We followed Arena north to her site on the Ungava Peninsula last summer. By monitoring her locations, we realized over time that she likely did not breed this year. Her signals ranged too widely to indicate that she was incubating in a single location. Lindas signals, in contrast, "drilled a hole" in the map.
As the season wore on, we noticed that Arena started to head west, again indicating that she did not breed successfully.
On 9 July, we received an anomalous signal from her transmitter. We realized later that this was probably the beginning of a malfunction in the unit. It showed that she was not moving (0 speed) but that she was over a large lake. Since there were no rocks or islands visible on the map, we questioned how she could not be moving and yet be over water. We considered that she was in the lake itself, i.e. had suffered mortality, but the temperature of the transmitter was too high to be immersed in the chilly arctic water.
On 13 July, we received several more signals showing her position further down the lake, this time somewhat near the shoreline. Then the signals stopped altogether.
The transmitters have a built-in mortality sensor (GroundTrac) that sends a signal automatically if there is no movement over a two day period. However, no such signal was generated by her transmitter. So we have a mystery regarding the whereabouts of Arena. We made an unsuccessful attempt to visit her last known location in Ungava but the botanist working in the area was prevented from getting there by poor weather and limited helicopter time.
Our best opinion, based on extensive review of the data, is that her transmitter failed. This happens a fair amount in the satellite transmitter field. In fact, we are quite lucky so far that no more have failed. During a recent study in Europe on Saker Falcons for example, three of ten units failed.
The team plans to go visit Arenas territory in Chile this October in hopes of seeing her there and clarifying what might have happened.
