To start us off, I'll confess (though not for the first time) to being a wanna-be "helicopter parent" to the wild animals; that is, "swooping down" to rescue them whenever they're in trouble.
But given our current limitations in the areas of knowledge and technology, we probably can't help much more than we're already helping. As far as that goes, we could and should direct (personal and professional) research into developing better and more effective ways to help them. In the meantime, we could do little things like "saving spiders," "euthanizing a goose with a broken wing," "setting out bird-feeders," etc.
And we can help protest (and disseminate information about) the abuse of wild animals. But I'm admittedly lazy (not quite uncaring, but not caring enough either) about that.
I'm not opposed to domestication per se, and mind it even less if it's "free-to-roam" domestication (that is, an animal becoming dependent on us for food and perhaps medical attention, but otherwise free to roam as he/she pleases).
I propose a continuum for how much a (plant or) animal will be helped based on its estimated degree of sentience. Insects for instance "call for less help" than mammals; however smashing and insect for fun is immoral in my opinion.
What non-human persons we should or shouldn't eat is a tougher question. Monkeys, dolphins, seals, and whales? I'd much prefer we not view them as lunch. Other mammals? also probably not. Birds? I still don't like it. Reptiles and amphibians? a gray area but I sort of think not. Fish? Ohhh ... so many omega-3's ... getting hard to decide. Squid/octopi? maybe not considering I've heard octopi are probably more sentient than intuition would have us believe. Crabs/lobsters/spiders/insects? I don't love it but I tend to excuse myself (especially for crab alfredo). Oysters/clams? probably pretty excusable (if slightly disturbing).
Of course if one is starving and virtually no edible plants can be found, then the continuum seems to me to shift somewhat ... Most mammals might become a "gray area;" birds might become "largely free game," etc. ... but I'd probably feel like a murderous cannibal if I ate a monkey, seal, whale, or dolphin, even if I was starving.
For microbes, I generally suppose non-interference is fine, unless the microbe is hurting us in which case I feel okay about trying to wipe it out.
Smashing mosquitos is okay (IMO). But I advocate much caution about how spiders are dealt with. They generally get a bad rep that they don't deserve. Even the most poisonous ones are less dangerous than we think: Their poison isn't as potent as we think, and the likelihood that they'll bite us is much smaller than we think.
Swatting flies? excusable, I think (though I personally would only do it if they'd plum drove me past the point of madness).
I have no idea what to do about bugs infesting/killing a tree. I guess technically the bugs are probably a little more sentient than the tree, so I probably just won't interfere and I'll let nature take its course.
Where piranhas are concerned, I'd only try to save their prey if said prey was probably a lot more sentient than them, and was still savable and restorable to a reasonably good quality of life. Otherwise, I might shoot their prey if I have a gun so at least it will stop suffering (and the piranhas will still get their lunch).
Personally, when I walk down the sidewalk, I do watch for bugs and try to avoid stepping on them if reasonably possible. (Kind of hard to do when rolling a wheelchair over an "ant highway," if you get my meaning.)
While I personally wouldn't want to go on a hunting trip (let alone carry a rifle and participate), I do get that humans have evolved to be hunters just like cats and dogs/wolves have. So I don't "hate on" other humans who go hunting. I guess it's a venial sin at worst. Although, hunting monkeys, whales, seals, and dolphins is not something I'd condone.
Due to humans' hunting instincts, I wouldn't insist a human be desperate/starving before he/she went out to hunt. I would, however, insist that he/she use his/her vanquished prey mainly for its meat.
Similarly, I wish I could get myself to be a vegetarian (while not feeling obligated to be a vegan), but I know humans have evolved to be omnivores and so I consider it a venial sin for a human to eat meat (on average). Still a continuum there; I'd much rather a human ate a fish than I would he/she ate a deer. And yet, even I could be talked into eating deer meat ... elk meat even moreso ... so darn tasty ...
Personally, I dislike the idea of testing just about any animal in a laboratory, especially a mammal (and it usually is a mammal because all mammals are more closely-related to humans than birds and stuff). Instead, my vote would be to ask for human volunteers for testing on humans. Not only does that get us express consent, it even gives us a heck of a lot more precise information about how this or that drug will work on a human. I know we do have human test trials, but I mean I think we should skip the non-human testing part and go straight to the human source.
I'm okay with zoos and oceanariums (including marine mammal parks) and dolphinariums, as long as the captive animals are very well treated. "Very well treated" is wide open for private interpretation, but in broad strokes I mean feeding them well, giving them lots and lots of clean water to swim around in (or lots of ground for roaming, with comfy sleeping spots, readily-available shelter, toys and playground structures for monkeys, etc.), decent medical care, treating them with affectionate attention, plentiful opportunities for them to play and interact with one another (provided they won't torture/kill each other!), etc. ... Well garden-variety fish don't need so much affectionate attention, but a goodly amount of clean water, food, probably some fellow-fish company, and some nice hidey-holes too would be called for.
Fun side note: The zookeepers in Albuquerque have found that many animals, especially quite a range of mammals and not just monkeys, seem to enjoy handling empty boxes as if they were toys. So often it's the little creative things that help define kind and humane treatment.
Whew. With all that, I'm sure I'm already in a heap of trouble, so I won't try to think of any more questions to puzzle over right now. If you guys think of some, post 'em and I'll respond to 'em.
Kevin (the hopelessly non-wild animal).
Love means never having to say, "Put down that meat cleaver!"