Resembling ‘squashed kiwifruit’, wet bats aren’t the prettiest creatures, so the photography team trialled some hair-raising tactics to get realistic shots of these rare, endangered creatures.
In a storeroom stands a row of glass jars with short and long tailed bats housed in 75% ethanol baths that allow researchers and the public to view these specimens and representative holotypes.
For decades these specimens have been soaking in the ethanol to preserve their form and condition however once out of their bath they resemble a ‘furry wet mess’. Recently, the collections and photography team were challenged to present these lank creatures in a more identifiable and life-like state.
As holotypes and paratypes, these specimens are extremely valuable and completely irreplaceable, as they are the exact individuals that the two species were described from. So staff needed to adhere to strict practices to ensure they stay in immaculate form.
The photography had to take place in a swift, military style operation. Drying them out was not an option.
“It is like a grape, if you dry it out and then rehydrate it, it will never return to being a grape, it would just be a weird wet raisin. It has to keep its structural integrity,” says Collection Technician, Nina Gaze.
After a disappointing Google search seeking insights from other institutions, the team decided they had to come up with their own solution. Enter ‘stunt bat’ – a non-type bat was used to test and explore the most appropriate way to photograph the bats.
The trial and error phase resulted in the decision to photograph them in a water-bath to suspend the bat’s fur as if it was dry. One of the problems with photographing specimens preserved in alcohol is that there is a small risk of combustion. When the alcohol evaporates under the photography lights, there is potential for explosion when the flashes go off which may result in singed bats– not ideal!
To avoid this outcome, they had to be eased into sobriety. First they were titrated into 50% alcohol for five minutes, then 25% for five minutes, and finally into pure water. During this step-wise dilution process, a cloudy plume rises from the bat. This is a phenomenon called the Ouzo effect.
This happens because the alcohol emulsifies the oils from the bat and allows them to mix evenly throughout the water, giving that cloudy appearance (the same effect as adding water to Ouzo). Eventually, the oily clouds dissipated, so the first obstacle was now overcome.
Upon closer inspection, however, it was discovered that the bats were now dotted with tiny air-bubbles.
Initially the team tried to remove each individual bubble with a paintbrush, though this was time consuming and potentially damaging to the fur. So other methods were developed. The water tank for photography was settled overnight, so that free oxygen could disperse, and some strict bat-transfer protocols were adopted.
Using a slotted spoon and very steady hands, bats always had to go into and out of the tank head first to keep the fur in the right direction to minimise bubbles.
The final challenge, was that once in the water tank the bats floated up to the top. So the team developed a sort of seatbelt from clear nylon fishing wire that delicately helped to anchor them to the tank’s bottom in a precise position.
Battling sweat and nerves, the team then took on the task of photographing the thirteen bat specimens by employing the utmost skill. Now that the exact method had been established, each bat took around one hour to shoot, including the distillation period.
Innovatively, through expert photography planning and a bit of Kiwi ingenuity, the 9 litres of water in the tank acted as a volumetric light pipe that enveloped the bats in a perfect light cloud. All the photographer needed to do was place an uplight underneath the tank with two soft boxes on either side and shoot from above to avoid refraction.
And voila! The final shots produced at the end of the two-day shoot showed the careful line the team had to walk to maintain the condition of these precious specimens and produce clear, identifiable photos for scientific purposes and public viewing.
“We could have removed every single bubble but because we didn’t want to disturb these precious specimens and we had to return them to their alcohol baths, it was important to find the right compromise,” says Collections Photographer, Richard Ng.
The pictures of these holotype specimens can be found on Collections Online.