Hi guys! We have had Pumpkin 3 weeks now (she is knocking on 8 months old now) and the other day when we came back from errands (she was crated), and we let her out, she greeted each one of us, individually with a hearty BAROOOOO and we notice the base of her tail was wiggling for each of us. We had fostered a non-puppy male some years ago and NEVER saw his tail move in the three years we had him. We are curious what your B does. It is hard for me to tell if she is happy, so this helps a lot. Also, what does your B do to tell you he/she is happy? Thanks for all your help! 
Our Africa-born girl wags her tail. But like you say, it's more subtle than with other breeds, since the tail is so curled. But I'd take barooing and wagging as a good sign! 
Cosette also jumps up (we have to ignore her) and tries to lick our faces (which my wife allows, but I try to avoid...)
Fabulous! All of mine do tail wags and some sort of greeting-makes me love them more!
I get Woo HOO from one and the ruff goes up on the other. One would lay down and show his belly with the tail wagging. I find the more of a big deal you make the more they do it.
Definitely! You can really get an excited basenji riled up by playing into it. We try to ignore it, since we don't want to encourage Cosette to jump up on people, but it's hard not to acknowledge the behavior! Another thing she does is she shakes when she's excited or overjoyed, like she's wet, but she has no water on her.
Thanks as usual! You all have been a blessing for me!
I raised two litter mates together and they waggled their tails on command. Every time they wagged their tails I made a big deal about it and eventually they learned the word!
Basenjis are often stingy with their tail wags. Some of mine seldom wagged, but if something particularly pleased them they would. Watching a prey animal that was close to the window, e.g. chipmunk, would evoke a wag. Anticipation?
Yes, rewarding a behaviour will increase the chances of seeing it again, but one has to be a little careful. If you make too much of a fuss over a dog when you return, it can feed separation anxiety if your dog has any tendencies to that behaviour. I was happy when my dog didn't really acknowledge me after a short absence. I must admit, I liked to be greeted if I had been gone for a week, but that didn't always happen with all of mine! Getting an "oh, you're back" low key reaction was something I strived for with my last two boys, since both had separation issues and keeping things very matter of fact kept that problem at bay.
All 3 of mine waggle their tails when happy. But baroo envy. Arwen and Cara lack baroo ability. 
Our sisters Lela and Binti do not wag their tails at all.
Elliot, my red dog, wags his tail every day. It's not a very fast wag and only does it when he's really happy. It's adorable! My first red did the same thing. The tiniest wag of happiness! Cody also "barooed" all the time.
My brindle dog Morgan only wags his tail when he's SUPER excited. When he meets people on walks or sees his breeder at a dog show. His tail helicopters when he sees his breeder!
Mine have a subtle tail wag but their butts are wiggling so much its hard to tell
