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Apologies, right up front, to fans of Eli and his antics, because this is another turtle post. In my defence, enough people have commented on how funny our 'non-shrimp-eating' turtles are, that I think it is only fair that I defend their honour and update their status to predators in our tank now that they've been exerting some top-down pressure on the crayfish (apologies for the top-down term - it just means that the turtles have eaten a few - but I am a food web ecologist after all). As you may recall, we recently bought 10 'feeder' crays and much to my distress, the turtles hadn't fed on any of them. Some have actually grown quite a lot, by virtue of their apparent fearlessness and hunger for the turtle food, as you can see in some of these photos.
But that all changed on Tuesday, when we got home and discovered Zoomy tucking into a crayfish tail!
Eli and I have since checked the tank to see how many crayfish are left (by lifting up the log most of them live under) and we think that the population has been cut by five, which means the turtles probably won't need quite so much frozen food tomorrow morning (although they always seem hungry!). As an aside, I am, perhaps a little ambitiously, actually hoping that this experience will teach Eli not only a few things about life and death in the animal world but also a few things about subtraction...one can only hope. At least he hasn't been distressed by the loss of a few crayfish, we both actually found it highly entertaining!
A couple of weekends ago we re-visited our favourite pet store to top up our supply of frozen turtle food. While we were there having a bit of a look around (it's just like going to a zoo, minus the admission fee, so we always make the most of our visits!), we decided that it might be a good idea to buy some live food too, so off we went to the aquarium section. Figuring that our two turtles would really like munching on small crayfish ('feeder crays'), we bought 10 of them and headed home.Now this calculation of mine turned out to be wrong, for a couple of reasons. First, the feeder crays really liked their new lodgings and after looking around for a little while, they started making themselves at home by hiding in the nooks and crannies around the logs we have in the tank and by excavating small burrows in the gravel. Here are some shots of the feeder crays becoming familiar with their new surroundings...
Second, although it is true that our turtles were interested in the new arrivals, it was soon clear that they didn't quite know what to do with them, which leads me to reason number three - it turns out that live food with claws are quite good at defending themselves, so our turtles soon learnt that the feeder crays did not represent an easy meal. These shots show what a typical early interaction between the crays and the turtles looked like - the turtle approaches carefully, often from behind, before retreating hastily after being nipped!
Fast forward a few more weeks and we now have turtles and feeder crays as pets. Although our turtles have grown, so too have the feeder crays, and, coupled with their feisty personalities I think it is now pretty clear that they're not going to get munched anytime soon.
The outcome of this miscalculation of mine isn't so bad though, because feeding times are now even more exciting to watch. Not only are the turtles desperate to get as much food as possible before it is intercepted by the feeder crays at the bottom of the tank, but they also have to watch out for the occasional nip!
I'm still hoping that the turtles will eventually get the idea and maybe even team up to 'take care' of the feeder cray problem, but for the moment (and while they're still small enough to hide out in the tank) the feeder crays seem to be content in making a home for themselves in our tank. Stay tuned...
Earlier this week Eli and I went on a field trip. The intention was for us to watch horses walk through some creeks in the Gold Coast hinterland - part of a project I am involved in which aims to investigate the impacts of horse riding in streams in protected areas. Eli, a big fan of both horses and days off from daycare, was primed to help me out with my work, so off we headed to the upper reaches of Tallebudgera Creek.We arrived to meet Jo and Pete, some of our colleagues from the Department of Environment and Resource Management (DERM), only to find out that the horses weren't coming - apparently the weather was just too hot (we were expecting a 35 C day) and the riders weren't prepared to saddle up their horses and cross the creek (despite the obvious benefits to the horses in walking through a nice cool rainforest stream). Thankfully, Eli wasn't too upset about this change in our plans - he just said that 'we saw some horses on the way here' and was happy enough with that. Jo and Pete drove their 4WD across the stream a few times, so at least we could examine the impacts of something crossing the stream, and then they headed off to another site. As for us, well we wanted to make the most of our trip so we stayed behind, got into our togs, and started exploring!
An added incentive, at least from my perspective, was that I'd just bought an underwater camera and wanted to test it out. Here are some pics of the bits of Eli that were immersed...
Of course an underwater camera is also good for photographing stream habitats too, so please indulge me for just a few more photos...
We spent about two hours in the stream, picking up cobbles and looking at aquatic insects, throwing the occasional rock into the deep pool (we are boys after all!) and enjoying the cool clear water. 
Eli and I particularly liked spotting these bright blue damselflies, the Arrowhead Rockmaster (Diphlebia nymphoides) and the Sapphire Rockmaster (Diphlebia coerulescens), respectively. 
And here Eli is becoming acquainted with a newly emerged adult mayfly, his first.
After talking up this field trip adventure with his daycare teachers, we had to find a few things that we could take home with us that Eli could present as 'news' the next day. Although we collected a lot of live aquatic insects, including a very hyperactive whirligig beetle, Eli was happy to return them to the water. For his daycare presentation, Eli collected some red leaves that had fallen into the stream and I picked up a few exoskeletons (like those pictured below) from recently emerged aquatic insects (that would hopefully make the journey home in one piece). 
After a couple of hours in the water we were getting a bit pruney, so we hopped out and had a nice picnic lunch. Eli was pretty keen to stay at the creek, but I pitched to him the idea that we could go down to the mouth of Tallebudgera Creek, near the ocean, for a swim - and he leapt at the chance. About 20 minutes later we were in the water again, this time for a swim and run around on the beach.
Here are a couple of funny shots of Eli in the Tallebudgera Creek estuary - in the first he is mostly underwater and in the second you can see what his hair looked like immediately after the underwater shot. 
All in all, and despite the lack of horses, we had a great day. Another difficult day in the office for me...makes me wonder what Eli thinks I do for a job now?