I live in Rock Hill, SC. Not affiliated with a club but I Bought a better camera and learned how to use it because I took a trip to Australia in 2018. I still have many ways to improve.

Excellent pictures. My set up was almost the same as yours; Canon T6 with a Sigma 600 mm lens, glass filter, and then iso 200 and 400, f9,and 1/100 sec shutter speed. The only thing I think I did wrong was not varying the shutter speed to compensate for the total light reception. My pictures were almost the same as yours but slightly more exposure. I was in Greencastle, IN although I had intended to go to Texas just like you did.

I just returned from Australia (all of April). I went to Melbourne area for a an outback trip. I took pictures of many critters that are not in the zoo. Then went to Sydney for a few days before a Princess cruise up the east coast.

I have several hundred pics from the trip, but I still didn't shoot everything.

Here is a picture of a family of Tawny Frogmouths on Roydin Island, Victoria, Australia.