Wednesday, December 7, 2016

Impact of food on an ambush specialist - the Puff Adder

The puff adder, Bitis arietans.
The effect of food availability on the spatial ecology of snakes  is under studied. Snake are low-energy specialists, particularly species that specialize in ambush foraging.  Ambush specialists can feed infrequently and  endure long periods without food. Because they have low-energy requirements, one possible tactic for feeding may be to simply ambush for longer periods when prey availability is low, and decrease the potential costs associated with locating new ambush sites. In a forthcoming paper Glaudas and Alexander  (2017) used radiotelemetry, supplemental feeding, and remote video cameras on free-ranging male puff adders (Bitis arietans) in South Africa to test the hypothesis that food intake affects the foraging ecology of extreme low-energy, ambush foragers. They also quantified their natural feeding rates. Supplementally fed puff adders improved their body condition, spent less time foraging, and decreased distance traveled compared to control snakes. However, movement frequency and home range size did not differ between the two groups. These findings indicate that control snakes traveled farther within similar-sized home ranges compared to fed snakes and did so at no survival cost. Further, naturally foraging puff adders successfully caught a prey of small size once every 10 days on average. Hence, despite their “sit-and-wait” foraging strategy and their low-energy intake/requirements, underfed puff adders travel widely to presumably find appropriate ambush sites that maximize prey capture. This study provides the first strong evidence that the spatial activity of a terrestrial vertebrate species with extremely low energetic demands is significantly affected by
food intake.

Citation

Glaudas X, Alexander GJ. 2017. Food supplementation affects the foraging ecology of a low-energy, ambush-foraging snake. Behavioral Ecology and Sociobiology. 71(1):5.

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