Trees suitable for outdoor structure

[Trooper]

Hello everyone: My Trooper (1 yo Eastern Gray male) is getting an outdoor structure with tunnel to his inside cage and we would like to place green foliage shrubs and trees for his comfort, fun and enjoyment. Looking at the pyramid sticky where trees and other ornamental plants are listed, I fail to see some of the options we have at hand form the various nurseries.

I remember reading a post where a more extensive list (long typed form) of trees and other plants suitable and non-recommended for tree squirrels sometime ago, but I cannot find it anymore. Does anyone know where it is?

If I am hallucinating, does anyone know where I can get this data?

Thanks,

Trooper's dad:thankyou

[CrazySquirrelLady]

I know they like oak trees of course, and magnolias, but they grow so slowly.

A fast growing evergreen tree I love to plant is the Leyland Cypress. Dunno if it would be suitable for the main tree, but they might be good for planting around the tunnel?

Hugs
CSL