Its easy to assume that wild koalas have small, reliable home ranges. After all, you don’t see them moving about much do you?
If we’ve learnt one thing over 17 years of wild koala research, its that koalas move! A lot!
We first met Cruiz in November 2008 in the Turntable region of the You Yangs. He looked big, strong and healthy. We assumed he was mature – at least 4 or 5 years old. It was exciting to have a new male on the block.
But then he disappeared. Sadly, we filed his photos and nose pattern diagram under the “Koalas once seen, never to be seen again” file.
You should never give up on a koala, though. Out of the blue in December 2011 he re-appeared in the turntable area. He’s back, we thought. “Don’t be hasty” he thought.
We didn’t see Cruiz once in 2012. Not once. Back into The File he went.
So when he showed up three times in 2013 and three times in 2014, we had learnt our lesson. We didn’t get excited. Maybe he’s a nomad. Maybe he’s in protracted negotiations with dominant male Anzac, and other residents Vincent, Zack, Kenny and Rocky.
But 2015 was a good year for Cruiz. Already we have seen him 12 times. He’s been all over the place – turntable, branding yard 2 km to the east, Branch Rd. If we simply join the dots of all his locations this year, his home range would be around 117 hectares!
Interestingly, too, he isn’t migrating steadily from one area to another – he is regularly traversing that entire area. One day he’ll be in Branding Yard, a week later he’ll be back in Turntable.
He’s not young either – we estimate he is at least 12 years old. That’s a really good age for a wild male these days.
Every single wild koala is different. Cruiz is a special fellow.
Koalas can be easily and non-intrusively identified by the natural black and white markings inside their nostrils. These markings, ‘the nose pattern’ appear to stay the same throughout life, so can be a useful and reliable identifying feature. Over a 16 year study, monitoring 108 individual koalas in three locations, no two koala nose patterns have ever been seen to be identical, and no nose pattern has been seen to change substantially.
Step 1. Take a photograph of a koala’s nose. The best identification photos are taken from front-on and slightly below the koala. The focus should be on the nostrils, in good light (not too much shadow or contrast) and as close-up as possible.
Step 2. Look at the white/pale pattern inside and around the nostrils. This is the ‘target area’ where the nose pattern exists. See the area inside the pink outline in the image below. Markings outside of the target area can vary throughout the life of the koala, so should be noted, but should not be relied upon for identification.
Step 3. Compare the first koala (Truganina) to this koala below (Pat). Look just at the target area – can you see the differences?
Below is a comparison of the two koalas nose pattern target areas rotated to the same angle. Truganina on the left has a lot more white in her nose pattern. The white extends outside the nostril area in a few places, with a messy outline. Her lips have a lot of white too. There are black spots in the white. Pat, on right, has a simpler nose pattern. The white is almost totally confined inside the nostrils. The pattern has a scalloped edge.
Step 4. Record the pattern. There are three ways you can record nose patterns. Use just one, or two in combination, whatever works for you. We use all three methods in tandem, and it works well.
METHOD 1: File the photograph in a folder on your computer for quick reference in future. Compare each new koala photograph to the existing photographs until you achieve a match by eye. These two photographs below are of the same koala, Truganina, 5 years apart. Can you see the match? This method works if you can see the match easily, and if there’s not a lot of koalas to choose from. It will help if you file carefully, and keep a record of each koala seen (see Tips below on how to do this)
METHOD 2: Trace the nose pattern with tracing paper over a printed photograph. This method is perfectly valid, quick and easy especially if you’re not computer savvy, or don’t have a lot of time. Take a photocopy or scan of your diagram, keep it handy in a binder to check against future photographs of the same koala. We still use this method as it is the quickest and handiest way to keep up to date.
METHOD 3: Use a computer graphics program. This method is useful if there are several people using the method on the same koalas, or if you are not confident of making the comparison by eye. Simple graphics programs will do the job. Photoshop or Paint Shop Pro are fine – use the layers tools.
Powerful programs like GIMP are good too. The image below shows three nose pattern diagrams, created with GIMP, of the same koala nearly 5 years apart. Yellow layer = December 2013, pink layer = December 2013, blue layer = February 2009. The similarity is astounding, particularly considering that the the nose is a soft tissue that changes shape.
It helps to come up with a photo file name protocol that you use the same way each time. You can name the image with the koalas name or number and date eg. K1female120515 (first female sighted on 12th May 2015).
If you regularly see koalas in a number of locations, it might be good to separate the nose pattern photographs from different locations, and by sex by folder. ie Nose Patterns – YouYangs – females.
Record keeping will help! Keep a record of when and where a koala was seen. You can do this in the image (EXIF) information on the photo, or in a simple (or detailed) datasheet – examples below:
Side-on photographs, or photos from extreme angles can distort a nose pattern. If possible, wait or move to get a front-on view. This image below is Truganina again, but at an angle. You can still see her distinctive nose pattern in her right nostril, but the left pattern is obscured.
Deep shadows under the nostril ridge, or strong light, can hide the nose pattern. Photograph with several different settings on your camera when light is strong. In the beautiful photo below, Cloud’s nose pattern is almost completely lost in shadow. Brightening the image on a computer graphics program may reveal the pattern.
Flaring and closing of the nostrils can appear to change a nose pattern, but in a predictable way. Look closely at the nostril shape in your photograph to determine whether the nostril is flared or closed.
This method was discovered in 1998 and documented by Janine Duffy, President of the (brand new!) Koala Clancy Foundation and founder of Echidna Walkabout Nature Tours. We have more details if you need them, or if you have tips or observations to add please contact firstname.lastname@example.org. We will credit you!