9 May 2013

Thorny devil

Escher meets Ouroboros. Armadillo girdled lizard, southern Africa
Chapter 20: Thorny Devil

Page 297: analogous systems...in other arid places. Old growth forest in Tennessee is not exactly arid, but for some creatures there moisture is hard to find. In The Forest Unseen, David George Haskell notes:
Dehydration is the [lone star] tick's main foe during their quests [for blood]. Ticks sit in exposed locations for days, even weeks, waiting their hosts. The wind whisks away moisture, and the sun bakes their small leathery bodies. Wandering off in search of a drink would interrupt the quest and, in many habitats, there is no water to be found. So, ticks have evolved the ability to drink water from air. They secrete a special saliva into a grove near the mouth and, like the silica gel that we use to dry our electronic gadgets, their saliva draws water out of the air, the ticks then swallow the saliva, rehydrating themselves and continuing the quest.

This is the twenty-first in a new series of notes and comments on chapters in The Book of Barely Imagined Beings. It appears around the time of the US publication, and adds to an earlier series that appeared around UK publication.

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