Page 82 - Reptiles & Dinosaurs (Britannica Illustrated Science Library)
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78 TURTLES AND SNAKES




          Egg Eaters


                                                                                                                               2 to 4 times
                he egg-eating snake is both harmless and common. Its body is about as thick as an
                adult's fourth finger. The egg-eating snake eats bird eggs and hen eggs that are larger                            THE EGG CAN BE THIS
          T than its body. Although it might be confused with a true viper because of its size and                                MUCH WIDER THAN THE
          coloring, it is classified as an oophagous (egg-eating) snake in the family Dasypeltis. Snakes                            SNAKE'S MOUTH.
          in this family are distinguished by special vertebrae that help break the shell of an egg as it
          is swallowed. It selects eggs very carefully, using its highly refined sense of smell to make
          sure that they are not rotten.





          Unique Diet                                                                                                                                                                                   Regurgitation
          These snakes do not find eggs every day, so they                                                                                                                                         4    The snake drags its throat along
          regurgitate the shells to create more space in their                                                                                                                                          the ground and arches its spine.
          stomachs for the eggs they will find in the future.                                                                                                                                           Then it raises its head and expels
                                                                The folds in the snake's                                                                                                                the eggshell by a series of muscle
                                                                mouth hold the egg,                                                                                                                     contractions.
                                                                moving it toward the                     The egg slowly
                                                                throat.                                  enters the
                       1 inch           2 inches
                       (3 cm)           (6 cm)                                                           mouth until it
                                                                                                         is completely
                                                                                                         inside.                                                                                 RHOMBIC EGG-
                                                                                                                                                                                                 EATING SNAKE
                                                                                                                                                                                                 Dasypeltis scabra
          SIZE COMPARISON
          The egg is two to four times wider
          than the snake's body.
                                                                                                                                                                                    Habitat        Southern Africa
                                                                                                                                                                                    Lifestyle      Nocturnal
                                                                                                                                                                                    Reproduction   Egg-laying
                                                               The interlocking scales   Ingestion                                                                                                                     2 feet (70 cm)
                                                               separate when the skin  1
                                                               is stretched.             The snake starts to swallow the egg
                                                                                         in successive motions. The jaw opens                                     It opens its mouth wide
                                                                                         wider and wider, and the skin on the                                     and expels the shell, which
                         The egg is tough                                                throat becomes distended.                                                is rolled into a thin cylinder.
                         and does not break
                         until it reaches the
                         bony spines.
                                                                                    The throat
                                                                                    returns to its
                                                                                    normal position.


                                         15 minutes

                                          THE TIME IT TAKES TO
                                          SWALLOW AN EGG                                      Rupture
                                                                                        2     The egg reaches the esophageal
                                                                                              teeth, which puncture the eggshell;
                                                                                              the head and neck muscles then
                        A valve blocks                                                        crush it.
                        the passage of                                                                                                                                              1 hour         THE TIME IT CAN TAKE TO
                        eggshell                                                                                                                                                                   REGURGITATE THE SHELL
                        fragments.
                                                                                                                                                                                              Dasypeltis
                                                                                                                                                       3     Pause                            The name of the genus of egg-eating snakes. Dasypeltis scabra is
                                                                                                                                                             The food is processed in the digestive
                                                                                                                                                                                              usually gray or brown with darker marks below its back. It has
                                                                                                                                                             tract until the large bulge below the  teeth in its upper jaw, and only three to seven small, rudimentary
                                                                                                                                                             head disappears and the animal returns  teeth in the back of its jaw. Its teeth are no obstacle to ingesting
                                                                                                                                                             to its normal shape. It forces the  enormous eggs.
                                                                                                                                                             eggshell back into its mouth.
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