Saturday, July 21, 2012

A Stick in the Mud

            In 1973, the Endangered Species Act (ESA) was passed by the Nixon administration in order to protect rare and declining wildlife across the country. Without this legislation, many species would undoubtedly be in more trouble than they already are. Since its passing, 28 species have been delisted due to recovery, including the bald eagle, the grizzly bear, and the american alligator (USFWS, Delisting Report, 2012.

As the bane of developers, the ESA stipulates that there cannot be any actions taken to harm populations of threatened (T) or endangered species (E)—threatened meaning is likely to become endangered, endangered meaning in danger of extinction—or the ecosystems in which they reside. It is a rather involved process to get a species listed under federal protection via the US Fish and Wildlife or NOAA, but once protected, there are serious consequences for harming a T&E species.

An adult bog turtle with the mud rinsed off. Notice the orange cheeks.                  

            A current threatened species that I have gotten to work with is the bog turtle (Gleptemys muhlenbergii “Muhlenberg’s Carved Turtle”), which has separate populations in the Southern Appalachian Mountains and the Northeast. Occupying bogs, swamps, and wet meadows, the bog turtle requires slow-flowing rivulets and mucky, organic soil. Their habitat has some of the richest plant diversity, with small bogs or wetlands having over 150 plant species. Because of their habitat requirements, this species has declined as wetlands have been drained, cultivated, and developed.

      A bog turtle nest (above) is usually laid right in the middle of a tussock sedge, so that it can incubate.      
Between predators, weather, and other factors, only about 27% of eggs make it to hatchlings (below).

             Considering bog turtle habitat, it is no wonder the species are declining. Walking through the bogs, one can sink two feet into muck while trying to avoid poison sumac. Surveying for turtles can involve trapping with wire boxes, or, more commonly, probing in the mud. You would never guess that poking around in deep mud will yield turtles. The trick is learning to discern the “thud” of hitting a submerged root from the “thwok” of a rock from the hollow “thunk” of hitting a bog turtle carapace.

Imagine trying to hit that shell through a foot of mud without knowing what exactly you
are hitting. A sometimes frustrating, but rewarding, treasure hunt.

            Once found, the turtles are notched, measured and released so that the overall population can be estimated with mark recapture analysis. If a turtle is lucky, it will get decked out with a radio transmitter. I can’t decide if the transmitter is poorly respected (like a dog with a head-cone), or highly prized (like a geek with the newest gadget). Anyways, tracking and recording the locations of the turtles using radio telemetry help scientists understand how much habitat is required to sustain a population and what type of sub-habitat, or microhabitat, the individuals prefer.

An adult bog turtle with a radio transmitter attached to the carapace.
The transmitter is placed on the side of the posterior so that it does not hinder movement or mating.

            All in all, the bog turtle is a very neat species, burrowing and moving around underneath mud and adding a little character to a rare and unique habitat.

Information on bog turtles taken from studies reported in Turtles of theUnited States and Canada by Ernst and Lovich


  1. They lay eggs in tussock sedge? Holy crap! Did not know that.....

    Wow, now that's a tough way to make a living.

    Great pictures.

  2. Yea, we have found about 6 nests, all located at the top of the tussock sedge. We have one of them caged to prevent predation because it is right next to one of the pathways we constantly walk by. Hopefully I can get a camera trap out in the bog soon, so that we can see what it eating them. Most likely raccoon.