Everyone has a different interpretation of what the rut is. I consider it the time period they display breeding behavior. From when they shed velvet (late August) to whenever breeding is done (late October in Alaska, I've honestly never seen a moose be bred) is the rut. From a hunting perspective, most would consider peak rut when they are most likely to respond to a call; from an animal behavior perspective, peak rut would be considered when the breeding actually happens. The more I go, the more I find that there's something at play that is too primordial for me to understand. Breeding behavior seems to be driven by daylight hours, temp, wind, predators, and largely by density (and obviously subspecies). From the first week of September to the first week of October, I've had weeks where one year we would call in several bulls a day and another year during the same time period you would watch bull after bull not even lift his head to look in the direction of the call. I've seen tanker bulls grouping cows and fighting off little bulls in early September and watched tanks walk right by a smaller bull defending his cows the same week without challenge. Same with end of September hunts. From my notes, typically hear our first cows around September 12th. I think cow noises that early are "leave me alone" noises and not "come and take me big boy" noises. But I'm not a moose, and they don't come with subtitles. Where I'm from in ND, season doesn't even start until the first week of October and most bulls are still rolling solo (Canadian moose). Ate several bulls shot late October and they were fine.
I'm not qualified to directly answer the original question, but those are my observations in ND and AK. It would take a substantial amount of research and earned trust before I dropped guide money on hunting anything. If it's someone you've vetted and trust giving that much money to get you on moose and keep you safe, I'd trust them on when they tell you about what to expect during the hunt. At the same time, even if I fully trusted the guy, I'd much prefer to hunt moose when they respond to calling. It's just plain fun! I used to try and strategically plan out when I was going, now I just go whenever works for mine and the pilot's schedule. Any time between the first of September to the end of the month.
The bull below was shot in AK on October 10th after a week of watching bull after bull not give two damns about calling or other cows. A snowy morning turned him on and after he was shot, another larger bull came out of the alders and started to beat up his dead carcass. His meat is as good as any other from early September.
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These young bulls were in my yard in southcentral AK on December 3rd. I grunted at them to try and get them both to look for a picture and it set the smaller bull into a frenzy. He repeatedly tried to fight the larger bull each time I grunted, and the larger bull would need to back him down. This went on for about 15 minutes. I've read that a cow will come back into heat a month later if she wasn't bred during the first cycle. It's likely that's why this young guy was ready to party.
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