It’s also not clear that they are getting better at breeding pandas. So long as the number of pandas born in captivity exceeds deaths, you would expect the numbers of births per year to keep growing. Start off with 2 rabbits and let them breed to their hearts content, and you’ll be getting record-setting numbers of rabbit births every year, too. Surely some sort of fecundity ratio for pandas of breeding age would be a more appropriate metric. Of course you would then want to see if changes in the reproduction rate are statistically significant before concluding that improved fecundity is correlated (let alone caused) by scientific advances.
