Brazilian horse and dog commercial porn begs the difference. Plenty of dark skinned ladies there.
This right here.
This right here sheds some light on why this myth, and a myth is what it is, exists. This whole idea that black people in general are not into zoo is PURE myth. Are there fewer in areas like the US? Yes, because black people are literally like 12% of the population, so, by definition there would be fewer. But, I have been to several countries in South America and you know what's rare there? Whitey. Most everyone in these countries are from light brown to dark black. That entire spectrum of the rainbow, but white people are so rare it's NOTEWORTHY when you do see one. No idea what the zoo numbers there would be, but the porn coming from there points you toward the answer.
I can't speak for the rest of the world, because I live in the US, but here, I can say a few things. First and foremost, this myth exists because what most are seeing is a cultural mirage. Yes, black people and white people do mix, but it's not as mixed as you would think, and in some places, hardly at all. More to the point, white folks have white friends, and black folks have black friends. Yes, there is some cross-pollination, but again, not as much as you would think and not very much at all in a lot of areas in the US.
Without getting into all the racial stupidity that exists, I'll just say again, that there are plenty of black folks, male and female, who are into zoo things. The reason it seems less or almost non-existent to most people is because you aren't hanging out with black people or where black people are, so the perception is a little skewed. Hell, for a lot of people, based of the circle of people you actually know, there might not be any black people. Which we ALL know is false.