Antroducing: the dune ants of the Danube delta (Myrmica deplanata)

The beautiful Danube delta starts at the Romanian city of Tulcea. From there a ferry goes all the way to Sfantu Gheorghe at the coast of the Black Sea. We got on about halfway at Mahmudia, as far a you could (comfortably) go by car, but it still took almost four hours to get to our destination. Plenty of time to enjoy the nature along the way (and this being the only way to get there, is probably also why there still is so much nature left to enjoy).

I love sights like these: various trees forming a motley 'wall of green'.

Past endless fields of reeds interspersed with big willows leaning over the river from the swampy river banks, silvery birches and tall poplars behind them. A beautiful place and great for spotting birds, but absolutely terrible for ants. So Kittenmancer's brother got to play with his telelens, photographing seagulls and cormorants, and I got a break from constantly looking around my feet for scurrying insects.

I was saving myself for the dune area behind the beach. This location, with its sparse vegetation, save for some hardy grasses and the occasional stubborn shrubbery, was likely going to be a good location for finding Formica species, swiftly running across the sand.

However, what we found instead were Myrmicas, lots of them. They were larger than the workers belonging to our Queen of Buttons at home and they were so dark red, it was almost black. These ants were hard to miss, busy trails crossing the sandy hiking paths, hundreds of them moving from their nests under the brushes into the grasses on the other side where they scattered. What they were doing? Why does the chicken ant cross the road?

It could have been they were waging war on their neighbours. Many of these workers were scarred from battle, missing an antenna or a leg. A few were even 'wearing' small dead ants, mandibles locked in a firm deathgrip on various appendages like some rather inconvenient badge of honour. Opposed to the larger Myrmicas, smaller ones were easily identified: Tetramorium caespitum, little war-mongers as they are.

The path through the dunes to the beach. It looks a lot greener from above.

We crossed several of these outgoing trails on our way to the beach and pointed them out to Kittenmancer's 5-year-old nephew (we were spending our holiday with his parents). Increasingly anthusiastic, he required some convincing not to touch these particular 'furnici', because Myrmicas typically back up their aggressive temper with a nasty sting. Our little sidekick was right though: strutting around in all their dark shiny glory, these beauties just were just begging to be picked up. You just need proper tools, starting with a spade and a box.

So after we came back to dig out the ninja-ants the next afternoon, we wanted to return to the first location where we saw the Myrmicas. This turned into what we thought was the second location and then even on to the third. It proved to be actually quite tricky to find them now all the ants were hiding back in their nests, because the entrances were hard to distinguish from the abundance of small holes on the sides of the path. These belonged to the many predatory wasps laying claim to most of the sandy real estate. We had to walk all the way back to the beach for the only ant trail we found next to a clear landmark: human garbage containers.

We figured this was going to be easier than with the smaller ants we dug up an hour earlier from an unyielding mix of hardened clay and rubble. Now we had loose sand and if we just dug around the clump of Marram Grass the ants were nesting under was under we could just pull that out and shake it to separate the colony from the roots. This plan worked pretty well, except for the part that we were only finding only workers, walking around in a surprisingly calm manner.

The problem was that while Myrmica's are usually polygynous, those are typically larger colonies. Additionally, a queen of this genus is only slightly bigger than their average worker ant. The best way to recognize them is looking for any ant with a larger thorax: example. We might also have come too late in the season, or were digging in the wrong location for any brood (and thus queens who were likely to be close by).

Close to giving up after about an hour and having dug quite a sizeable hole, we were ecstatic when we finally spotted a queen.. I think this was a bit of a turning point in our trip, hooking up on the euphoria of successfully digging up a colony (and teaching us that perseverance is key).

Wranging ants on the bed in the hotel: a common activity during this holiday.

Back at the hotel we found out that even though the Myrmicas enjoyed the cotton soaked in some sugary 'fruit' beverage we primarily bought for its convenient glass bottle, they defnitely didn't like their temporary housing. Digging a dozen tunnels in only a few spoonfuls of dirt and constant escape attempts every time we had to open the box (the snappy lid would also collapse any architecture).

Because we didn't have any brood, and several dead died overnight, we went to collect some additional workers the next day, bringing up their total to about a hundred. We decided to move them into the glass jar containing soaked cotton and crumpled toilet paper to provide a higher humidity and a more comfortable nesting environment. Though this meant wrangling them almost one by one through the small opening, while containing the ones already inside and keeping an eye on the ones still (not) waiting in their old box.

On top of this all, these vicious little fighters would bite on our brushes and then decide to not let go for the next fifteen minutes. It usually required a second brush and a surprising amount of force to shove them off (sometimes they would then be simply stuck on the second brush instead).

Death to the hairy invader! Bite, sting, bite some more!

