Nice to see the thermal camera in action. There was plenty of visible light in this scene so the thermal cam wasn't needed, but does it do as well in total darkness?
Admittedly I haven't had very much time with this thermal camera - so take my opinion for what it's worth... But, I think in this particular case, the thermal was magnitudes better for detection of the coyote during his surveillance phase. In fact, until it actually made its move in the optical image, it was invisible to me. It blended in perfectly with the surroundings. Once I knew where he was, I could see him, but without the thermal (or actual movement in the optical version) I would likely never have detected him.
The berm where he perched is about 100 yds from the camera location. So image clarity (during the day) was marginal at best. At night, the IR would not have been sufficient to ID the yote. But thermal provided such a dramatic contrast that it was immediately obvious that he was there.
As far as the distinction between day and night on thermal, I actually have to reference the timestamp on the video to know whether it's day or night. IOW, I cannot perceive a difference in image quality in thermal between day/night.
That said, this model is 400x300 on the thermal. I recently added the TPC-BF2221-HTM. It's only 256x192, and that is noticeably worse during the day than at night. So I think the resolution of the thermal imager plays a big part in how dramatic the daylight/high temps differ from night/cooler temps.
For example, on the BF2221 I get these:
Day:
Night
But the BF5421, I get these:
Day:
Night: