Christmas Bird Count Tips: Owling
If you've never gone out at night to look for birds, then you need to to add that to your to-do list. Even if you don't find anything it's a great experience. Especially if this is a site you are familiar with, it's amazing how different it looks and feels. One thing I always find weird is how everything looks two-dimensional at night: you look at a line of trees and it looks like you could just step through it, during the day you can see that's it's a thick woods.
Some tips:
Try to go to areas that you are somewhat familiar with, I have hit sites cold but I don't recommend that, as I said places look and feel different at night and if you got hurt in a place that you're not familiar with it might be hard to guide people to you.
One great thing about owling on a CBC is how much night you have to work with, sunup isn't until 7:00-7:30, and sundown is about 5:00-5:30. So you don't have to be in the field at 2:00 AM (unless you want to try and hit several sites).
Pre-dawn is better then after-dark. A lot fewer people are driving and a lot fewer lights are on before 7:00 AM then after 5:30 PM, this is especially true in a more urban setting. I prefer to hit all of my good spots in the morning and just use the after dark as a back-up in case I didn't find anything before dawn.
If you have calls, use them but understand that when birds are singing, this is a territorial thing. You are not "talking" with the owl, you are challenging him for territory (as an aside, no, he won't attack you, territory control is more of a debate, who calls the longest. If you win, he might leave, and you will have lost an owl in future). Once you get a response, stop calling, let him win.
Most owls love a grove of pines, mark where those are in your scouting. If you have a large prairie near a river, try to be there around dusk or dawn to look for Short-eared Owls especially if you've seen harriers in that prairie during the day (see scouting https://www.inaturalist.org/projects/rock-cut-christmas-bird-count/journal/57237-christmas-bird-count-tips-scouting)
When doing a Christmas Bird Count, the day of the count has been planned for months and likely has been the same for years or decades, so you don't have much control over the weather or the moon, but if it is a full moon with no wind and no cloud cover then you are in the best position to get owls. However, I have also scored on windy days during snow.