The Myrmicas seemed reasonable happy and comfortable during the next week when we traveled to our second location: an off-season ski resort high in the Carpathian mountains. However, the toilet paper was starting to become problematic. The workers had been shredding it to the point where the bottom half looked like a big fuzz. Which, combined with the high humidity and temperature was moulding and we were finding dead workers again. Luckily, by then we had managed to get our hands on some proper test tubes, so we could provide them with more reliable temporary housing.

But while the environment might be more easily controlled in a smaller test tube, a colony of this size is definitely not. This inevitably resulted in a big escape during the second week when we tried to replace the dried-out cotton swap containing the fruity drink they were feeding on. The agitated ants were impossible to contain in a single tube: put one caught worker in, two more escape. So we ended up splitting up the colony over two tubes.

Not an ideal situation because the unique pheromones ants use to identify themselves will change over time to the point where a colony will no longer recognize and kill separated sisters. We figured this wouldn't happen before we could get home, but already the next day the Myrmica queen decided to do something stupid, forcing yet another relocation.

Because we had to use the cotton from folded make-up discs as the water barrier in the tube, the queen had found a nice crevice to hide herself in. Typical queen behaviour, only this time she had managed to get herself stuck! Splayed between the wet cotton and the glass, she was unable to wriggle herself free and the panicking workers couldn't pull her out by her hind legs either. So we had to go in and rescue her from slow suffocation and the more immediate threat of accidental dismemberment by the good intentions of her frantic family, all while trying to contain the rest of the colony.

Ugh, fine! Back into your old bottle! Surely a mould hazard, but at least the fresh toilet paper would provide the Myrmicas enough of a maze to reduce the escape pressure during colony transfer. Besides, they seemed to like that place better anyway. While transferring the workers was a lot easier this time, saving their queen turned into tense surgical operation of pulling out the cotton from halfway the narrow test tube without crushing her against the glass.

The queen saved, hiding near my thumb.

Sounds all like a lot of work? Well it wasn't as if we weren't already busy when we noticed the queen's predicament. Kittenmancer and I were actually right in the middle of moving a Formica cunicularia colony we freshly caught into a bottle of their own. And these very quick ants were causing plenty of trouble, escaping their box and running all over the bed with us trying to scoop them into test tubes. Ofcourse: chaos + emergency = mistakes.

Like accidentally putting a Myrmica into a test tube already containing a dozen Formicas. When we noticed the mistake, the Myrmica was already succumbing to her wounds, but not after having killed three of the larger Formica workers and scaring off the rest cowering at the far end of the tube.

Or I mistakenly emptied a tube with a dozen Formicas into the wrong bottle. Several got killed almost instantly by the ferocious fighters, agitated by the relocation. But luckily most managed to escape by running round and round the hostile bottle (they really are that quick). It was interesting and gruesome to then witness the Myrmicas cutting off the (much larger) gasters of their victims as nutritious trophies.

Gaster 'jars' found after we later moved the Myrmicas out of their bottle.

A few more days, a few more days, a few more days... We were getting increasingly antsy about having to rely on improvised tools and half-measures, trying to keep all the ants happy and alive (up to six colonies and several loose queens by then). Luckily we managed to get home without any more incidents, save for one funny one where we caught a huge grasshopper and fed it to our ants. The Myrmicas got the thorax part with the smaller legs (though still several times the length of a worker), which were, through some weird biology of insects were still moving. These legs being the only parts the ants could effectively bite they ended being swung about in the air like some bizarre rollercoaster attraction.

An astute reader might notice that so far I haven't mentioned the actual name of these Myrmicas yet. First off, it took us a week days to come up with a nice name for the queen. We ended up named her Dobrogea after the region containing the Danube delta. But finding the actual name of the species took a lot longer still.

Where the problem with the Georgies was that I didn't find fitting candidates, our big dark beauties from the dunes had too many. AntWiki does provide a very nice identification key to the Myrmicas specific to Romania (courtesy of a bunch of Bulgarian and Hungarian entomologists), but determining features like the distance between the antenna sockets on the head (the 'frons'), or the shape of the knots between the thorax and the gaster (petiole and postpetiole), require some serious magnification.

So, when we finally got home, and after Kittenmancer got me some more magnification, I managed to identify our Myrmicas from the Danube delta's dunes as Myrmica deplanata. Their description as 'one of the most thermo-xerophilous species of the genus Myrmica' definitely fits their behaviour like a glove. And, being a rare species (not a single of the two dozen online ant retailers in Europe even mentions them), makes Kittenmancer and me quite lucky ant-keepers.

Big tummies to fit all the well-deserved yummy after a long trip to they new home.

Ofcourse this means we have to put in extra effort to make Dobrogea and her colony feel at home. So their next update will be about moving them into something more confortable than a mere test tube inside a cheap cheese box (and them not cooperating in the slightest).