False Comma Nympahlis vau-album - showing its white ‘V’. One of Europe’s rarest butterflies!
The False Comma Nymphalis vau-album (or Compton’s Tortoiseshell, as it is known in North America) has always been a scarce butterfly on the western limit of its range in Europe. In recent years it has become even more so, and is considered extinct in Austria, Czech Republic, Estonia, Hungary, Slovenia and Slovakia. However, it seems to be holding its own in the mountains of southeast Serbia and a number of butterfly tour companies now target this spectacular nymphalid. I was privileged to join my friend János Oláh’s 2025 Sakertours Serbia butterfly watching tour. János applies the same level of determination and planning to finding rare butterflies as he does to birds and we had a fantastic time, recording 110 species in five full days including some very sought after ones. As well as False Comma, in this small corner of Serbia, near the Bulgarian border, we also saw: Yellow-banded Skipper Pyrgus sidae; Apollo Parnassius apollo; Violet Copper Lycaenea helle (among seven species of copper!); Blue Argus Aricia anteros; Bog Fritillary Boloria eunomia (among seventeen species of fritillary); Poplar Admiral Limentis populi (four, of the all dark form tremulae, prevalent in the Balkans); the enigmatic Lesser Lattice Brown Kirinia climene; Russian Heath Coenonympha leander; Bulgarian Ringlet Erebia orientalis and Almond-eyed Ringlet Erebia albergana, to mention a few.
This False Comma has a small notch in its left wing and was easily identified as the same individual.
János has done a lot of testing over the last few years, checking the optimum timing for this tour and he concluded that 11 June was a good start date for freshly emerged butterflies of a wide range of species hopefully including False Comma at the beginning of its season. However, after one of the coldest springs on record in eastern Europe this year we were nervous that we might be too early this time. We need not have worried; it seemed that the recent warm weather just before the tour start had got things back on track for some normal flight timings. There are zillions of waypoints available online for previous sightings of False Comma, but it is a mobile butterfly, so it pays to know some of its favourite spots. There is much else to see in this part of Serbia and János promised all the other butterflies as well, so we did not devote 100% of our time to searching for False Comma. There is evidence that it is mostly active in Serbia between 8.30AM and 12PM in warm conditions in June/July, with ‘virtually no activity after midday’ (Gascoigne-Pees et al 2014) and we spent plenty of time in known previous locations around this time. So, we were interested to get a hot tip from Isidor Saric that he had seen one along one of the forest tracks we had walked along a couple of days earlier, but at 3PM. He was spot on with the location though, and, to our delight, it was still present, a few metres from where we started to search! A great bit of spotting by Jasmin, as it flew down from the forest canopy to a tiny ditch behind us.
Easily overlooked on the ground among the debris of the small spring-fed ditch.
The only wet areas of the dirt track were where spring water from uphill appeared at its edge, there had not been any rain recently in what was turning into a prolonged dry spell. We watched it more or less continuously from 1145 to 1303 on 15 June, taking salts, or perched up in the canopy, at around 4-5m from the ground, usually on leaves but a couple of times on a tree trunk. At 790m ASL this sighting was at the lower end of the altitudinal range and well short of the regular 1569m ASL Babin Zub Hotel site. The temperature was around 25 degrees Celsius, and it was noticeable that it only flew to the ground after basking in sunshine. When the sun was occasionally covered by a cloud it remained in the leaves. It also stuck to a stretch of around only 20m, and mostly flew up or down, rather than along the track, so it would be very easy to miss if our walk by did not coincide with one of its visits to the ground, as had presumably happened already. We had seen plenty of other butterflies taking salts along this track, including numerous Commas Polygonia c-album but had drawn a blank with False Comma until now. When taking salts, it could be approached quite closely with care, but it did not like rapid movements. A very special close encounter with one of Europe’s rarest butterflies!
False Comma, taking salts from a trackside ditch.
Its distribution is not limited by the source of food as their caterpillars have quite a wide range of food plants including common birch, willow, poplar and elm species. So, the recent decline in Europe is thought to be climate related. False Commas are thought to have quite specific climate requirements, favouring prolonged and stable sub-zero temperatures during hibernation (in such places as old wood stacks and disused buildings) but they do not do well when early warm spells are followed by severe frosts. When they emerge, they do not seek nectar but other substances including sap and animal excrement. Eggs are laid in shady and damp spots in woodland, not in direct sunlight as with some other nymphs. N. vau-album is also strongly migratory (especially to the east of Europe) and this may have influenced records in eastern Europe but the consistent presence of fresh adults in Serbia means it is certainly breeding there and therefore must be a habitat and climatic sweet spot.
The spectacular False Comma, a life-changing experience for butterfly enthusiasts!
False Comma retreats to the trees when disturbed, or just when it has taken on enough salts.
False Comma keeping an eye on us from the canopy.