Not sure allikat, he was involved in a nasty territorial fight that summer duriing which he was badly wounded and unable to hunt for awhile. His mate actually stepped in and drove off the other male, otherwise he probably would not have made it. She then fed both Pete and their young until he was back on his feet so to speak. Watchers could see he was flying lower than normal but was expected after that chest wound - you could see it in the photos at the time but he seemed to recover. When he was found months later - no one knew why, did he fight again? Or did he fly into something? I did read up a bit last night and it is possible that a cranial blow will cause a lesion inside their brain which can cause seizures. I will keep reading to find out more, it was quite interesting.