Stacia sent me a link to this and it is just too adorable not to share.
This hummingbird was being measured for how much oxygen it uses and the video captured what sounds like hummingbird-sized snoring.
Watch the video (might have to refresh this page) and read the full writeup from It’s Okay to Be Smart
Interesting comment on this from hummingbird expert Sheri L. Williamson (from the site linked to above):
“I’ve handled thousands of hummingbirds, and this appears to me to be a bird awake enough to be aware of the researcher(s) but still too deep in torpor to defend itself, and the “snore” is a distress call. It’s an admittedly small sample, but the single hummingbird that I’ve observed while it was emerging from torpor didn’t make any sound at all (but it also didn’t have a bright light shining in its eyes).”
I’m guessing this sound would pique the interest of our dog, Bella.