Arjan I envy you the opportunity to see and photograph these giants. Was there a particular reason that you cropped it in semi-panoramic fashion?
I might have been tempted to make a panoramic of the two playing in front and using F6.3 to try and make the other elephants more OOF but I'm not sure that the OOF part would have worked with the distance that you were likely photographing from.
The crop seems to work for me. You've filled out the image with elephants though the elephant on the right with it's eyes so close to the edge of the frame is a bit bothersome. Your center of interest is defined by the interaction but I also think that by capturing this image with the lens wide open the BG elements would be softer a compete less.. Not sure frorm the image as posted here if you managed a catchlight in the elephants eyes.. That can be difficult. Very nice overall.
Arjen, good to see you here. An interesting photograph for sure. There is a lot going on in this photograph. I agree with the comments that Robert made. It migh have worked better with less space on the left, and more on the right... I'm looking forward seeing more photographs from your SA-trip.