My #scicomm story is about the eastern hellbender (Cryptobranchus alleganiensis). Aptly nicknamed the ‘snot otter’ (I mean, just look at it), the hellbender is North America’s largest salamander species. Fun fact, it was recently named as Pennsylvania’s state amphibian.
Side note: Before doing research for this post, I didn’t realize state amphibians were even a thing.
Thanks to anthropogenic effects, the hellbender is also in serious decline. One study held over the course of twenty years observed a 77% decline in hellbender populations (Wheeler et al, 2003).
So, what is causing such a sharp downturn for the lowly ‘lasagna lizard’? Unfortunately, like most of the declining populations that we see in ecosystems today, the ‘Allegheny alligator’ suffers from an acute case of humans. We’ve screwed up their habitats pretty badly.
The hellbender conducts gas exchange completely through their skin. As a result, they require oxygen-rich, shallow, fast-flowing streams for their habitats. Because of their strict habitat requirements, hellbenders are extremely sensitive to environmental changes. One of the biggest contributors to the ‘devil dog’s’ decline is siltation of their habitat via roadways, agriculture runoffs, pollution, and damming of waterways (Unger et al, 2017). All of these things muddy up their native stream systems. This reduces oxygen availability in the environment and can smother the animals.
Hellbenders aren’t prolific breeders, either. A relatively long-lived species, hellbenders have slow growth and developmental rates and an extremely low number of offspring live long enough to join the breeding population (only around 1% in the wild). With their recruitment rates practically crawling along and full-grown adults dying thanks to damaged habitat, things aren’t looking good for the lowly ‘ground puppy’. It isn’t hard to see how their population numbers dropped so drastically
But it isn’t all over yet. Hellbenders have been getting a helping hand recently thanks to joint efforts from state agencies, zoos, and university research. Captive breeding programs and scouting areas for appropriate habitats alongside PR campaigns for public support (Mullendore et al, 2014) have helped the hellbender slowly make a comeback.
Check out this video by the Toledo Zoo to learn more about conservation efforts for these guys:
- Mullendore N, Mase AS, Mulvaney K, Perry-Hill R, Reimer A, Behbehani L, Williams RN, Prokopy LS. Conserving the eastern hellbender salamander. Human Dimensions of Wildlife. 2014 Mar 4;19(2):166-78.
- Wheeler BA, Prosen E, Mathis A, Wilkinson RF. Population declines of a long-lived salamander: a 20+-year study of hellbenders, Cryptobranchus alleganiensis. Biological Conservation. 2003 Jan 1;109(1):151-6.
- Unger SD, Williams LA, Groves JD, Lawson CR, Humphries WJ. Anthropogenic Associated Mortality in the Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis). Southeastern naturalist. 2017 Jun;16(2).
- Toledo Zoo (2014)
*Nicknames provided by the US Fish and Wildlife Service: https://www.fws.gov/southeast/wildlife/amphibians/eastern-hellbender/