Liam

It could very well be an adult female. I admit I have little experience with Western Bluebirds versus Eastern and I know Western females can be patchy.

I agree with Savannah Sparrow given the bill size and streaking on the nape

Might be my imagination, but looks like some yellow on the gape flange suggesting a juvenile bird.

Looks proportionally right for a Western Bluebird. I even see some reddish (?) feathers coming in on the breast. I'd guess a hatch year bird molting out of the spotty plumage into the adult plumage.

Nice behavioral pic too! ATTW peck at an oblique angle and strip bark by angling their head to the side just like pictured here. Often times you can find them by looking for trees that have bark peelings at the base. If the peelings are fresh enough, the tree is likely a favorite foraging tree in a pair's territory.

The band of dark streaks across the belly indicates this is a Red-tailed Hawk. The pale iris suggests a juvenile which would account for the strange plumage, though by my recollection there are some considerably pale Red-taileds out west.

Gorgeous male Violet-green Swallow

You got it. Nice catch.

Eastern Screech-Owl is a possibility. They have quite a diversity of call, but if this is one it is a call I haven't heard before. I'll go listen to more recordings (for reference, I use Macaulay Library online to listen to recordings). Ironically, someone reported a Limpkin window strike in Travis County yesterday. Not many details nor descriptive information so who knows if it was correctly identified...

Well I have now listened to enough Limpkin recordings to make my ears bleed and I haven't come across any calls that are so intermittent and low in pitch, so I'm pretty sure that can be ruled out. But now I'm deathly curious as to what this call is. I live in central TX and have never heard this noise before.

What kind of habitat was this? Sounds like there's water. Limpkin are apple snail specialists and are unlikely to show up in areas that don't have this requirement. There has been an increase of Limpkin vagrancy in the last 4-5 years (especially in the last two) due to the spread of an invasive apple snail species. I don't think this is one individual, by the way. My guess is this is some sort of contact call between two individuals (one higher pitched, one lower pitched). At one point in the recording you can hear both notes occurring simultaneously (right at 1:30). Regarding Limpkin, it should be noted they often, if not usually, show up in pairs, and vocalize at night. I'm interested to see where this goes. I may share the recording with some friends and see what they think, if that's alright with you.

Although I admit part of me wants it to be Texas's first record of Limpkin 😂

I'm not entirely sure these are birds. They may be contact calls from foxes.

Yep! Olive green back with a prominent eyering and short primary projection.

Welcome, Justin! Good insight; you've done your research and you're exactly right! I agree with Botteri's and Cassin's respectively for the reasons you stated.