Mapping the Sasquatch

ResearchBlogging.orgI love modeling! I love modeling! Modeling will solve everything!

Let’s model the spatial distribution of Bigfoot!


Figure 1 from the paper. Foots denote sighting of Sasquatch footprints. Circles for just visual/auditory sightings. I ask, how does one know what Bigfoot sounds like?

Yes, it sounds silly, but in the current issue of the Journal of Biogegraphy, Lozier et al give us their stunning contribution Predicting the distribution of Sasquatch in western North America: anything goes with ecological niche modelling. Finally, all will be revealed. And for those wondering:

Sasquatch belongs to a large primate lineage descended from the extinct Asian species Gigantopithicus blacki, but see Milinkovich et al. (2004) and Coltman & Davis (2005) for phylogenetic analyses indicating possible membership in the ungulate clade.

They do this to prove a point – that Ecological Niche Models for determining species ranges are amazing – invaluable conservation tools, really. But if the taxonomy on the data that goes into them are shoddy (like, say, calling a Black Bear a Sasquatch), the results will be, well, interesting.

They use data on sightings (see Fig. 1 above) from… the Bigfoot Field Research Organization
and then used the latest and greatest in Ecological Niche Modeling to determine, given environmental parameters, just where does Bigfoot live? And, under current climate change scenarios, where might we find Sasquatch in the future?

So cryptozoologists take note! Here is a veritable treasure trove of information as to where to place your next tripwire camera!

Where will bigfoot be in the future after climate change? Panel A shows current Sasquatch Distribution. Panel B shows its projected distribution under climate change.

In fairness, the authors use this dubious analysis to point out that, when we have a record of species occurrences that seem tidy and orderly, we often don’t question their taxonomic validity. The output of these models, vital to some conservation efforts, will only be as good as their input. Indeed, in this case, the authors find striking overlap with the (far less frequently observed) Black Bear (yes, people report sightings of Sasquatch more than that of Black Bears). It’s a real problem, and the assessment of data uncertainty is a real pressing issue for any method that attempts to draw inference from sparse data.

But, really, in the end, this is an Ig-Nobel award winner in the making. Bravo.

Lozier, J., Aniello, P., & Hickerson, M. (2009). Predicting the distribution of Sasquatch in western North America: anything goes with ecological niche modelling Journal of Biogeography DOI: 10.1111/j.1365-2699.2009.02152.x

Going Topless with Urchins

There’s nothing so satisfying as pulling back and seeing your brand new experiment out there in the water.

It’s been a crazy week or three getting this up and running, but now my first big postdoctoral experiment is soaking in the water, with urchins grazing away.

I’m testing some ideas regarding how diversity mediates the impact of disturbance by urchin grazing, and vice-versa – how disturbance by grazing can alter diversity. In essence, I’m testing a model of a community feedback process based on a framework whipped together by Randall Hughes, myself, and a few other fabulous co-authors.

But even though your ideas may be high-up and lofty, they always meet some interesting realities on the ground. Reality point 1 – my god, we built a lot of large cages.

This is about 1/4 of the cages before deployment. The rest were in the water. Thank fod for cheerful undergrad labor (fueled by brownies made from scratch – the key is to underbake them, and use a combination of eggs and egg yolks for extra gooey-ness) They look like such simple cheap affairs – some garden fencing, some PVC, some netting around the bottom…and then there’s about 1 ton worth of chain and half a ton of rebar stuffed into them. Subtidal work: unless it’s heavy, the waves will sweep it away.

Reality 2 – sometimes, you’ve gotta do it topless. Yes, the cages have no tops. This would seem the height of insanity if you want to keep something INSIDE. However, urchins appear to not like bendy flexy things. Sure, they’ll crawl up to the tops, but then they get to that wave strip at the margin, and freak out and freeze up. I’ve watched it. It’s kinda odd. And those cages that did have a top on them? That top, even if it’s mesh, creates a LOT of lift. So, a small wave washes by, and suddenly the cage top becomes an airplane wing. Unless you’ve added a huge amount of weight to your cage (see above), you may well never be able to find your cage again.

Reality 3 – nature is variable. Well, duh. See the two cages with two very different species compositions, som providing more or less biomass. I mean, the whole premise of this experiment was to use a natural gradient in species diversity as a treatment. But sometimes adding or subtracting one species can make a huge difference. Sampling (Reality 4 – ID-ing to the species level in the field on SCUBA gets pretty tedious after one hour, let alone 4 or 5) was pretty interesting, showing that large differences were indeed generated by both position on the reef, local topography, etc, as well as whether, say, tiny sea cucumbers had colonized a plot, whether the plot was full of lush Pterygophora, or the presence of the squat thick gorgonian Muricea.

Reality 5 – hungry urchins are hungry. And devious. Upon addition of urching to plots, they zoomed over to any brown algae (particularly the aforementioned Pterygophora or any juvenile giant kelp) and began munching in earnest. Some ran for the sides of the cages (and a few managed to squeeze out – Reality 6, the best laid plans of underwater mice and men… I’ll be doing some replacements this week with larger urchins). But the instand voracious consumption was really quite impressive.

I’m pretty stoked, and deeply curious as to how this will turn out. I’m sure there will be cursing, frustration, and bizarre results in the future, but for now, SCIENCE! Love it!