Thanks to this world map that shows the density of people with the surname Cayro in different countries, you can get an idea not only of the popularity of the surname Cayro in each country but also of the different migrations of people surnamed Cayro.
The quantity of people with the surname Cayro that we can find in each country can help us discern the origin of the surname Cayro, as logic tells us that the place with the most people surnamed Cayro will be the country or area of origin of the surname Cayro.