Woody and arboreal habitats of the Green Salamander (Aneides aeneus) in the Blue Ridge Mountains

Abstract

The green salamander (Aneides aeneus) is primarily considered a rock crevice dwelling species. However, many early observations from Kentucky, Tennessee, Virginia, and West Virginia report A. aeneus taken from woody and arboreal habitats. There have been only four published records of A. aeneus using such habitats within the Blue Ridge Disjunct population of southwest North Carolina, northeast Georgia, and northwest South Carolina, and no records since 1952. Here I report two personal observations of A. aeneus using arboreal habitats in North Carolina. Additionally, I report nine observations, made by others, of A. aeneus using woody, arboreal, or otherwise non-rock-crevice habitats in North and South Carolina, including the first non-rock-crevice A. aeneus nesting record for the Blue Ridge. I also speculate that woody and arboreal habitats play a much larger role in the life-history of A. aeneus than generally thought, and that the rarity of A. aeneus is linked to the loss of American Chestnut and old-growth forests. INTRODUCTION AND METHODS The green salamander (Aneides aeneus) is distributed from central Alabama to southwestern Pennsylvania along the Appalachian Plateau (Petranka, 1998). A separate and smaller cluster of populations, the “Blue Ridge Disjunct”, occurs in the mountains of southwest North Carolina, northeast Georgia, and northwest South Carolina (Bruce, 1968; Petranka, 1998). The green salamander is the only representative of the genus Aneides, or “Climbing Salamanders”, in the eastern United States and is generally uncommon across its range due to specialized habitat requirements (Petranka, 1998). Aneides aeneus is almost exclusively observed inhabiting rock crevices of outcrops, which are located within associations of the mixed-mesophytic forest (Gordon, 1952; Corser, 1991; Petranka, 1998). However, early observations from Kentucky, Tennessee, Virginia, and West Virginia report A. aeneus breeding and foraging within woody and arboreal habitats (Gordon, 1952). Pope (1928) and Barbour (1949) report A. aeneus being taken almost exclusively from beneath the exfoliating bark of standing or fallen, yet “solid”, dead trees, mostly American Chestnut (Castanea dentata). Fowler (1947) reports A. aeneus being found under the bark of a fallen American Chestnut tree. Barbour (1949) reports one A. aeneus within the cavity of a standing dead American Chestnut and a brooding female beneath the bark of a fallen tree. Pope (1928) reports one individual within a rotted log and a brooding female within the small cavity of a prostrate limb of an Oak (Quercus spp.) tree. Welter and Barbour (1940) and Canterbury (1991) also report observations of A. aeneus beneath the loose bark of dead trees or within rotted stumps. In contrast with these widespread observations of the use of arboreal habitats and woody debris by A. aeneus in the main range populations, there are only four published records of A. aeneus individuals observed in habitats other than rock crevices in the Blue Ridge Disjunct. Three of these observations were adjacent to, or near, rock outcrops. Bishop (1928) reported an individual A. aeneus observed beneath a piece of bark lying on the surface of a rock several feet above the ground in Tallulah Gorge, Rabun Co., GA. Brimley (1941) reported a single A. aeneus found within a woodpile on August 1,1938 in Highlands, Macon Co., NC. Gordon (1952) reported that this woodpile observation was within 100 feet of a rock outcrop colony of A. aeneus. Gordon (1952) reports an immature A. aeneus individual crawling down a dead oak (Quercus spp.) sapling leaning against a rock outcrop along Clear Creek in Rabun Co., GA. Brimley (1927) and Swartz (1954) report an individual A. aeneus taken by J.O. Pepper on August 3,1926 from the “surface of up-standing tree at about 3 1⁄2 ft up, in damp woods” at Pinnacle Mountain, Pickens Co., South Carolina. While the four non-rock-crevice records are of individuals, A. aeneus nests are known only from rock crevices in the Blue Ridge Disjunct (Snyder, 1971). Here I report two personal observations of Aneides aeneus using arboreal habitats in North Carolina. Additionally, I report nine observations, made by others, of A. aeneus using woody, arboreal, or otherwise non-rockcrevice habitats in North and South Carolina, including the first non-rock-crevice A. aeneus nesting record for the Blue Ridge Disjunct. Observational descriptions, provided by others, were collected by contacting professional biologists and amateur naturalists familiar with A. aeneus populations in the region. Unless otherwise cited, the following information is summarized from personal communications provided by the observers. FIELD OBSERVATIONS OF ANEIDES NON-ROCK-CREVICE HABITAT USE IN THE BLUE RIDGE DISJUNCT The following two observations were made at Biscuit Rock, Highlands, Macon Co, North Carolina, USA, at ca.1,219 m elevation (35°03’N, 82°11’W). On 