Research on Salamanders
(Research is a vital part of the activity of the naturalists in our National Parks. It is the source of knowledge about what is in the park and what is occurring. Its results furnish the supply of information which the park needs to interpret its treasures for the public. Only by continuous study of problems with full possession of facts can intelligent administration and operation of the park be achieved. The pursuit of research is a stimulus which keeps fresh and vigorous the enthusiasm of the naturalists in their lectures, guided trips afield and other efforts. – Ed.)
During the summer of 1951, Dr. Donald S. Farner and I carried out intensive field work on park amphibians and reptiles. We were ably assisted by our fellow ranger-naturalists as well as by Lawrence Bisbee of the fire suppression staff, Fred Larmie of the ranger staff, and Roy Strand of the trail crew. Lawrence Bisbee made the first big discovery of the summer by collecting a specimen of the Oregon red salamander, Ensatina eschscholtzii oregonensis (Girard), from beneath a pile of boards near Annie Spring on August 7, at an elevation of 6080 feet. This is the first specimen of this salamander to have been found in the park and it is apparently the highest altitude record for any member of its genus. Although the specimen has been allocated to oregonensis, it is actually intermediate between oregonensis and platensis (Espada), according to the recent revision of Dr. Stebbins of the University of California. A thorough search of the area in which this salamander had been collected, failed to reveal other individuals. It is possible that others will be found in the park, if looked for earlier in the season when the ground contains a greater amount of moisture.
A second important addition to the herptofauna of the park occurred on September 15 when Lawrence Bisbee, Fred Larmie and I found the northwestern salamander,Ambystoma gracile Baird, occupying bog ponds in the vicinity of Crater Spring at an altitude of 5300 feet. The three ponds in which this salamander was first found are in the rarely visited northwestern section of the park, about one-half mile south of the end of Crater Spur Motorway. Two of these ponds are small, not more than six feet in diameter, but the third is larger — about 25 feet long and 10 feet wide. Each pond is surrounded by a floating mat of vegetation and the sides drop off almost vertically to a depth of four to six feet. From these three small bodies of water, we collected nine large larvae which have a mean total length of 165 mm. These larvae, although unmetamorphosed, are sexually mature and were breeding in the larval condition. This curious situation, neoteny, is oftentimes found in this and certain other species of salamanders.
Along the northern side of Crater Creek, I found A. gracile occupying a bog pond that was almost filled with vegetation. Large larvae of this species were seen in this pond; however, my collection consists of two smaller individuals.
In the vicinity of the park, Norman Davidson and I collected A. gracile in a cut-off section of the Rogue River below Hamaker Meadows and Philip Ross and I discovered it making up part of an abundant salamander fauna in Spruce Lake, an isolated montane pond at 4750 feet in Jackson County, a mile and a half from the western boundary of the park. The lake is about 200 yards long, 30 yards wide and approaches a maximum depth of eight feet. It supports an abundant population of A. gracile, associated with the Oregon newt, Triturus g. granulosus, and the long-toed salamander, Ambystoma macrodactylum. The isolated and undisturbed nature of this body of water along with its large salamander population make it an ideal place for the study of this species. My several visits to this pond, during the first two weeks of September, revealed an A. gracile population made up of large neotenic larvae, smaller larvae of several size classes, metamorphosing larvae, and completely metamorphosed individuals.
In each of the four localities where this salamander has been collected, its globular egg masses have been conspicuous. On July 25, in the cut-off portion of the Rogue River, hatching had already taken place in some of the egg masses but in others the embryos were present in the gel. At Spruce Lake on August 31, at least 150 masses of gel were seen, hatching having taken place sometime prior to that date. On September 22, I was extremely pleased to find an egg mass of this species containing well-developed embryos in a small bog pond along the northern side of Crater Creek. Along with the various size-groups of small larvae that have been found in Spruce Lake and in the bog ponds near Crater Creek, this unhatched egg mass indicates a long egg-laying season for this species.
The salamander for which Crater Lake National Park is zoologically famous is the Mazama newt, Triturus granulosus mazemae Myers, a “water dog” that is found no place in the world except in the waters of Crater Lake. It is closely related to the common Oregon newt, Triturus granulosus granulosus (Skilton), but differs in having varying amounts of dark pigment mixed with the orange or yellow of the under surface. Dr. Farner and I were unable to find specimens of Triturus that had been collected in the park other than from the lake. We were interested in securing newts outside of the lake, but near it, in order to see if they would be ordinary granulosus or the much less common mazamae. Accordingly, the two of us were delighted to find a single large adult newt on August 25, in a cut-off oxbow along Munson Creek. We examined it carefully, finding no evidence of any of the characters which distinguish mazamae from typical granulosus, despite the fact that it had been collected only two and one-half miles from Crater Lake. Two more specimens of typical granulosus were collected September 22 in the bog pond near Crater Spring which was mentioned previously in connection with Ambystoma gracile. We believe that these collections of typical T. granulosus within the park, but outside of the lake, give strong evidence toward the idea that the Mazama newt is a subspecies entirely confined to Crater Lake.
These brief notes give an idea of progress made during 1951 in our understanding of the herptofauna of the park. For those particularly interested in this group of animals, detailed information about the amphibians and reptiles of the park has been prepared for publication sometime during the coming months.