On October 12, 2014, I returned from a reptile fair, and put all the unsold
Psammophis sibilans back in one terrarium. There were also two juvenile
Malpolon insignitus of about the same length and age, and I put these in
the same terrarium.
About 09.00 pm that night I noticed that one of the Malpolons was swallowing a little Psammophis, slightly longer than itself. I decided then to leave it that way, and started filming the event. After some 15 minutes I noticed that the sibilans was still alive (it moved in a turning around manner), but I expected that would not be for long. About 9.30 p.m. however, the prey was still living and moving, although it was for 3/4 swallowed. Furthermore, I considered that at second thought the prey was too large and feared for fatal results in the Malpolon. So I stopped filming and pulled the sibilans slowly and carefully out of the Malpolon. I cleaned it somewhat, and put it under the spot light.
The Psammophis had been in the Malpolon with its head for at least 30 minutes, and at least 3/4 of its body had been swallowed. It is interesting, that the venom of the Malpolon seemed to have had no effect on the Psammophis, although it maybe has been a little sedated. After having been rescued, it was put under a spot light, where it laid for about 15 minutes, breathing slowly and heavily with long intervals (some 10 seconds). After that, it disappeared among the others.
After a week, I inspected the animal and noticed many small bruises and discolorations, but it was all right.
The predator came out of it less luckily. The next day it died, probably due to internal damage, maybe caused by the turning movements of the victim.
In the past I experienced situations like this with all kinds of snakes, and John Mulder (pers. comm.) had them with Vipera kaznakovi. In almost all cases the rescue operation succeeded well. This is remarkable for three reasons. The first is, these little snakes have been without the possibility to breathe for a long period, in this case even more than 30 minutes, and still survived (reminds me of the stories about snakes that were bottled in wine, and were alive and able to bite the buyers after the bottle was opened). The second is, that the internal secretions of the predator caused only minor, superficial damage to the victim. The third is, that the venom of the Malpolon apparently had no effect on the Psammophis, apart from - maybe - some initial sedative effect. The same is the case in the little Vipers of John Mulder, but in this case both victim and predator were of the same species.
Video: Malpolon insignitus swallows Psammophis sibilans
Photo below: damaged skin after one week.