Which Cranes Get PTTs?
Sara Zimorski, ICF
the Beginning. . .
first (2001) we put PTTs on the largest males and largest females
since these birds would have to wear/carry two transmitters: a radio
transmitter on one leg and the PTT on the other.
Platform Transmitter Terminal (PTT) is
a satellite tracking device that can be worn by an animal
so its location is known. (This is on a plastic
crane leg model.) Photo
VHF radio transmitter is on the left leg and the PTT satellite
transmitter is on the right leg.
Photo Sara Zimorski, ICF
#208 has a PTT on the right leg and
radio transmitter on the left leg (red/white).
Sara Zimorski, ICF
By the time we were raising the 2003 birds, the tracking and monitoring
data clearly showed two things:
therefore decided to put PTTs only on females. A PTT was
almost wasted on a male that came right back to and settled down at
However, a PTT might be very useful on a female that wandered
into another state.
Again, because the bird would be carrying two transmitters,
we chose to put them on the largest females. In 2003 we didn't
to choose from; we certainly weren't going to
put one on #303,
had a leg injury and surgery to correct it.
In 2004 we had 4 females but only 3 PTTs available, so the youngest
and smallest bird (#420) wasn't going to get one. Unfortunately
#406, one of the few females, died. We were left with only 3 females,
each of them received a PTT during the banding and health check
that took place after their arrival at Chassahowitzka. As for male
he was the first supplemental release (Direct Autumn Release,
or DAR) bird in the Eastern flock. We didn't know what he would do
as he migrated
on his own, so we decided to be extra cautious and put a PTT
on him. That way we would always know where he was—in case he
ever got away from us during the regular tracking. Because he was
in this new type of release it was very important to document
where he went, when, and how. The information would help to justify
doing more releases of this type, or reveal the need for re-thinking
the release strategy and method. Luckily #418 did super, and the
Direct Autumn Release (DAR) experiment began in 2005.