My dissertation is focused on gap crossing in flying snakes and their relatives. Gap crossing behaviors encompass a wide range of animal movements: pretty much any behavior that takes an animal from one support to another across some type of empty space. Gap crossing is particularly relevant for arboreal animals, where moving between branches is required to navigate the canopy.
There are three reasons to be particularly interested in gap-crossing in flying snakes. The first is mechanical — how does a legless animal launch a jump? In the study of biomechanics, jumping has received a lot of attention, but almost always aimed at animals with legs. A legless jumping strategy might have a completely different set of advantages or limitations to legged jumping.
Secondly, flying snakes have an incredibly diverse array of movement behaviors: they can crawl, climb, swim, jump, and glide. Many animals are more restricted: by specializing in flight, for example, most birds are not suited to long-distance running. The snake manages to accomplish all these movement strategies with an incredibly simply body. Examining how flying snakes move (especially in comparison to other snakes, or other gliders) can help scientists understand how the requirements of performing different behaviors might interact and trade-off with one another. For example, do snakes that glide climb just as well as non-gliding snakes? Or do some of the adaptations that enable them to glide cause them to pay a cost in terms of their ability to do other types of movement?
Besides being intellectually interesting, a better understanding of flying snake movement in general, and legless jumping in particular, could help people come up with ideas for movement strategies for robots. The ability of snakes to move in a lot of different ways is particularly relevant, as robots today tend to be specialists: the Wildcat robot is amazing at running but probably not much for swimming. Flying snakes manage to perform a wide range of behaviors without changing shape or having any particular gliding appendages (although they do flatten into basically a ribbon when they glide), which might make them a particularly interesting source of inspiration.
Finally, jumping is a very common behavior among most arboreal animals like lizards and primates, but very rare among snakes. It might be that evolving the ability to jump has significantly influenced the ecology of these snakes: how much they travel, what habitats they can explore, what they eat, etc. It can be hard to compare the effect of jumping on ecology between different groups of species, because there are so many other factors like body size or evolutionary history. If I compare the feeding habits of a non-jumping primate, like a slow loris, to a very jumpy primate like a gibbon, there are so many factors besides the ability to jump that could explain the differences. Yet the flying snakes and their relatives make a really interesting group, because there are three closely related genera with three different sets of behaviors: the flying snakes, that can both jump and glide, the bronzeback snakes, that can only jump, and the Asian vine snakes (Ahaetulla) that can’t do either. The close genetic relationship and relatively similar habitats of these snakes decreases the number of variables involved in these comparisons, and means that there is some hope of being able to tease out the influence of jumping and gliding on the ecology of these species---although it still isn't particularly easy.
Anyway, all three of these areas are really huge research topics, but my work will maybe set up a bit of the ground work. Since this has been super wordy let's finish with a slow motion video of a flying snake crossing a gap.