Curious observation

I´ve noticed in Peru that the water in toilets does not swirl as it goes down in the bowl. I´ve been told that in the Southern hemisphere, water swirls the opposite direction from in the Northern hemisphere. But the lack of swirl confuses me a bit.

We are not right on the equator, but at about 15 degrees South latitude. My only guess is we are close enough to the equator that the swirl is minimized. I will continue collecting data in toilets around the country. Stay tuned.