Our guest blogger this week is National Museums Scotland's Andrew Kitchener, Principal Curator of Vertebrates in the Department of Natural Sciences.
One of the biggest challenges to wildcat conservation is identifying them in the first place. Because wildcats can cross-breed with domestic cats, hybrid offspring may look like wildcats but actually be more domestic cat in origin.
How do we know what to protect and what to neuter? Practically, you cannot genetically test all the cats you find in the wild. It’s expensive, requires a hair or blood sample from each cat and takes time to process before you have a result.
However, if you look carefully at a cat’s markings, or ‘pelage’, it gives us a good idea of what’s going on genetically. By using a technique I developed called ‘pelage scoring’, a scientific method of identifying a wildcat from a hybrid, quick decisions can be made in the field. Having said that, it is a specialist skill that requires a lot of patience and practice.
During the first winter survey run by the project, I looked at 1,318 camera-trap photographs of cats over four days. Many were multiple images of the same cat. Indeed this enormous total was for only 16 individual cats from the wildcat priority areas where Scottish Wildcat Action had trail cameras out.
But many of the images were blurred or out of focus, or you could see only part of a head or back, or they were taken at night and they were not very clear. Often it was a bit like looking at cats through dense fog and only nearly being able to see what they look like.
With names like Tarzan, Ned, Homer and Big Fluffy, you can only wonder at what I have been looking at. However, they were all striped tabby-coloured cats with more or less bushy tails. When doing this type of analysis, I look at multiple images of the same cat in the hope that I can see as many of the seven key pelage characters as possible to score their coat markings so that I can attempt to identify each cat as a wildcat or not.
But most often you cannot quite see the shoulder stripes or the tip of the tail or how spotty the flanks or rump are. The number of photos per individual varied from a massive 179 (some cats don’t mind having their photograph taken) to only three (others camera-shy), so it’s not surprising that it can be a struggle.
Of the 16 cats, I could only score seven completely and one I couldn’t score at all. Sadly all the photographs from this particular batch were average hybrids, with only one, Bede, looking as if it might be a good looking cat, but unfortunately none of the 21 photographs showed its shoulder stripes, flank stripes and rump stripes.
Even photographs of anaesthetised cats undergoing health checks in zoos and wildlife parks can be challenging. A recent batch from a collection failed to include the end half of the tails of any of the cats so that I could not score two of the most critical pelage characters, tail banding and tail tip shape. For those who come across a dead possible wildcat here are some top tips:
- Maximum resolution. Try and maximise the size of each photo, so that I can blow it up on screen to show fine detail. A minimum of about 2MB file size is required for each image. These large files can always be sent to me by a file transfer site so you don’t need to rely on emails becoming too big to send
- Good lighting. Try to make sure the cat is well lit, preferably outside, with no shadows falling across the cat
- Smooth fur. Cats that have been handled (or run over) tend to have ruffled fur. Smooth this down by stroking the fur flat so that the markings are more easily seen
- Wet fur. This is a big problem and can make it impossible to see any markings clearly. If possible try and dry the fur with paper towels, but this may well not be practicable
- Take photos of the whole cat from each side (lateral views), from above (dorsal view), and below (ventral view)
- Close-ups. Follow the photography protocol closely and make sure you get all the close-up photos of key areas of the body such as the nape of the neck, shoulder region, root of the tail, etc
- Check your images. Often images are out of focus due to camera shake or they are poorly framed (missing tail tips!). Check all the images so that you can be sure you have recorded its coat markings accurately
- Labelling. If possible, include in each photo a (hand-written) label with a specimen identification no, date, location or other information which helps identify the cat. Rename the image files with key identification information too.
If you follow these simple top tips, you can make sure that all your photos are of high quality and ensure a more accurate identification of the cat in question. And if any one knows how to persuade a wild-living cat to pose properly in front of a camera trap, please let me know.