'Ethic' is a powerful word. It feels like something that is carved in stone when someone states it as part of their belief system, or as a reason they chose to stand for or against something. By definition, it is a set of moral principles. These principles guide an individuals conduct.
Moral is a person's standards of behavior or beliefs, something that outlines what is acceptable or unacceptable.
Principle, as the next thing to define, is a fundamental truth or proposition that serves as the foundation for a system of belief or behavior or for a chain of reasoning.
So we have a fundamental, foundational, truth (or set of truths) that is the basis for a person's behavior. Big stuff, to me.
There are very few things that are that foundational in a person's life, few things that cannot be challenged. Most things are contextual. I could state that I am against killing another person as an ethical position and it might seem like a good, foundational principle. In the right context though, I am ready and willing to harm someone, even kill them, if they threaten the life of my loved ones.
When we then begin to talk about a land ethic, via Aldo Leopold, or a hunting ethic, via Orion- The Hunter's Institute, this can get pretty murky pretty quickly. Topics like ground swatting a grouse or shooting a flying turkey, once we get beyond safety concerns, seem less like ethics and more like personal preferences that can and should evolve over time. If I haven't shot a grouse this fall and want to eat one, I might shoot it safely on the ground as opposed to a situation where I've got two grouse at home ready to cook and I decide to challenge myself by only taking one on the wing. The shooting of grouse doesn't occupy the ethical space, it is merely the place to bounce a deeper principle around. The principle might be to provide food, personally challenge oneself, not take too much... highly variable, based on the situation of the day, the week, the month.
So we're left with situational ethics- ethics that apply in a narrow band of a person's life. These are fine, and good ground to test things out, but I find that these are mostly mental gymnastics. Throw one more "what if?" in there and the whole thing changes.
Thus the ethics of a situation are grounded in the fundamental, foundational, truths of a life. These can, and should, be tested and modified, shaved down to the barest statement, burned to the roots, as time passes. The rest ends up as window dressing that keeps philosophers employed.
Figure out your foundation and follow that. You'll know when you've strayed, if you're honest with yourself. Any complication that arises shows us that we haven't taken laid it out there far enough. Every person has his/her own set of ethics. Conversations may sway us, make us reconsider, but the truth will remain.