The normal mist nets we use for trapping bats are 2.6m high. These nets are very effective however many bats fly higher than 2.6m. A way to trap higher flying bats is to use a high net.
The high net uses a pulley system to stack three mist nets on top of each other, giving us 7.8m of net to play with. When a bat is caught at the top you can lower the net to ground level to extract it. The one we use is home-made, we have designed it to be ultra-lightweight – it’s supported by two 8m carbon fibre poles.
We were using the high net recently in Bladen Nature Reserve, on the entrance road to BFREE. We found a spot with low canopy where the net completely blocks the road. We were hoping to catch some interesting things, however it was raining and we weren’t catching much. We were just about to give up when a huge bat (below) and a headless bird (right) landed in the net. The bat was a Woolly False Vampire, Chrotopterus auritus, a large carnivorous bat found from southern Brazil to Mexico, it’s unlucky travelling companion was it’s dinner.
C. auritus is a gleaner, meaning it hunts by flying quietly and listening for noise made by it’s prey. Once it’s heard something, like a snoozing bird, it then hones in, grabs it’s prey and kills it with a bite to the head. It then takes it back to a perch to eat, however males have also been seen to bring food for their mate (R. Medellin, personal correspondence).
We don’t know whether this little yellow bird was meant to be devoured or shared, either way it wasn’t taken – the bat dropped it and flew off empty handed.