In Croatia, Birta families are generally Croats (from Velika Gorica ), very rarely Serbs, and . In the past century, relatively most of Croatian residents bearing this family name were born in Virovitica.
Prevalence
About 30 people with faimily name Birta live in Croatia today, in 17 households. There were 0 of them in the middle of the past century, and their number multiplied. They are located in 7 Croatian counties, in 6 cities and 7 other places, mostly in Zagreb (15), Velika Gorica (<10), Djurdjevac (<5), Karlovac (<5), and in Sesvete (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1906 in source Yearbook and Directory of Literary Society of St. Jerome 1906.