If a female nursing pups is killed will another female nurse her pups or are they sol?

Don't know for sure, but I would say one of the females kept around the family group would serve as a "Nanny", but not for nursing. If the mother coyote is killed when the pups are dependent on milk alone, I doubt they'd have much chance. If they have already started being fed regurgitated food, that is within their capabilities.

About what time of year would they be done nursing?

Not so much a time of year as much as it relates to when they are born. Once they start eating regurgitated food, mama starts to wean them within a few weaks and gets them started eating grasshoppers and other insects. Around here in Ky., that will usually happen by the middle of May to first week in June. If mama gets killed after that, the nannies can take care of them well.

Interesting question. I've watched many hundreds of pairs of coyotes in the wild. Only 1x have I ever witnessed an omega with the alpha pair. I figured it was an omega yearling. Because it acted submissive to the other two coyotes. Which were both slightly larger. That occurred late in the breeding season.

Was that omega a female? I suspect so. But can't prove it. I believe that omega female was not dispersed. So the alpha male had another female to breed. Not for the intention of having a nanny. Specifically, a nanny used for nursing the alpha female's litter.

I read many years ago. One coyote hunter claimed when a family of coyotes make a large kill. They will howl to call in non-related coyotes for the feast. Again, I do not believe that opinion. Like wolves, coyotes are family oriented canines & are not receptive to "trespassers" on their marked territory. Especially when it comes to sharing their kills.

^^^^ totally agree. Coyotes are very very territorial and if the mother hasn't weaned its pups completely, the pups have little to no chance of making it and will certainly die a very long and painful death from dehydration or starvation. This is EXACTLY why I quit in March in case pups are born early and leave them alone until October.

That gives them every opportunity to be successful adults to hunt later on and IMO killing adult coyotes knowing there are needy pups is pretty dang cruel. Unless they are legitimate problem coyotes I leave them be.

It is interesting to me. How we base our opinions on what is true. I average out things I have witnessed. As I try to seek the truth or reality of the matter. It would be ignorant to believe I've seen it all. Not even close, is the reality of that. Not being a coyote, fox or wolf. We can be right, come close, way off base. Or otherwise theorize in our own experiences. I also happen to believe even Biologists sometimes are a skew in their summations. Because reality is, they have not seen it all either. Reminds of me people claiming to know what a coyote vocal actually means. Even the most Worldly of them. May come close to the truth. But again that is theory. Getting back on target. I'm pretty sure. Coyotes are not into welfare. haha

Speaking of territorial. In my experiences from what I can recall now days(I had a stroke many years ago. Which left my memory not in the best shape. But fragmented to say the least). When a trespasser is on another coyote's land. That trespasser is most wary. Constantly looking around. One trespasser coyote I watched which was bedded down on a hillside. Never lowered it's head as it was curled up. That coyote kept looking 360. I thought he/she is looking for the territorial pair. That coyote never fully relaxed.

Another hunt. I seen one bedded down on a hillside way out there. That coyote was also constantly looking 360. I looked off to the right & seen a pair of coyotes. Stop maybe 1/4 mile from the trespasser. Now they all see each other. The trespasser sat up for a better view. Then took off in the opposite direction. Like it was shot at. I agree they are very territorial. To non-related coyotes or other canines. I've talked to a number of farmers over the years. Who have told me of coyotes fighting their farm dogs. Some fights even occurred in the farm yard. One story I was told by a farmer. Two coyotes tried to kill their dog. As it was chained near the back door of the house.