I’m guessing you’re in America? The American goldfinch and the european goldfinch bear little resemblance to each other, and as far as I am aware, are totally unrelated. I guess we just use the same word for different birds.

I know it’s off topic, but you asked a couple of questions over at my place, so I thought I’d come over and say hello and put the answer for you here as well. Thanks for reading such a long article and still wanting to ask questions

Hollow tining is a way of lawn aeration (and counteracting the effects of compaction) that’s more effective than using a fork. You use something that looks similar to a fork, but each tine looks like a tube. You then spike the lawn and little cores of lawn and soil come out leaving small holes around 4 inches in depth. These holes should then be filled so that aeration continues.

The usual filler is sand, but the council are using recycled rubber instead. Now I’m not sure about this because over time there must be a chance that the hollow tining brings up rubber instead of soil. And it doesn’t rot down either. I was wondering whether fine grit might be the solution instead if the usual sand isn’t good for London’s grass. I’ll see if I can find a link for hollow tining and insert it into my post just in case others have the same question.