Optimality modelling in Tempe, AZ

I'm now 5 months into my PhD with the Wilson Performance Lab at the University of Queensland. I've been busy learning about small dasyurids, the effects of environmental enrichment and how to organise the paperwork required for sojourning into the field to collect animals. However, I also had a five week trip to Tempe, Arizona in the USA in February/March, where I did a crash course in modelling.

Towering saguaro (Carnegiea gigantea) and a brilliant blue sky in Lost Dutchman National Park (Sonoran desert).

No, don't worry guys, I haven't had a sudden delusional change in profession - I'm talking about the mathematical kind of modelling, which is mercifully camera-free (though the testing of said models doesn't have to be). I was doing some collaboration and learning as much as I could cram in at Mike Angilletta's Thermal Adaptation Lab at Arizona State University.

A defensively poised Arizona striped-tail scorpion (Paravaejovis spinigerus).

I was really excited about this, and not just because getting to go to the States for the first time was freakin' awesome or because meeting and working with new people is fun, but also because modelling is really, really useful. Not to mention desirable and, frankly, pretty sexy. Being able to model is almost like being that hot supermodel that everybody wants around. At least, that's what I like to tell myself.

Sonoran desert flowers.

What makes modelling so special? Well, it’s basically the process of constructing a mathematical function, or combination of functions, that allow us to predict what an animal (or a cell, or even an ecosystem) will do given a certain set of conditions and assumptions. A mathematical model is never a perfect representation of a biological system, but it does give us an excellent starting point for determining what assumptions are being violated, when they’re being violated, and therefore what we can expect under different conditions. Lots of ecologists avoid modelling because it involves mathematical equations, which is a scary prospect for most of us. Happily, it looks like my toiling through those first year undergraduate maths courses might pay off.

Beaver chewings along the San Pedro river.

While I was in Arizona, I was working on fine-tuning a model that Robbie and Mike started developing to calculate the optimal speed for an animal running from one end of a beam to the other when predators are around. Sound familiar? This sort of optimality modelling was part of what we did for our study on optimal serve speed in elite tennis players. This time, we were trying to find a model that predicted how fast an animal should run along a beam to minimise it's chance of slipping while maximising it's chance of outrunning the predator. In theory, this problem sounds fairly simple, but what is tricky is figuring out what matters and what doesn't, and learning how to program the model to do what you want it to (I'm using Python at the moment). I've still got a bit of debugging to do before the model is ready for testing, but getting stuck in was easier than you'd think!

A fishhook barrel cactus hanging with some hedgehog cacti.

In between learning some cool new techniques and becoming awesome, I got to do some sight-seeing and obsess over some new birds and reptiles. I went for a hike in the Sonoran desert at Lost Dutchman National Park, went birding at San Pedro House, attended my first American college party and checked out downtown Phoenix without splurging on some fantastically cheap jeans – and, to top it off, some of the lab took me camping at the Grand Canyon. Has anybody told me that I'm a lucky bugger? Why, yes. I'm not complaining!

A desert marigold (Baileva multiradiata) in the Sonoran desert.

I'd like to say a massive thank you to Robbie and my lab for sending me over there, and of course to Mike and his lab for having me. It was a fantastic experience, and hopefully the skills I learned will be useful to everyone. I'd also like to thank my awesome Arizona roommates for letting me tag along with them to various places, and just a giant thank you all around to everyone I talked to for being so friendly and welcoming!

The Grand Canyon.

All images by Rebecca Wheatley unless otherwise credited.