Caution: Animals may bite

So the past 6 months have been absolutely manic as many people may have known. For those of you who don't know the reason, it was possibly the worst kept secrets at the vet college. Crocodiles, Nile crocodiles. We had been working with a group of them trying to understand their locomotion across a range of behaviours (see the project website here). What this actually means is we had been trying to get crocodiles to walk, run, turn and jump in a runway or a treadmill (all work fully approved of by both the RVC in-house ethics board, and the UK Home Office). During these activities we were looking at the crocodiles' movements, and to get the best insights we used a combination of light videos, X-rays (to look at how the bones move during locomotion), force plates (to measure the forces exerted by the crocodiles on the ground as they move) and EMG (electromyography - measures muscle activity by measuring their electrical activity).

And when I am talking about working with crocodiles, everyone instantly thinks of the famously enormous ones in the Masai Mara taking on wildebeest. It leads to an abundance of concern (the health and safety people had a field day), which is obviously healthy to have around animals that have dozens of teeth and eat meat. Let me allay fears now, or reduce how impressed you are about my awesomeness as the new Crocodile Dundee, these crocodiles were all small (all less than 2m and 7.5kg, with most less than 4kg). Why would we pick small ones? Besides the health and safety, and the difficulty in working and housing large crocodiles, small crocodiles actually exhibit a wide range of locomotor behaviours, including low walking/belly sliding, high walks, trotting/galloping, jumping, and climbing (ours regularly were found in the foliage added to their enclosures). As crocodiles get bigger, they are unable to perform some of the higher energy behaviours due to their increased weight .

One of the crocodiles looking out of the straight runway through an acrylic end

Crocodile showing off a high walk. Force plates just visible below the crocodile's neck, and the two X-ray systems receiving drums visible in the background.

Our work with them has now ended, and in the end we have something like 150 hours of working with the crocodiles and have collected some incredible data. There will be many months of analysing it, writing papers, and then combining the data into digital models of an "average" crocodile.

X-ray picture of a crocodile skull

However, it was not all smooth sailing. Working with animals is incredibly difficult (see post on felid field work), let alone mostly aquatic animals who tend to enjoy dominance in their environments. This means motivating them to walk (or run) on demand can be difficult. Or often, impossible. As such, we often had hours of crocodiles being nothing more than angry lumps refusing to do anything. This leads to great videos of stationary crocodiles, and increasingly delirious conversations between the people present.

For our data collection we also needed to move the crocodiles regularly from their enclosures to the research area, which undoubtedly meant lots of handling crocodiles. We were trained by crocodile experts in how to handle crocodiles safely (more for our safety than the crocs I think). Inevitably, I was the one who got it wrong one day trying to tape the jaws of our smallest crocodile shut (in the oral history of this story, she was far bigger, and I may have been doing some heroic act to save some small child). The tape slipped and the croc did what crocs do, and bit the nearest thing. Just this time it happened to be my finger. 

All taped up, finger still attached. The healed picture is even more disappointing so wasn't worth showing

No major damage (think cat bite), just a few punctures and a nice cut across the top of my finger which will leave a memorable scar. I had to go to the hospital to get it cleaned up and get my antibiotics. Funnily they had run out of tetanus jabs (in a walk in centre for minor injuries no less), and it has led to health and safety having to write a bunch of new forms (oops).

I have to say this was one of the more interesting and most frustrating parts of my career. However, the work continues on new things! Keep an eye out on the blog for future updates on our research, and crocodile updates.