I think it is OK
Birds rub their beaks on walls for a reason. They are denied their natural habitat by being with us in our homes but they still have their natural needs and behaviours and one of those is to rub their beaks on walls etc to try and keep them clean and trim. What can they use if you take this option away?
Most emulsion paint on walls (plaster) is water based so shouldn't be detrimental. Plum uses the walls to give his beak a good old rub fairly often, really gets into it and gives it some.
Aluminum is largely considered the most popular non-ferrous metal in the world, and as such, aluminum alloys are commonly used in the wire mesh industry. Aluminum alloys are composed primarily of aluminum, and also contain other elements like copper, magnesium, manganese, or silicon.
Aluminum woven wire mesh is lightweight; in fact, a good rule of thumb is that, when compared to its stainless steel counterpart, aluminum mesh is approximately 1/3rd the weight of stainless. Aluminum wire mesh is also corrosion resistant in most normal environments but will corrode quickly in the presence of alkaline solutions and hydrochloric and hydrofluoric acids. With an estimated melting point of 1218°F, aluminum has many benefits, including a relatively low cost compared to other meshes. Aluminum woven wire mesh is a popular choice for a wide array of industries including aerospace and automotive, as well as marine and electrical conductivity applications.
As a large supplier of aluminum woven wire mesh, Darby specializes in stocking many of the standard or market grades of aluminum in alloy 5052 and alloy 5154. As indicated in the chart below, the 5000 series of aluminum contains magnesium which is the main secondary element. This inclusion of magnesium serves as a hardener and offers good corrosion resistance in marine atmospheres.
Alloys 1350 and 5056 are largely considered special order items in aluminum wire mesh. There are times that these aluminum alloys are on the floor or can be readily manufactured. For customers searching for specific aluminum alloys of custom mesh, please note that significant minimum order quantities may be required. Below, please find the chemical composition limits chart for the various alloys of aluminum wire mesh: