Species Spotlight Vol. 16

by Jordan Gray 

Turtle Survival Alliance

Alligator Snapping Turtle (Macrochelys sp.)

Countries of Origin:  United States of America

IUCN Status:  Vulnerable

Estimated surviving population:   Unknown

Habitat: Rivers, creeks, spring runs, bayous, oxbows, river swamps, reservoirs

Biology and Habits: Alligator Snapping Turtles are a benthic dweller of the waterbodies they inhabit, typically favoring the deepest part of the waterway. They are most active during the night when they may traverse through their home range actively feeding and scavenging. This species feeds on carrion, fish, reptiles (including other turtles), amphibians, arthropods, mollusks, annelids, mammals, and aquatic vegetation. During the day, this species is highly inactive, and may sit motionless on the bottom of the water column for hours at a time. However, they have evolved a unique adapation to still feed while relatively inactive. Equipped with a worm-like appendage in their mouths, this turtle will sit motionless in the water, moving the "lure" to attract prey such as fish, which it will bite down upon once inside the widely-opened jaws. A solitary species by nature, the Alligator Snapping Turtle has an average home range of just under 0.80 km, of which it typically uses a submerged object to define the core of its range (Riedle, et al., 2006). Individuals may however make considerable movements of several kilometers up and downstream from its home range. An obligate aquatic, this species rarely leaves the water except to lay eggs, or if displaced by flooding events. Females will migrate to nesting sites tens of meters away from the waterline to deposit up to 50 or more eggs.

Size:

  • Males ‚⧠80 cm (31.5 in)
  • Females ‚⧠50 cm (20 in)

Factoids:

  • The Alligator Snapping Turtle is divided into two separate species: The Western Alligator Snapping Turtle (Macrochelys temminckii) and the Suwannee Alligator Snapping Turtle (Macrochelys suwanniensis)
  • The Alligator Snapping Turtle is one of the largest freshwater turtle in the world
  • The largest specimen on record was a captive specimen of 107 kg (236 lbs)
  • Alligator Snapping Turtles are estimated to live up to 200 years
  • Despite its menacing appearance, this species is not aggressive, but will actively display a gaping mouth when molested
  • The worm-like appendage in its mouth may be different colors depending on the genetics of the specimen, ranging in color from whitish, to pink, to pale grey, or brown
  • Alligator Snapping Turtles use chemosensory cues to locate prey items. They use gular (throat) pumping to draw water in and out to sample the surrounding water for chemicals that have been released by prey species (Punzo and Alton, 2002)
  • The large, powerful jaws of this species can exert a bite force of 1000 psi
  • This species was heavily hunted for commercial and personal consumption in the past leading to localized and range-wide population declines. It is now protected from hunting in every state in which it resides, with the exception of Louisiana, where one individual may be collected per day for personal use

Greatest Threats: Poaching for consumption, to stock breeding farms, and for illegal commerical transport, fishing gear entanglement ‚Äî especially trotlines, waterway channelization, alteration, riparian destruction, and damming

How you can help: The greatest persistent threat to this species range-wide is fishing equipment lost or discarded in the waterways in which they live. Weighted trot-lines pose a significant threat to even the largest of specimens, who can drown if they cannot become untangled. You can help this species by always discarding fishing tackle and line in the proper receptacles and by educating others to do the same. Furthermore, participating in river cleanup efforts will help regularly reduce the threats posed by discarded tackle and line.

Our TSA-North American Freshwater Turtle Research Group is actively involved in studying this species in the bayous of Harris County, Texas. You can aid this group in their research and conservation efforts for this hidden, yet iconic riverine species, in one of the most populous counties in the United States by DONATING TODAY!

Photo Credit: Jim Olive