Some food for thought - especially with regards to differing diets of male and female balls pythons:

Concerning the python diet, Luiselli and Angelci (1998) demonstrated that, although rodents were the main prey type for both sexes, the males differed from the females because they fed significantly more often on arboreal prey (birds), whereas the female diet was based nearly exclusively on terrestrial rodents. The authors hypothesized that these differences were attributable to a higher use of the arboreal niche by males, as also suggested by some incidental observations of males climbed on low tree branches.


So males are more apt to climb and also have adapted to actively hunt and make use of less calorically dense prey types.

There are further studies that confirm this fact (increase arboreality of males vs. females/more varied diet) that were incidental to studies on why female and male ball pythons carry differing external parasite loads.

I would therefore argue that even if 10% were adequate for a female, male ball pythons have been studies as more active hunters that could potentially expend more calories hunting down avian prey that have less calories than mammalian prey.

A large rat is roughly 62% protein, 33% fat and has an energy rating of 6.40 kcal/gram of rat.

A chick has a similar protein profile, but 11% less fat and an energy rating of 5.80 kcal/gram.

However we can probably safely say that wild african songbirds and other ball python target prey items are more active and less fatty than a domestic chick or quail.

Bottom line - even if 10% was a safe prey mass ratio for female ball pythons, it could easily be argued that if may be too much for males.