I killed two sparrows with a car. I killed a falcon with a motorcycle. I killed two snakes with a motorcycle. I killed a beautiful pet cat with a motorcycle. All this over a lifetime and a couple of million miles of driving and riding. Never killed anything with a bicycle.
I remember each event with great and detailed clarity and am tearing-up slightly as I type this. Each and all of these losses were truly accidents and the result of chance, but --- I still feel responsible and sad about each and all of them.
Recently, a humming bird flew into my living room window and was killed by the impact. I picked him up and placed him where I could watch him should he recover (they often do). He didn't; he was dead. He was a beautiful creature and he is gone. Sure, there are likely a million or more of his precise kin flying around being beautiful but what, I thought as I was burying him under our apricot tree, if he were the only one and there was no other. That thought was sobering; I was reminded that each amazing example of life is precious and that I/we should never take them for granted. And, certainly, we should never needlessly, carelessly and callously destroy life. We must kill to eat; we are not plants. I believe, however, that we should carefully consider how we define needful killing.
I, long ago, taught myself to brake for and/or dodge animals if I could do so safely. "Safely" meaning without endangering myself of those around me. It is crucial that we train our minds to react thoughtfully and not revert to 'knee-jerk' actions.
Several decades ago a freshly drunk man (he was returning to work after drinking his lunch) ran across the road toward my car. I could not stop to avoid him but the oncoming lane was empty and I was able to dodge the dope. I did look first before dodging; if a car had been coming, I would have hit and probably killed him (35mph) -- my priorities were right; if someone was to get hurt it would and should have been the bozo. I had trained myself to think and react that way. I can still 'see' his face as he lightly brushed the side of my car and fell, uninjured, in a heap in the middle of the road.
A couple of decades later and late at night, a coyote ran across in front of a car very near my house. The driver knee-jerked to the right and ran straight into a large Eucalyptus tree. The impact put his young wife into a wheelchair for life. Shoulda hit the damned dog.