Robotic Squirrels Battle It Out With Rattlesnakes

Hugh Pickens writes "Alasdair Wilkins writes that when a squirrel encounters a rattlesnake in the wild, it does something very peculiar to survive its brush with the predator — something is so peculiar that scientists are building robotic squirrels just to try to understand the behavior. A live squirrel does two things when it sees a rattlesnake. It starts moving its tail in a flagging motion and actually heats up the temperature of its tail. Because rattlesnakes can see in the infrared wavelengths, they should be able to see both the tail move and heat up. The question is which of these two signals is important and just what message it's supposed to send to the rattlesnake. To that end, engineers at UC Davis have built robosquirrels, which allow the biologists to simulate the two squirrel behaviors one a time and the research so far suggests it's the heated tail, not the flagging motion, that the snake responds to, making it one of the first known examples of infrared communication between two distinct species. 'Snakes will rarely strike at a flagging adult squirrel — and if they do they almost always miss,' says Rulon Clark, assistant professor of biology at San Diego State University and an expert on snake behavior. 'In some cases, it seems the rattlesnakes just decide it's best to cut their losses after dealing with these confusing critters,' adds Wilkins, 'as sometimes the snakes just leave the area completely after encountering these flagging, tail-heating squirrels.'"

Re:I guess two reasons ...

[Captain Hook]

The article also said that the snake almost never struck at the flagging tail and if it did it normally misses.

That suggests the tail is being heated up to make it a more inviting target and the movement is there to ensure that the snake never get a chance to actually strike (which presumably would still kill the squirrel unless it can cast off the tail/shutdown all blood flow before the poison makes its way into the core organs). I assume the tail can be moved far more quickly and erratically than the squirrels main body mass.

It sounds to me more like a matador using a cloak as a target for the bull. Something to draw the attention in a way which encourages an attack (or at least preparation for an attack) at the point which has least chance of causing damage.

Re:The squirrels are even cleverer than that

[itmo]

wikipedia: "The nerve fibers in the pit organ are constantly firing at a very low rate. Objects that are within a neutral temperature range do not change the rate of firing; the neutral range is determined by the average thermal radiation of all objects in the receptive field of the organ. The thermal radiation above a given threshold causes an increase in the temperature of the nerve fiber, resulting in stimulation of the nerve and subsequent firing, with increased temperature resulting in increased firing rate.[9] The sensitivity of the nerve fibers is estimated to be >0.001 C.[10]" So assuming I fill up your sight picture with a moving heat source which will cause the average temperature of the whole area to rise. Will that not mess up your contrast by making your signal show up less from the average? So by filling up the field of visiion with a heated moving tail, they are actually making their body show up less. So what the snake sees is a confusing , low contrast blob of heat.