What determines which male/female terms to use for different animal species?
- "Bull versus cow" is used for cattle, elephants, and camels
- "Boar versus sow" is used for pigs, badgers, and bears
- "Buck versus doe" is used for deer, rabbits, and kangaroos.
I can't see any logical factor that categorises any of these different species. So what determines which gender-specific terms to use for each species?
A somewhat related question, but which doesn't answer my question, is Why are there different ways of indicating gender for animals?