Strike and a Miss

Below is an awesome screenshot from one of our field recordings. In it, Greeata, a female rattlesnake strikes at an adult squirrel that has been harassing her for the past two minutes. The blue arrow is pointed at Greeata's open mouth as she lunges her head out of the log. The orange arrow is pointed at the squirrel's head as it dodges the snake strike. 

This screenshot is intriguing because we rarely observe strikes on squirrels that are actively harassing snakes. This is because squirrels are more likely to evade a strike when they are aware of the snake's presence and snakes don't want to waste time and energy on a strike that will be unsuccessful.  This poses the question, why did Greeata strike at this squirrel? Was it a defensive strike rather than a predatory strike? She should have known her strike would be a miss and saved it for another day. One aspect of rattlesnake behavior that I am particularly interested in is the inter-individual variation in strike reactivity. There may be a continuum of behavioral types where some individuals are more judicious, strike less often, but have better strike accuracy while others are more reactive, strike more often, but have less strike accuracy. I hope to capture more snake strikes to analyze this fascinating aspect of rattlesnake hunting behavior.