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Physical therapy: When the cobra spits

Physical therapy, as a field, gains a bit of danger-flecked glamor from this new study — specifically from the fact that one of the cobra-comprehending co-authors is in a university department of physical therapy. The study is:

Bruce Young

Target tracking during venom ‘spitting’ by cobras,” Guido Westhoff, Melissa Boetig, Horst Bleckmann and Bruce A. Young, Journal of Experimental Biology 213, 1797-1802 (2010). (Thanks to investigator Katherine Meusey for bringing this to our attention.) Corresponding author Young is at the Department of Physical Therapy, University of Massachusetts Lowell. The other co-authors are at the University of Bonn, Germany and at Washburn University in Tokeka, Kansas. The team reports:

Spitting cobras, which defend themselves by streaming venom towards the face and/or eyes of a predator, must be highly accurate because the venom they spit is only an effective deterrent if it lands on the predator’s cornea. Several factors make this level of accuracy difficult to achieve… In the present study we show that spitting cobras can accurately track the movements of a potentially threatening vertebrate, and by anticipating its subsequent (short-term) movements direct their venom to maximize the likelihood of striking the target’s eye. Unlike other animals that project material, in spitting cobras the discharge orifice (the fang) is relatively fixed so directing the venom stream requires rapid movements of the entire head. The cobra’s ability to track and anticipate the target’s movement, and to perform rapid cephalic oscillations that coordinate with the target’s movements suggest a level of neural processing that has not been attributed to snakes, or other reptiles, previously.

BONUS: Language Log dissects some of the study’s language.

Improbable Research