Hello Janet,
I cannot help you with your specific query, but I do have various bits of info.
I found a Bird family in the 1851 census for East Grinstead, listed as Vagrants living in a tent in Ashurstwood. The only place of birth given, was for the head, Moses (30) and that was Limpsfield, Surrey. His wife is Ellen (28) and his daughter is Sarah Ann (1).
There are also three families in the 1881 census, two are Pedlars, living on Mitcham Common, the third, which may prove interesting is:
RG11: Piece/folio 0827/65: page 8
Dwelling: Half Acre Row, Mitcham, Surrey
Thomas Bird, head, married, 60, born Godstone Surrey, Hawker
Susanna Bird, wife, married, 59, born Speldhurst Kent
Generally, going by the places of birth, where they have been given, they seem to travel across Kent, Sussex and Surrey.
If you want any more of the census info in more detail, let me know.
Phil