Don McCall writes the following....
"Felipe's battery has weakened to the point where we aren't currently receiving either GPS or Doppler location data from his backpack transmitter."
This indicates that the transmitter is not getting enough sunlight to charge its solar cells. Usually, that means that it is lying upside down somewhere.
There are only two reasons that I can think of for that to happen. Either Felipe has removed his transmitter and it is laying on the ground. Or he is no longer living.
We have had both scenarios occur during this project in the past. It is possible for a falcon to remove its transmitter. Another Putu adult male peregreine, Fireball, did so several years ago. It was recovered over a year later on an island in Hudson Bay.
We all hope that is the case.
However, the only way to confirm what has happened is to send someone to the last solid GPS location and look for the transmitter.
We have good coordinates and we have an excellent contact in Cuzco that knows how to look for the location. Our Peruvian guide, Luis, has agreed to search for the unit if we can get him a handheld GPS unit. Fortunately, we trained him how to search for GPS coordinates on our recent trip through Peru.
Unfortunately, this will take time as he and Shirley are still trying to ship our vehicles home from Guayaquil. New regulations have made it almost impossible to ship trucks in containers now.