TL:DR – There are lots of regional slang names for the House Sparrow.
Do you have a local word for Passer domesticus, the House Sparrow? Where I grew up in the North East of England we called them Spuggies, I hear from a Shropshire lad that it’s a common nickname for this species in that part of the country too. They’re also sometimes simply called spugs in Northern England. In the South P. domesticus is known as a sparr, sparrer (or Cockney sparrar), spadger (Northern Ireland too), spadgick, and phip or philip. That latter one is intriguing.
In Scotland, they’re often known as a spur or sprig (also Spriggies after a Mr Sprigg, apparently, that sounds unlikely given spriggies sounds like a dialact variation on spuggies). One contact on twitter (hahah!) said that his father who grew up in North Lanarkshire called them speugs, pronounced “spee-ugs”.
It’s very difficult to discern the etymology of these nicknames some sources cite spadger as originating in Leeds in the North rather than the South of England. But just as nicknames for games and people often arise with -er on the end. Bradders, was an occasional nickname for me as a bairn (child). Soccer is short for association football as Rugger is short for Rugby Football. Sparrow perhaps became sparrah, spugger, spuggie…
The same species is often called an English Sparrow in North America where its nicknames are commonly spatzie or spotsie, from the German Spatz. Australians might know the immigrant species as a Spag or Spoggie. And, perhaps less common Sprog or Sproggy and even spridgy or spudgy.
There are others: spyng, spurdie (from The Orkneys), chummy, craff, hoosie, row-dow, thatch sparrow, tile sparrow, and eave sparrow. (Cited here).
In Dutch, the species is known as a mus, or more specifically huismus, but that’s the official common name not a nickname. Spatz in German.
Reader Steve E emailed to tell us that in East London sparrows are often known as squidgers.