The Discovery Channels in the UK and the US recently have aired documentaries called “Dino Gangs” that follow dinosaur paleontologist Philip Currie around the globe (Alberta, Mongolia, Indonesia, South Africa, Great Britain), including little Athens, Ohio, the home of Ohio University. “Dino Gangs” addresses Currie’s theory that tyrannosaurs hunted as cooperative, social packs. Phil and the film crew from Atlantic Productions were here to talk with me about my work with Ryan Ridgely on tyrannosaur brains and sensory capabilities…basically whether tyrannosaurs had the mental wherewithal to pull off pack hunting. Phil Currie and his collaborators have published a few articles that have alluded to the possibility of coordinated, social, pack hunting, mostly notably his 1998 article in Gaia. My goal here is neither to evaluate the nuances of his arguments (e.g., the taphonomic issues) nor to address the media hoopla from the folks at Atlantic, the same folks who brought us Darwinius and Predator X (check out Brian Switek’s thoughtful response). My goal is simply to relate what went on here in Athens and to clarify how I think tyrannosaur neuroanatomy fits into the argument.
Another documentary crew comes to town
We get asked to participate in a lot of documentaries in part, I think, because our work is so visual and interactive (and I like to think also of some significance). Typically, crews come in for a weekend (scheduled to minimize disruption of our normal work), and then they leave. Maybe we’ll later cook up some HD visualizations for the production, but basically our involvement is limited to our own stuff. As I blogged about earlier, TV documentaries have become a normal part of our broader outreach plan, allowing us to reach millions with our research. The “Dino Gangs” program fit right into the normal pattern. I was approached by producer Martin Pupp, who introduced the project and told me about Phil Currie’s involvement. We talked about what my team had done and whether there’d be anything to film here. I saw it as an opportunity to the take the message (and 3D visualizations) of our then new-ish 2009 article in the Anatomical Record on tyrannosaurid brain and sensory systems to a mass audience—NSF’s Broader Impacts writ large. It was also an opportunity to have one of my heroes, Phil Currie, actually visit my lab and meet with our people. Win! They came in April 2010, and the shoot was a total blast! We not only shot in my lab, but we also went to O’Bleness Memorial Hospital where we did some “faux scanning,” recreating the scan process for the cameras with the help of Heather Rockhold, Chief CT Technologist. I recently put up an album of “behind-the-scenes” photos from the shoot on our WitmerLab Facebook page.
The “Dino Gangs” documentary: two releases, two rather different shows
I enjoy making the documentaries as much as I dislike watching them. Some of the latter comes from the normal aversion to hearing and seeing one’s self (definitely the downside of big-screen HD TVs!), but also there’s the inevitable disappointment of the compromises that plague science documentaries on commercial networks. They need to capture and hold an audience. I thought “Dino Gangs,” on the whole, wasn’t too bad, given the constraints of the genre. The narrative of Phil Currie’s quest for evidence to support his pack-hunting idea is quite compelling. Some decent science was presented, and the live-action elements were visually striking, although the CGI animation wasn’t the best. The UK and US versions differed, however. The most obvious difference was in length: a two-hour UK version versus just one hour in the US. But far more significant was the difference in stance. What they cut out of the US version was basically the dissenting view. In the UK version, there is hearty skepticism from, for example, Dave Eberth on taphonomic grounds and Don Henderson on almost all possible grounds (clearly Don ain’t buying it at all). These skeptics, as well as other scientists in the UK version such as Roger Benson, Lou Jacobs, and John Hutchinson, are basically absent in the US version. So the Brits were left with a more balanced view than were we yanks.
So, what DOES the brain tell us about pack hunting?
They cut a key element for the US version from the segment where Phil and I sit face to face and discuss tyrannosaur brains. Phil asks me whether brain endocasts can “actually say anything about the social behavior.” I responded, “I wish what we could do is actually point to a ‘cooperative hunting lobe’ of the brain…sadly, it doesn’t really work that way.” Externally, the brain of the cooperatively hunting lion is virtually identical to that of the solitary hunting leopard. The best we can do is to look at overall cerebral size, compare to modern animals, and make some rough estimates. In my opinion, tyrannosaur brains were large enough to have engaged in communal hunting, meaning hunting in groups…but not necessarily hunting truly cooperatively or socially. In communal hunting, each animal attacks as an individual, but the collective attack helps each individual. Communal hunting could be a step toward cooperative hunting. The producers chose not to present that subtle distinction in either version. My expectation is that, like most things in nature, it’s a continuum from solitary to cooperative hunting, with communal hunting being somewhere in between. For me, the key criterion for social pack hunting is that an individual forgoes immediate benefit (getting a meal now) knowing that its actions (say, driving prey towards others in the pack) will increase its chances of benefiting later once others in the pack have made the kill. Could tyrannosaurs or other dinosaurs been cooperative hunters? Sure, but we can’t say that based on brain endocast structure alone. That said, there’s nothing in the brain endocasts that disprove cooperative hunting. But as for communal hunting, I have a hard time believing that tyrannosaurs wouldn’t have exploited the opportunity to join others in making a kill…it would have decreased individual risk and increased chances of success.