You would think this, wouldn't you? Because that's how zero works in our number system.

In reality, there was no year 0. It just skips straight from 1BC to 1AD.

There was a very interesting interview with someone on the radio a few months ago (Radio 4, UK) who had written a book about primates.

He said that idea of a dog having a gender (i.e. distinct from its sex) was ridiculous. But he told us about his observations of chimps that were born female yet followed all the typical male-chimp behaviours, joined in male friendship groups, etc. It really sounded like a female chimp that identified as male, from what he said.

Difficult to really know what was going on since - as you say - they can't communicate with us.