this is my first post here, I am a birder who is interested in – but not very knowledgable about – mammals. I was lucky enough to spend over two months in the field in southern Colombia this year (mostly Putumayo, Narino, and Cauca departments, large parts of which are now safe after years of being out of bounds). Two mammal sightings that I figured would be of interest to the mammal watching community concerned Mountain Tapir at Puracé National Park, and Caquetà Titi Monkey in the region of Piamonte, Cauca.
The Termales de San Juan area of Puracé National Park probably offers some of the best chances to see Mountain Tapir anywhere. While you probably still need quite a bit of luck to see one, they are seen regularly enough there to have a realistic shot at one. We saw one back in January on the short trail that leads to the Termales de San Juan, but an even better spot might be the roadside pool (well signposted) about 2 km before the Termales de San Juan ranger station. Tapirs are regularly seen there, especially at dawn and dusk. The nearest large city is Popayan, about two hours away, with plenty of accomondation, but an even better option would be to base yourself in the village of Puracé, about 25 km away, where cheap and comfortable accomodation can be had at the Jardin del Condor hostal. Birding is excellent as well.
The recently described and critically endangered Caquetà Titi Monkey is easy to see around the hamlet of Miraflores (Piamonte, Cauca) at the foot of the Churumbelos mountain range, but having local guides is essential here as this is an area that had a heavy guerrilla presence until 1-2 years ago, and still has a lot of coca production. Having a local with you to vouch for you and keep you away from potential trouble spots or dangerous situations is a must. Fortunately two young local park rangers are keenly interested in birds and other wildlife and can be contacted to guide you. I can send contact info to anyone who is interested.
I don’t really have much more specific mammal info on southern Colombia – we saw a wide variety of primates that would also be found in Ecuador – but I am sure it is a fantastic destination for many more species, especially for those with a pioneering spirit!