Hi Brian, thanks for using Ask Extension,

Penetration of bark and cambium by screws or nails creates wounds that trees must compartmentalize rather than heal. Arboricultural research further indicates that nail wounds increase decay rates by approximately 30% and double susceptibility to insect infestation. While stainless steel screws reduce corrosion compared to iron fasteners, they do not eliminate mechanical injury. To make matters worse, the weight of large attachments, like five-gallon feeders (which may include snow and ice), will increase stress on the wound sites, enlarge injuries, and accelerate decay. 

There are alternatives to drilling into trees, such as freestanding poles or adjustable straps, that avoid bark and cambium injury. Straps must be monitored to prevent girdling, but they distribute weight more evenly and eliminate puncture wounds. Smaller feeders also reduce mechanical stress, as wound severity and load size directly influence decay progression. These alternatives with non-invasive mounting methods are preferable for long-term tree health.”

I hope this helps.