I had fin today this male Thomson's gazelle in Serengeti Park in my search in zooniverse snapshot serengeti app
Is very easy differentiate male from female by the horns (both have, but the male's horn are more heavys).
It's also esay distingish Thomson gazelle from others (as Grant's gazelle) thanks to the dark line over the abdomen.
[Zooniverse snapshot] is a program where the volunteers identify images taken by automatic cameras hidden in natural enclosures.
You can also try make your own virtual safari registering in zooniverse and creating your own album in steepshot
Regards.
Will see you in the savanna.
** ;-)**
From @freyman