Interesting factoid from a 1948 PhD thesis

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jonathan
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Interesting factoid from a 1948 PhD thesis

Post by jonathan »

In a thesis that characterized the herps of Benton County, the author wrote about Clouded Salamanders:
This is the most easily found of the plethodon salamanders, and occurs in relatively large numbers within restricted areas of the proper habitat.
and later
Of at least 200 specimens of Aneides ferreus that I have seen in the course of this study
At least 200 clouded salis in just one county! The entire naherp.com database only has 26 records of the species across its entire range. How did this guy find so many?
The large logs and the large stump are fire charred on the exterior, whereas the smaller stumps are not, but are the remnants of lumbering operations. The age of this set of conditions is not known, but the large logs are much older than the lumbered stumps. The fire-charred exterior of these logs apparently plays a large part in maintaining a certain ideal condition within the log. This exterior is very hard, and sheds most of the rain falling upon it, but on the other hand keeps down evaporation and drying during the summer months. Furthermore, this surface is quite resistant to insect workings and its rigidity helps to hold the softer inner wood in position. The net result is a habitat that is moist but not soggy or wet in the winter and one that remains moist, at least inwardly, during the summer.

When one tears into such a log, the heart wood is found to be decayed to the point where it can be torn out easily with the proper instrument, but yet is firm enough to retain its shape without crumbling. This inner wood will be found to be riddled with cracks and tunnels, and will support a tremendously varied invertebrate fauna. It is supposed that certain of the invertebrates produce the tunnels in the wood, but there is some evidence (see under food habits) that the Aneides may at least enlarge these. Whatever animal produces them, these tunnels are utilized by the salamanders to reach even the innermost sections of the logs. From one of these logs, on March 19, 1942, at least 25 Aneides of all sizes were collected in less than an hour. This log measured approximately 4 feet in diameter by 12 feet in length, and only a small proportion of it was torn away. In another log (approximately 4 feet by 28 feet), in this same locality, 21 Aneides, and 2 clusters of the eggs of this species were taken on July 7, 1946. To collect these, only about 10 feet of the length of the log was torn into along its southern exposure.
Okay, should be pointed out that ripping apart habitat is a bad idea nowadays with the extremely limited amount of such habitat available anymore. In many places it is completely illegal. Still, those densities are incredible. The author stated that over 90% of the Clouded Salamanders he saw were found in "open grass or bracken areas within or at the edge of fir forest, containing fire-charred or partl decayed fir logs and/or fir stumps." So why don't we find so many Cloudeds today? Is it that we just aren't ripping apart stumps, or is the problem that 4' diameter fir stumps aren't lying around the ground in the frequencies that they used to 65+ years ago?

I should note that he did find 25 cloudeds under surface cover, but most of those were found on very wet days under surface cover near the same old-fir-logs-and-stumps situation.
Richard F. Hoyer
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Re: Interesting factoid from a 1948 PhD thesis

Post by Richard F. Hoyer »

Jonathan:
Are you referring to the thesis by Dr. Robert M. Storm? I believe Doc Storm earned his PhD in 1998. As an undergrad in Wildlife Science at OSU, Dr. Storm taught Ornithology, Mammalogy, Genetics, and Evolution to all major in Fisheries and Wildlife. I also took an elective 2 credit course in Herpetology form Doc. Storm. He is now in his 90's and live in south Corvallis.

At any rate, when I wished to gather up a some herp samples including Clouded Salamanders, I would go to the community of Kings Valley. At the north end of that community is an long defunct lumber mill. There were decaying wood left here and here and under such decomposing wood piles I would encounter a number of Clouded Salamanders.

The area is in the Luckimute River valley floor and not up in the woods so to speak. It is basically grassland / brush habitat.

Richard F. Hoyer
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jonathan
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Re: Interesting factoid from a 1948 PhD thesis

Post by jonathan »

Yes, it was Dr. Storm! That's a great coincidence.

What you say about the defunct lumber mill is fascinating. I assume you know that Wandering Salamanders are found on Vancouver Island, Canada, despite not occurring in Oregon or Washington. The leading theory is that they were introduced there by the hide tanning industry, which shipped huge amounts of tan oak up from northern California to Vancouver Island, from the exact California coastal regions whose genetics match the Vancouver salamanders. I wouldn't be surprised if those salis that you found were also lumber-introduced transplants and not native to that particular locale.
Richard F. Hoyer
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Re: Interesting factoid from a 1948 PhD thesis

Post by Richard F. Hoyer »

Jonathan:
Having my major focus on the Rubber Boa and the two species of Contia, I do not have much of a handle on life history and distribution of the various species of amphibians. But it seems to me that the surrounding forested habitat in the Kings Valley region would likely be suitable for the presence of the clouded salamander.

But you could very well be correct that the presence of the species at that particular site was due to specimens hitching a ride and getting translocated.

Richard F. Hoyer
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