The following time-series of photos, shot on 16 March 2016 during a photowalk along the Hike-Bike Trail at Huntley Meadows Park, shows a Common Ribbonsnake (Thamnophis sauritus sauritus) eating a Southern Leopard Frog (Lithobates sphenocephalus).
Although the amphibian looks similar to Pickerel Frog (Lithobates palustris), I tentatively identified the species as Southern Leopard Frog based upon one of two field markers that were visible: distinct dorsolateral folds that extend the full length of the body (shown); a distinct white spot in the center of the tympanum (not shown). Sincere thanks to Alonso Abugattas — Natural Resources Manager, Arlington County Parks, Virginia — for verifying my identification.
As shown in the first photo, the snake had a fatal grip on the frog by the time I spotted the pair.
Notice the small green bubble, located on the frog’s dorsal posterior, that is visible in the second and third photos. I consulted the experts of the Virginia Herpetological Society for help in identifying the bubble.
The general consensus is the cloaca (a bag through which reproductive- and waste products leave the body) is inverted and protruded through the anus due to the internal pressure the snake is putting on the body cavity. If the frog were a female in reproductive condition, it could also be either eggs (unlikely due to color) or jelly being forced out, again due to pressure. Source Credit: John, Virginia Herpetological Society.
Just as I thought — the snake was actually squeezing the guts out of the frog!
Copyright © 2016 Walter Sanford. All rights reserved.