Nest NLLI-482 is located on top of a small and old  river dune in the Zaarderheiken Woods between Floriade and Venlo. I discovered the nest in 2001, hidden under a mound of branches. Today we visited this nest, although the weather was cold and in the shadow was some unmelted snow. The old branches are now consumed by the wood ants and the nest is on a sunny slope catching sunlight.  The ants took their advantage and came out to take a sunbath. (View the movie).

The ant mounds are so constructed that the temperature inside keeps warm enough for the ants to survive the winter. In winter you can find holes inside and around these nests. They are created by woodpeckers, fouraging on wood ants. But the hole in this nest is special. However the wood ant mound shrunk a little last year, the branches prevent the top from falling down. So a little space was saved between the top of the ant nest and the top of the structure. Inside this hole we discovered tracks from an other animal. On this high-res photo you can discover all kind of material inside this nest.

What kind of animal would live inside a wood ant nest. A mice family? Or a squirrel?

Today was the start of the brand new wood-ant season 2010. Last two years the fieldwork was already improved a lot. When documenting a nest observation the GPS coordinates are added to the observation-sheet. Another big improvement is taking photo’s from each nest. Today we went to the Zaarderheiken-site to check out some nests. At first, we had to take the GPS coordinates and nest dimentions for each nest. But our goal was to test the new piquets in several ways.

The first test was placing four piquets around a nest with scale markings. These piquets are vissible on the photo’s and  make it possible to read the nests dimentions from the photo later. The second test was using them during the exploration of a new site. We marked all the nests we discovered. Once finished we had a clear overview from a central position. The third test was marking a fictional ant road (because in winter there are no ant-roads). The piquets were placed on this fictional trail between three nests. This method will be used later this year when several super-colonies will be mapped.

You can read more about the fieldwork here: camera, GPS , piquets and data integrity

Walking through the woods and the fields you maybe see them walking: ants. It can be a single ant, but also ants walking the same route. These ant-roads can be several meters wide or just some centimeters. The roads start in the ant nest and go to a tree, another nest or some kind of food source like a dead animal.

Many ants that create roads are from the Formicinae sub-family. This family contains the Lasius and the Formica Genus. Both are very common in the Dutch landscape. Lasius niger for example creates short connections between nest entrances in the pavement. Lasius fuliginosus, who live in hollow trees create nice roads to a single food source. And when they are finished they make a new road to a new source. These roads can be 50 or 60 meters long.

But the best road builders are Formica rufa and Formica polyctena. They build realy large connections between trees or other ant nests, sometimes with trees to cross small stream. These roads stand for many years and can be compared with ancient Roman roads. Here you see some maps of these road structures. Sometimes these roads are so old that they are almost tunnels, covered with lichens and moss, in a straight line from nest to destination. So the ants are protected against weather and enemies. Realy great to see them in Boswachterij Odoorn, just minutes from the sheep fold.

Last week the sites in the region Emmen are revisited. There are large populations of red wood ants at several sites, but at three of the sites wildfires destroyed large heathlands. The fires were caused by an arsonists.

Several nests were in or at the edge of the fire, but because only heatlands were hit the fire was not severe enough to destoy nests. One example is nest Emmerdennen-3, wich was in the fire. But after a short examination it was clear that the ants rebuild the nest. A smaller nest, about 100 meters away, was hit worse. Emmerdennen-6 is a small nest, close to a more severe fire. But the survivibg ants are moving their eggs to a new nestlocation. The fire harmed their nest, but created a much more suitable place three meters away. More severe fire was at the Kampervenen-17 nest. One nest was in the middle of it, but also here there are surviving ants building a new nest. The largest fire was on the Molenveld near Exloo. One nest, MD-8, on the edge is recovered from the fire.

It seems that wildfires on heathlands are not severe enough to destroy complete wood ant populations. The nests seen last week are all recovered, or the ants are building a new nests. These nests go deep underground, probably deep enough to protect the ants against heat and smoke. But what is very interesting is that these ants did also find a way to keep oxigen inside the nest. Did they close the many entrances to the nest before the fire arrived? Two interesing observations were also that wood ants use carbonized materials to rebuild the nest, even while there is fresh matrial available. The other observation is that wildfires also create new opportunities for ants, like Emmerdennen 7. Even when un burned sites are available, the ants chose a brand new location to build their new home.

Beside these wildfire observations there are 145 new photo’s and 185 nest observations added to the database. About 70 new nests were discovered. The updates are available at: Bargeres, Emmerdennen, Emmerschans, Hunzebos, Kampenvenen, Molenveld, Noordbargerbosch, Schuttersbosje and Valtherbos

Earlier this week I published some ant-road maps on Ant-maps.com. One of these maps shows the nest and ant-path structure from the supre colonie ‘Ravensheide 1′. The structure counted at least 18 nest, including some nest one meter high. Some protected by metal cages to protect the nest against hungry woodpeckers.

Last year some of the nest were disapeared or a lot smaller than before. And today, when I visited the colonie all the nest were gone. Not one was active. Two new nest had been formed in the last 16 months, but even these ‘new’ nest were nothing more than a ruin. Only on one spot, now marked with the project-number Ravensheide-323, counted some ants… but no nest. That means some ants found a save place under the ground. Where did all the other ants go?

Here you find a full list of Ravensheide.

Digging in the notes from the last 16 years I found sites that I did not add to ant-maps yet. One site is the Leudal, close to Roermond. Two others are The Borkeld and Herikerberg close to Markelo. The notes were taken without any knowledge of the site. The proportions of the simple maps are bad that it is impossible to find out where these nest were. Even with the help of Google Earth, that shows a lot of details I recognize.

So, this is a lesson for me and for anyone else who want to make notes in the field: do not think you can recover important locations or details later. You probably can’t.

You can find some tips and information about the notes from the field here.