Preparing for a significant birthday recently, I was on the hunt for photos of me as a baby. I realised fairly quickly that I didn’t have very many. Certainly fewer photos that I would now take on a single, normal, weekend day if I was with my family.
That’s not too surprising. Back then you had to take a photo and hope that everyone had their eyes open, or that you had the focus right, or the correct exposure (or that you had actually put the film into the camera correctly and it was actually taking photos). At some point you would drop your film canister to a chemists to send away to be developed into photos. Then you often waited weeks for them to return. Pulling the photos from a pack was always done with great anticipation. Had I got the shot? You couldn’t waste your shots, so taking photos was a special event.
I reflected on this recently at the funeral of a friend’s mother. As is commonly done, there was a powerpoint of her life in photos. Unusually, there were lots of photos of her as a child through to her 20s. Great black and whites, taken by someone who new their stuff. The photos showed a nice young lady, well presented and neat. She obviously enjoyed the company of her sisters. And at some point a nice looking young man started to appear frequently.
But it was the other details that I liked. She had grown up in 1940s and 50s England and there were all sorts of interesting buildings and signs and public spaces in the background. Everything looked like an episode from ‘Call the Midwife‘. It was a great reminder about how much the world has changed over the last 60 years or so.
How things have changed. It was estimated that 1.2 trillion photos were taken in 2017. Most are selfies on smart phones. A good chunk are of cats and other pets. It’s fair to say that up until the late 1990s that there were very few selfies (they were hard to take and why would you waste your precious camera roll?) and far fewer of cats (but probably still a reasonable proportion!).
All this image taking is not necessarily a bad thing. In ecology, photos have become a useful tool in all sorts of ways. They can be used to show before and after in areas that have had major impacts. The can be used to census colonies or forests. They can be used to measure productivity in areas. They can be used to monitor populations.
Cameras have been a great addition to be able to detect and count populations. Monitoring is usually difficult. How can you count individuals when they are cryptic, actively hide from humans, perhaps that are only active in the dark? For pest mammals we have had traps, but that impacts on the population that you are counting. We also have devices that can be interfered with (usually bitten) that leave clues as to what was there (wax tags and chew cards for example). The problem with these as you don’t always know exactly who bit the devices or when it happened. And now we have cameras.
Cameras are active all of the time, ready to take photos day and night. You can record when it happened. You can record the individual that was captured (and perhaps confirm that the same individual was in different places and recorded by different cameras). You can even set it up to record video if that is useful. For the most part, most species do not notice the cameras, or at least they don’t change their behaviour much if the see one.
In wildlife pest management we are very interested in finding our pest species and estimating how many there are. This can tell us when it is time to do some control to reduce numbers. It can tell us how well we have done with our control. It can show us the spread of a particular species. Trail cameras have become a very useful tool for helping us to do all of these things. Trail cameras can be set up in the field and left to take photos as animals walk past the camera and activate it. Over the last year at Lincoln University we have used cameras to monitor cats, stoats, rats, possums, black-fronted terns, kiwi, red panda, and Pakistani leopards.
If ever a species was primed to do well with trail cameras it would be cats. After ourselves, cats are the species that have the most photos taken of them. The trail camera goes one step further by allowing cats to take selfies of themselves. The internet may break!
Cara Hansen, with Adrian Paterson, James Ross and Shaun Ogilvie, were interested in cats across the New Zealand landscape. There have been studies of cat densities in urban area where there are lots of pets (e.g. 1.3 per household in Dunedin). There have been a few studies of wild cats in remote area. Cara was keen to see what happens in wild areas on the fringes of urban areas.
She set up a network of cameras in Orton Bradley Park on the shore of Lyttelton Harbour. Orton Bradley is a protected area with a suburb on one periphery. Cara talked with local cat owners and built up a library of 40 domestic cats that live in the local suburb. She then left the cameras on over several months for the cats in Orton Bradley to take some selfies.
Cara reports in a paper published in the New Zealand Journal of Zoology, that she recorded 3300 selfies of different animals. In amongst the 530 selfies of different birds, 280 selfies of rabbits and hares that there were 80 selfies of cats. Most of these images (66) were of seven different domestic cats. The other 14 images contained pictures of 7 different wild cats. Cara was able to estimate a density of wild cats at just over 1 per km2, which is at the lower end of wild cat densities recorded.
Most of the domestic cats were found close to the urban border of the park. Pets do go into wild areas but only sometimes and perhaps not too far. They don’t want to miss their regular meals. The wild cats were further from the urban area and deeper in the park. Wild cats, as individuals, are likely to cause more destruction than domestic cats as they need to hunt to live. Knowing where they are helps us to figure out ways of controlling their population and making wild areas safer for native species.
I’m pleased that photos can be so useful. Cat selfies, along with other mammal pest selfies, are a great tool that we are only just starting to appreciate. As we get better at setting the cameras to best take the photos we will continue to see the advantages of this approach for making the world a better place. Let’s hope that a few more of those trillions of photos are taken by trail cameras in the future.