Satiety and eating patterns in two species of constricting snakes

Satiety has been studied extensively in mammals, birds and fish but very little information exists on reptiles. Here we investigate time-dependent satiation in two species of constricting snakes, ball pythons (Python regius) and yellow anacondas (Eunectes notaeus). Satiation was shown to depend on both fasting time and prey size. In the ball pythons fed with mice of a relative prey mass RPM (mass of the prey / mass of the snake × 100) of 15%, we observed a satiety response that developed between 6 and 12 h after feeding, but after 24 h pythons regained their appetite. With an RPM of 10% the pythons kept eating throughout the experiment. The anacondas showed a non-significant tendency for satiety to develop between 6 and 12 h after ingesting a prey of 20% RPM. Unlike pythons, anacondas remained satiated after 24 h. Handling time (from strike until prey swallowed) increased with RPM. We also found a significant decrease in handling time between the first and the second prey and a positive correlation between handling time and the mass of the snake.

Research Highlights
► A time-dependent satiety signal develops between 6 and 12 h in ball pythons.
► The satiety signal is highly dependent on relative prey size.
► A threshold seems to exist above which the snakes refuse to eat additional prey.
► Significant faster handling time is observed when offered a second prey.