Amphibians of the Stikine area

Alaska is not home to many reptiles, according to Joshua Ream, cultural anthropologist with the Alaska Herpetological Society. Alaska is home to some marine turtles, as well as garter snakes, but not much else.

On the other hand, he said, the state is home to a variety of amphibians. From 2010 to 2018, Ream has researched the kinds of amphibians that can be found in Southeast Alaska, particularly around the Stikine River. There has not been much research into Alaskan amphibians, he said, so much of this work was to help establish baseline data for future projects.

"We don't know a lot about the amphibians that exist in Alaska, very basic data about what species, and how many, and what their range is, is still unknown in most parts of the state," Ream said. "We don't have a lot of long term data to know whether or not populations are changing over time, so this is one of the first long term programs of monitoring amphibians."

For a quick biology lesson, amphibians are cold blooded vertebrates that are similar to reptiles, but have several key differences. Amphibians lack scales, for example, and several species are capable of breathing through their skin. They often undergo metamorphosis from aquatic larva into air-breathing adults. Frogs are a very common example of amphibians.

For his research, Ream, fellow researchers, and local volunteers had three main search areas. They researched the Stikine River itself, Wrangell Island, and Mitkof Island. There are five types of amphibians that call this area home, he said: The Columbia Spotted Frog, the Wood Frog, the Boreal Toad, the Long-toed Salamander and the Rough-skinned Newt.

Ream said that there was supposedly a sixth breed of Salamander in Alaska, the Northwestern Salamander, that was first reported in the 1990s. However, he said that they did not find any in all of their research, and there have been no reported sightings of the Northwestern Salamander in the area before or since that initial report. It might have just been a mis-reported Long-toed Salamander, Ream hypothesized, which is a close cousin of the Northwestern Salamander.

During their research, according to Ream's presentation, there were a total of 2,555 specimens found and documented. This includes individual animals, but also clumps of tadpoles or eggs, he said. The large majority of them were found in various locations around the Stikine River, he said, but this may be due to the fact that was where they spent most of their time looking.

There were 71 specimens located on Wrangell Island, another 29 on Mitkof Island, and 25 more found in various places outside of the three research zones. Compared to the other amphibians in Ream's presentation, the Rough-skinned Newt is very common on Wrangell Island. There were 61 specimens of this salamander found in Wrangell, as well as 10 specimens of the Boreal Toad. Ream said they did not find any other species in Wrangell, though Columbia Spotted Frogs have been reported in the area.

Mitkof Island was home to a more diverse array of amphibians, research showed. There were 15 Rough-skinned Newts, 11 Columbia Spotted Frogs, and one Boreal Toad. Ream said that there were two additional frogs located on Mitkof. Due to them escaping before close examination, they were labelled as "Rana spp.", which he said means that their genus is known, but not their species.

Ream pointed out that there were several factors that could potentially limit or skew the research. Some factors include limited funding and limited timespans allowed at some research spots, he said. The weather was also a big factor. Ream also said that there is always human error and people could just be tired or not pay attention and miss an amphibian.

Ream explained that having baseline data about amphibians is important because they typically have "boom" and "bust" cycles with their populations. Without a long term set of data, however, it would be difficult to tell if something is happening to a population of amphibians outside of the norm. Should a species of amphibians suddenly start to disappear outside of the normal cycle, he said, it could be a good indicator that there is a wider problem with the ecosystem in that area.

"Amphibians are also great indicators of biological health," he said. "So when something starts to affect the environment, especially water quality contaminants, it usually affects amphibians first."

Ream said that the research will be published in the next edition of the scientific journal "Northwestern Naturalist," which he said will be coming out within the next six months.

 

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