Problem:
According to the BBC documentary "Wild about Pandas", about half of panda birth results in twins.
Question: Why do they have such a high probability compared to other mammals?
Question: What factor(s) control that fraction in general for mammals?
Additional question about the algometry formula:
I am a little surprised that it is not the ratio between the neonatal mass and the adult body mass that enter the formula, but just the neonatal mass.
Please give your ideas on the above statement and answer the questions mentioned above.