6 June 2003, at 1900hrs, during a light rain, with the aid of a high power flashlight, I observed an individual A. aeneus in a horizontal position at the bottom of a small, vertical, crevice-like tree cavity (2cm x 37cm), 42cm vertical distance above the ground, and located within a live Rosebay Rhododendron, Rhododendron maximum. The diameter of the trunk was 11 cm at the height of the crevice. On 7 June 2003, at 12:20 hrs, during a heavy rain, with the aid of a high power flashlight, I again observed another individual A. aeneus in a horizontal position at the bottom of a small tree cavity (2cm x 4cm), 72cm vertical distance above the ground, and located within a separate, live Rosebay Rhododendron, R. maximum, approximately 2m from the 6 June 2003 observation. The diameter of the trunk was 8cm at the height of the crevice. Because the trunk of the shrub was slanted, the actual trunk distance the salamander had to travel to reach the crevice from the ground was 97cm. In both observations, the salamanders were small, appeared to be less than one year of age, and retreated further into the cavity upon illumination. Both cavities were apparently created when a horizontal limb detached from the main trunk. Both shrubs were attached to a rock outcrop known to contain a rock-crevice dwelling population of A. aeneus. The following three observations were located in Cedar Mountain, Transylvania Co., North Carolina, USA, at ca. 900m elevation (35°08’N, 82°41’W). The nearest suitable rock outcrop habitat, referred to as “Sherwood Forest Cave”, is >750m from the observations and is know to contain a population of A. aeneus (Wilson, 2001). On September 1974, upon splitting a downed American Chestnut log, Castanea dentata, Herbert Ball discovered an adult female A. aeneus tending a clutch of nine+ eggs (Millie Blaha, pers. com.). The brooding female was photographed by the late George and Millie Blaha (Figure 1) and the following descriptions are approximated, by the author, from their photographs. The log was about 25cm in diameter and contained a hollowed chamber about 6cm in diameter. The clutch contained at least nine eggs suspended from the sides of the chamber. At least four hatchlings were produced within two weeks of the initial discovery (Millie Blaha, pers. com.). A color photograph was deposited in the N.C. State Museum of Natural Sciences by the author (ALB 10409, Figure 1). On 24 October 1993, Beth and Speed Rogers discovered two A. aeneus individuals under a clay terra cotta dish resting upon a rotting Black Oak (Quercus velutina) stump. The two salamanders were photographed and documented by Mille Blaha (Figure 2). The stump was approximately 40cm in diameter, 75cm high (measured in the field by the author, May 2000), and was cut seven years prior to the observation (Millie Blaha, pers. com.). The two salamanders were about 7.5cm total length (approximated, by author, from photographs). Upon disturbance, the pair crawled down the side of the stump and into a crevice at the base of the stump. A color photograph was deposited in the N.C. State Museum of Natural Sciences by the author (ALB 10410, Figure 2). During the spring of 2000, Speed Rogers, amateur naturalist, found one large A. aeneus climbing on his wooden deck, approximately 4.5m above the ground (Speed Rogers, pers. com.). The following four observations were made at the Falling Creek Camp, Tuxedo, Henderson Co., North Carolina, USA, at ca 790m elevation (35°11’N, 82°28’W). The nearest suitable rock outcrop habitat, known as “Falling Creek Camp”, is >500m from the observations and is known to contain a population of A. aeneus (Wilson, 2001). Beginning in June, 1991, and repeatedly throughout the summer, Joe Duckett, resident camp naturalist, observed an individual A. aeneus living within the entrance of a small tree cavity (2.5cm × 5cm), approximately 1.5m above the ground (approximated, by author, from photographs), and located within a live standing Scarlet Oak (Quercus coccinea). The salamander was feeding on small insects that were attracted to a black sap oozing out of the cavity. The salamander was no longer found after late summer. Identification was confirmed, and the habitat was photographed, by Allen Boynton, non-game wildlife biologist, North Carolina Wildlife Resources Commission, during the summer of 1991. In May, 1997, upon submerging a decorative driftwood log into a fish aquarium, Joe Duckett observed an A. aeneus escape from within an approximately 10 cm wide hollow within the log. The driftwood log had previously been left outside on a porch. During May, 1999, Joe Duckett again repeatedly observed an individual A. aeneus living in a cavity of a standing, yet dead, tree throughout the summer approximately 10m from the 1991 observation. The cavity entrance was 7.5 cm × 15 cm and located 1.8m above the ground (measured in the field by the author, May 2001). The salamander was no longer found after late summer. During the summer of 1999, Joe Duckett, along with a young camper, observed