[JFW67]

I’ve eight goslings at 3 1/2 weeks old. 

They are getting big for the enclosed run I have, previously used for hen chicks, and I’m wondering at what age they become safe from bird attack. 

Buzzards are our local predator in the sky.

Our chickens free range and we’ve never lost any to sky predators.

John.

[Rupert the bear]

Difficult to answer,  have  lost full size birds to buzards th thing we did was make reguges  out of a yard square boards on foot high legs that they can get under, I have seen them used a few times , but it depends how many and how quickly they get to them .
I used to bemoan covids that would steal the poultry food* and occasional egg , but they will mob and see of birds of prey.

* Now the ducks and chickens are fed under supervision  and left over goat pellets / feed used a decoy feed

[JFW67]

Thanks Rupert.

[Richmond]

They should be ok after about 5 weeks. Do you have any adult geese you can introduce them to? They will be safe within the flock once accepted.