Bird house/hollow advice pls
Hello all! After a bit of advice:
Background
I am lucky enough to live in a leafy suburb of Brisbane, on a private estate with plenty of unbuilt common property. Unfortunately, a lot of this is overgrown with invasive plants, but I do my best to keep it away from my property and have added a tonne of native plants to my backyard. Now I frequently get natives eating the flowers and visiting.
Through my own eyes and my birdnet-go installation, the area gets torresian crows, pied butcher birds, noisy firebirds, pied currawongs, magpies, sulphur-crested cockatoos, tonnes of striated pardalotes, kookaburras, brown honeyeaters, Willie wagtails. The smaller species entering my backyard to drink or eat the flowers.
The question
I have a 4m-high sandstone retaining wall along the back of a 15m native garden. On top of that retaining wall I’m growing a hedge of Lilly pilly too.
Is there any sort of bird house or hollow that’s cheap/affordable/DIY that would suit hanging off the top of this stepped wall and be suitable for the honeyeaters, wagtails, etc?