In the Winchester catalogue that is produced for the European market and found in England they advertise cartridges especially for small birds; they are called 'Super Grives' and are described as 'Light load and maximum velocity against small migratory birds'. 32 gram 12 bore in sizes 7.5,9,10,11 &12 shot.
Here is a Manufacture française d'armes et cycles de Saint-Etienne catalog from 1914
that lists a table on the right side with various animals and their recommended shot size. For alouettes (larks) they recommend #10 shot for the first and second shot when using lark mirrors. And differentiate when hunting them "au cul levé" or "with raised ass" whatever that is! When hunting that way they recommend #9 shot for the second shot. ( https://grives.net/chasse_grive_cul_leve.html
talks about this "raised ass" thrush hunting mode.)