I guess it comes down to genetics and when is a sub species not a sub species and just a significant group with important genetic differences. The 4 sub species have / had morphological differences but I cant see any genetic studies on them. So we don’t know how significantly different they are/were. Clearly any genetic loss when the Bucardo became extinct resulted in regretable genetic loss. Bucardo was a local name for the isolated ( perhaps even significantly genetical different) Ibex population in the Pyrenees.
Interestingly I found out that skin from the last Bucardo was used to produce a clone in 2003 but this died shortly after birth due to conditional issues. Amazingly too I remember the reports of the death of the last Bucardo and if I remember correctly it was killed by being crushed by a falling branch – very unlucky! I guess too genetic material of the last Bucardo must still exist. So it is likely that we haven’t heard the last of the Bucardo.
I guess too the positive message is that one of the Spanish ibex sub species has been able to begin to re establish itself in the Pyrenees and fill the Bucardos niche and reinforce it’s ecological complexity.