Compare Aromanian bardzu (“white (of horses and mules)”): both it and the Romanian word may derive from Proto-Albanian *bardza (“white”), akin to Albanian bardhë (“white”). Another theory suggests that its origin is a Vulgar Latin root *gardea, from Latin ardea (compare Spanish garza (“heron”), Portuguese garça, also French barge (“godwit”)). The confusion of g and b is somewhat unusual, but may be explained as a Balkan influence. Other cases in Romanian include limbă, rug, negură, întreba (compare also Sardinian bula, from Latin gula). A third proposal is borrowing from a Dacian *barza meaning "stork", derived from a Proto-Indo-European root *sr̥ǵos, also reflected in e.g. English stork, Ancient Greek πελαργός (pelargós). Alternatively, the Romanian word may derive from Paleo-Balkan, possibly from or via Dacian, from Proto-Indo-European *bʰórh₁ǵos (“gleaming, shining”). Aromanian and Megleno-Romanian [dz] excludes the root *barza, requiring instead *bardza. The sound change from Proto-Indo-European "sr̥" is only attested for Thracian [br] in βρία (bría, “city”) but, due to its conspicuity, it is uncertain whether it occurred as well in Dacian and with a vowel in between. These etymologies don't explain the regional variants bardăș and bardoș, that provide evidence for [d] in the term of origin and could solely be explained by another borrowing from early unattested Old Albanian *bardë or bardhë.