the female is incubating. This is doing fine now and we have put loggers in 28 nests. We already see nice incubation patterns, but also strange things. For example in the morning of 12 May there was heavy rain. During the rain all the females stayed on the nest (good parenting). After the rain, when the females must have been soaked, all birds with loggers left the nest for about 1.5 hours! The need for foraging apparently was very high. During normal days we see different strategies. Some birds leave the nest for a long period in the early morning and in the evening, some birds only leave the nest for shorter periods. Very interesting stuff to look into!

Another way to see whether dung is beneficial for the microclimate we have put 12 loggers inside left (predated or successful) nests and 12 loggers just 30 cm outside the nest. In this way we see how the microclimate differs between the cups and a random spot outside the nest. Preliminary results are that the minimum temperature is about 2 degrees higher in nests than outside the nest and the maximum temperature is 7 degrees lower in the nests. Both is beneficial for the female, eggs and chicks. We do not know the main cause behind this buffering effect yet.

Then a short note on the other things than Black Larks. We keep our eyes open during the fieldwork and afterwards. In this way we found Caspian Plovers on migration (rather scarce here), many many White-winged Terns and Little Stints and the Ruffs are becoming very numerous. Also, there is a nice group (approx. 300 ind) of Rosy Starlings around the village. The most stunning bird we saw was a male Crested Honey-buzzard on the 16th, which was only the second record for this area or more to say Central Kazakhstan. More to follow soon!

We can imagine that people are also interested in how the non-project things happen. Well, we all stay in so called homestays, so at home with locals. Here, we are adopted as family and provided with good local food and the occasional banja (sauna). Thomas and Thijs are living together with Timur and Ruslan. Ruslan is the project coordinator on Sociable Lapwings (ACBK), from which we get much assistance on logistics and information about the use of dung in Sociable Lapwings. Timur also works for the Sociable Lapwing project and also works at the Korgalzhyn Nature Reserve. Gera is staying in another homestay with Boris, who works at the Korgalzhyn Nature Reserve and there a lot people from the Sociable Lapwing project stay for one or few days. 

Nest attendance of one nest during one day (12th of May). In the morning she leaves  the nest for a long time (after the rain), in the afternoon she leaves the nest for only short periods. To get through the night, she leaves the nest again for a long period before the sun sets. 

Group of Rosy Starlings in the garden of the place where Gera stays

Lunch in the field!
We are still happy :)

Adult male Crested Honey-Buzzard

Monday, 13 May 2013

Already at 50% of the target

We first want to kick of with the good news: we already found 49 nests and with 100 being the target this is almost the half. However, nest finding becomes harder and harder as the vegetation grows very quickly and the temperatures are in general rising. In general, because we unfortunately lost three nests due to frost in the night, very sad but it happens. The females of these nests will try it one or two more times. The same holds for all the nests that are predated, which is very common. About 50% of the nests are currently predated and we haven't had a succesfull nest yet, but that might be expected tomorrow. This is somewhat later than usual, but this year is an unusual wet and cold year.

We have two main study areas around Korgalzhyn and it means that we drive for about 80 kilometers over the steppe tracks each day, the scale is quite coarse here. We have an old Soviet state farm map where all tracks are drawn. It looks like a normal agricultural infrastructure, however the fields are 3 by 3 kilometers large. We use a Lada Niva from the ACBK for our fieldwork, a great car for the steppe! Although we sometimes have to tweak it a bit to make it work, it does a great job on the bumpy field rides.

A few days ago we dug 80 pitfalls in the two study areas. We do this to see if the dung around the nest is collected is beneficial to the amount of insects (mainly beetles) around the nest. If this is the case, females don't need to leave the nest for a long time and far distance to (shortly) feed. Therefore we paired the pitfals: one in a existing dung pile and one 5 meters away from that dung pile in the bare soil. In 2 weeks we will collect the pitfalls and count, indentify and weigh the insects.

And then, we are not always in the field and sometimes we are unable to go onto the steppe due to rain. In that case we spent some time birdwatching in the village or the near surroundings. Currently the Siberian Chiffchafs are replaced by Greenish Warblers (very numerous) and we see many many Lesser Whitethroats. Already for a few days there is massive migration of White-winged Terns and we had one day of massive migration of Black-winged Pratincoles. Everything is a bit late, but that doesn't matter to us, we have the time. This morning we saw one of the predators of the nests: a steppe polecat, we often see foxes as well. We also see many birds of prey, mainly Pallid Harriers, but also quite a few Short-eared Owls and sometimes Steppe Eagles. This year seems to be a good year for voles, which is good for the harriers and owls.

Male Black Lark

Chicks of about 6 days old

Female stays on the nest for only the last moment. When she flies of she will try to fool us by pretending if she is hurt. Just like many waders.

Tulips make place for Lillies. In the background our Lada Niva

Pallid Harrier, photographed from the car at 40 km/ph. It seemed to play with us!

Sunday, 5 May 2013

First week

Nest searching (and finding) has started! This week we all arrived in the village of Korgalzhyn, right in the middle of the Kazakh steppe and the Black Lark’s breeding area. We directly started of finding nests, since the Black Lark breeding season has already started. To the steppe!

The steppe is often described as an endless sea of grass, which implies that it is very monotone. Although endless, the steppe is far from monotone. Currently the wild tulips are flowering and color the steppe with yellow, white and pink flowers. Orange tulips are rare and finding one will bring happiness for the rest of your life! We already found some orange ones, we hope this will give us luck in finding nests.
Black Larks are ground breeders and make deep cup-shaped nests (7 cm deep) in small scrapes in the soil. These nests are often located next to tufts of grass. The female scrapes out the nest, then adds small pieces of grass as lining. Often she adds pieces of dung as a pavement. During this study we want to find out why the birds do that.

Finding the nests is a time consuming business. In an old Lada Niva, we drive across tracks over the steppe. Black Larks often nest close to these tracks, and by driving we hope to flush the females from their nests. When a female flies off, we start looking for the nest on the spot she flew off. Sometimes we indeed flushed her from the nest and the nest is quickly found, but often she was either foraging or doing something else and finding the nest requires a bit more luck. So far we have found 22 nests with eggs and 13 nests which were still in the building phase. These latter nests might be used, but the birds might also decide to build a new nest somewhere else.

Once we find a nest we note down the location, the number of eggs, and data on the surrounding vegetation. Also we count the number of dung pellets and the direction in which the dung pavement is build. Dung might help to protect the nest against cold wind. If dung buffers the nest against the cold, this might have effect on the time a female can be off the eggs to feed. For this reason we want to keep track for how long the female leaves the nest in between incubation. We measure this using temperature loggers placed in the nest. We modified Ibuttons (as you can read in our last blog post) to fit on nails. We push a nail trough the nest into the soil and put the Ibutton on the nail with Velcro. In this way the Ibuttons fit snuggly on the bottom of the nest and the bird is unable to remove them. 
Next to black Larks we keep our eyes open for other birds. Bird migration is still in full swing, with hundreds of Yellow Wagtails (subsp. beema) and large numbers of others birds, including one of the largest fall in recent years (according to the local birders) of Lesser Whitethroats , Siberian Chiffchaffs, Common Redstarts and Wrynecks.

Female Black Lark

Demoiselle Crane

Eurasian Wryneck

How the buttons fit in the nest. We now fit the buttons under the lining

Huge fields of wild Tulips

Huge fields of wild Tulips

Enjoying free time