You mention drones. If you are going that route you might have something in common with what the sloth people are doing.

Read "First record of sloths using thermal drones - SloCo" on The Sloth Conservation Foundation

First record of sloths using thermal drones - SloCo

Drones are revolutionizing the way scientists collect data, especially in the study of biodiversity and conservation.

The Sloth Conservation Foundation

I don't have experience with OU, but currently doing a GPS/VHF tracks on crocs in Jambi.

Both GPS and VHF have their plus and minus.  But with the homerange up to 2500ha, I guess GPS is better? For the GPS also it can be as light as 30gr like this ATS with solar cell . There is also a novel development of kinetic harvesting system too, but not sure if it's already accessible.

Aside for choosing the right tech fitting with the resource and purpose, I think one of the important thing for this OU is choosing the 'attachment' since they are super smart and anything could get wrong, from hurting themselves trying to figure out the microchip implant or social issue when they have peculiar stuff on their body? please CMIIW.

GPS collar is the common one for mammal and primates, but for OU I think it is too appealing. I bet we can order custom small GPS collar but as wrist band or hand watch, and train/habituated the OU to ignore that. And make some camouflage with the color and fur?

Hi @alina29 

I'd echo @hjayanto's point about how the orangutans cope with various animal-borne approaches - I guess implants are seen as the most practical as they aren't as likely to be removed (although I imagine even implants can have problems)...As @hjayanto suggested, do you think it's possible to habituate orangutans to certain devices? And will released orangutans be regularly monitored (e.g. by people on the ground) and likely to stay in roughly the same area (e.g. where monitoring stations or drones with receievers could be deployed), or are they likely to move large, unpredictable distances? If they are likely to move long distances, then GPS devices that can upload data to satellites would likely be the best option (provided orangutans are ok with the devices). The Horizon tag from Arribada Initiative is one possiblity and the collar from Margo Supplies is another. If they are more likely to hang around in the same areas, then other tags such as one @BionicHold is working on (link here) could be worth considering. We also have some small, BLE tags that can be detected by a phone app., but the range is limited in dense bush (better from drones). 

Cheers,

Rob

Hi

We are currently doing Baboon tracking, but in a closed area.

There is some new Tech available soon that we can go direct to Satellite, but we can only do a couple of updates per day, powered from a primary cell.

Let me know if you are interested

Regards
Sam