Two comments:
I've always had tropical birds, at present 2 macaws, and have never seen them show any indication whatsoever that they feel the "hot" in peppers. Given that I'm married to a Mexican man whose favorite thing is to see how much "hot" he can stand and always keeps the freezer full of habaneros.....well, nuff said on that one!!
fancyfowl also is right on!! That same husband of mine has been cultivating a multi-generational family of crows on our property for 8 years now and that was initially started to help keep the songbirds alive long before we had chickens and swans. The crows nest way back behind the back pasture but come up to the front of the house to get fed every morning. When I'm up on time, it cracks me up to see them waiting in "their" special tree, anywhere on the average from 2-8 birds, with all eyes staring at the corner of the garage where he walks out. At the right time of year, we also have a returning pair of Canada geese and our odd-ball pair of ducks (female mallard who always shows up with the brassiest little male wood duck) These same birds have all been showing up for years......the female mallard has a very distinctive limp, one of the geese has an odd-shaped white patch on the top of the head, and it's obvious that the crows teach each new batch of little ones the feed system here. All of these birds show up just before 8am every day, and all watch the that spot on the garage where hubby walks out with food in hand. (Food for the crows, by the way, is usually old leftovers of pretty much anything we're not going to eat anymore)
We have watched the crows go after the hawks countless times, often alerted by the blue jays, and they are relentless. We have also seen them chase the bad guys in conjunction with our Great Pyrenese on the ground. It is absolutely fascinating to watch because it is so obvious that they all know exactly what they're doing.
If you've never heard of the studies done on crow intelligence (and supposedly ravens are even smarter!), then google "University of Washington crow study". Pretty amazing stuff!!