One big cave and a lot of Mexican free-tailed bats

Well that was a lot hotter and more unpleasant than we all expected! At the start of June I flew to Texas for a BBC1 NHU production called Life in The air, currently Airing on sundays on BBC 1 at 5pm, to film a sequence based on the flight and navigation of Mexican free Tailed bats. I have filmed them once before for a BBC series called 'Human planet' and it really is one of those sights that everyone should see. They are one of the few bats that emerge in the summer months often before dark in their millions, which does help for filming and you can watch the shapes snaking out over the horizon for miles, it is truly amazing.

But the down side to filming these amazing creatures is that they live in caves where the inside temperature was over 40 deg C. Due to the fact that the caves contain histoplasmosis (a potentially fatal infection due to its fungus) we had to dress in full protective gear: essentially a full plastic suit, face masks, glasses, rubber gloves and boots. Highly unglamorous and sweaty as hell. It was some of the toughest working conditions I've been in for a long time.

It's hard to describe what it's like spending time in that environment. An almost overwhelmingly strong smell of ammonia hits you first as you approach the cave, the next thing that you feel is the heat as you step in, then you start to sweat. This all happens before you realise that every bat you walk under is peeing on you, there are mites falling on you all the time and then you have the flesh eating beetles to contend with. The floor in the cave had a life of its own, if some unfortunate bat fell from the ceiling small flesh eating beetles would rush towards it keen to make it their next meal. And thats all before the technical challenge of working out how to film them had begun.

It was an amazing place to be when the bats were leaving or returning to the roost, the sound of thousands of bats whistling past your ears and the occasional one crashing into your ears. I filmed much of this on and infrared converted Red Dragon, and I'm still amazed how well it coped at high frame rates in the infra red light. The bats' wings were translucent under the right lighting and looked stunning.

But for me, the highlight was filming the bats emerging at a famous cave called Frio, in Texas. It is vast. The first entrance is so big you could fit a 737 plane in there, it was perfect for our filming. There are estimated to be several million bats in that cave and the emergence is spectular.  I had an Arri Amira and a canon 30-300 for the job and they didn't let me down. From where I was filming inside the cave I could see the huge number of bats congregating in the cavernous chamber before moving out to forage for insects. It was incredible, the sound of that many wings rushing around you and the moment they decide to leave the cave, the next spectacle starts as they snake across the landscape for miles.

It was a great team to be involved with and needed all the hands we had to get the logistics, planning, Vast amounts of equipment, and the shear determination against the odds to make it a successful sequence, oh and the enormous amount of gatorade to keep us going!!! So special thanks to the amazing team : Giles Badger, Rachael Norman, Jo Stead, Nickolay Hristov,  Lou allen, Isaac Banks, and Chris.