Hi Milen!
Thanks very much for your message and confirmation that the species is indeed Cordugaster heros.
I am delighted you have made contact, as I know very well of your important research into the Odonata of Bulgaria and your fantastic website:
http://odonata.biodiversity.bg/index_en.htm
I refer to it a lot for reference and to learn more about Bulgaria's dragonflies.
For the last 20 years I have been exploring Bulgaria's mountains, writing about them as well as guiding and organising walking and wildlife holidays there. I have gathered a huge bank of data on the fauna of Bulgaria, as I have recorded almost every sighting I have made during these years with data about location, altitude and time. The vast majority of my records are birds, herpetofauna and mammals...as these of course have been easier for me to identify. I have seen numerous dragonflies but sadly have as yet little or no experience of identifying them. I will of course be glad to pass on what little data I have, and now I am aware that you are keeping a close record of every sighting in Bulgaria, will do my best to record more information for you during my annual explorations in the Bulgarian mountains. I will also try to take more photos and let you have copies of these, as I am sure you may be able to make some accurate identifications from some of them.
The specimen of Cordugaster heros for which I posted a couple of photos here was taken at 11-37 on 15/06/2004 in the territory of the village of Zmeitsa at an altitude of 1260m. The location was along a stream just outside the village (about 30 minutes gentle walk to the east of the village). In the same location I also saw, but didn't photograph, Calpoteryx virgo.
Here are a four other Bulgarian dragonfly photos I have taken this year which you may be able to identify for me (although they are not very good):
The first was taken in the Rodopi in the territory of the village of Yagodina at 10-00 on 21/06/2007 at 1180m. It was on the track that leads south-south-west from Yagodina via the Chereshovo locality to the Groba saddle.
The second was taken in the Rila Planina on the wall of Hizha "Ribni Ezera" at 13-30 on 02/08/2007 at 2230m.
The third and fourth, presumably Calopteryx virgo, were from the valley of the River Arda just at the west end of Arda village (just west of the church and Samardzhiiskata Mahala by the junction to Rechani). They were taken at 11-30 on 09/08/2007 at about 1020m.
Hope this is useful. Is the e-mail address given on your website still valid? I will be happy to supply you with more data when I have the chance. I spend about half my year wandering in the Rodopi Mountains which is the mountain range where I specialize. So I would also be very interested to have any information from you about the distribution of species and records from these mountains...so I know what to look out for where, and maybe to start filling in some gaps.
Julian