Jackson's Climbing Salamander

Diagnosis: A large Bolitoglossa species, with females reaching 65 mm in standard length (known from only two specimens). This species has few maxillary teeth (31 in the young adult female holotype) and a moderate count of vomerine teeth (21 in the holotype). It has a simple vertebral tail autotomy mechanism (see Wake and Dresner 1967 on tail autotomy in salamanders). B. jacksoni can be distinguished from most congeners in nuclear Central America (the region from the Isthmus of Tehuantepec to the Nicaraguan Depression), B. jacksoni by tail autotomy mechanism and color pattern, a brilliant yellow with a wide mid-dorsal band of chocolate brown bordered by a thin white edge. B. jacksoni can be distinguished from Bolitoglossa species with a similar tail autotomy mechanism (such as B. flaviventris, B. mexicana, B. mulleri, B. odonnelli, B. platydactyla and B. salvinii) by virtue of having the dark coloration restricted to the mid-dorsal area (Elias 1984).Description: Females (n=2) reach up to 65 mm in standard length. Tail length of the holotype (a young adult female) is 0.8x standard length, and the tail is rounded in cross-section. Fourteen trunk vertebrae are present, along with two caudosacral vertebrae and thirty caudal vertebrae. Nostrils are small, and the female holotype had poorly developed nasolabial protuberances. The canthus rostralis is rounded and somewhat arched, and is moderately long. Eyes are slightly protuberant and are moderate-sized. Groove below eye is deep, unpigmented and does not extend to the lip. Post-orbital groove is shallow, extending posteriorly and slightly ventrally before proceeding ventrally; it then extends behind the posterior end of the lower jaw and becomes a shallow but defined nuchal groove, parallel and anterior to the gular fold. Vomerine teeth number 21 in the holotype and are found in single arching rows to either side of the midline, extending laterally to the midpoint of the choanae. Maxillary teeth are found in two rows and number 31 in the holotype. Premaxillary teeth number 5 and protrude from behind the lip. Limbs are moderately long. Three costal grooves are visible when limbs are adpressed. Both forefeet and hindfeet are fully webbed, lacking subdigital pads. Toetips are rounded when viewed from above. Relative length of fingers is 3>2>4>1; relative length of toes is 3>4>2>5>1. The phalangeal formula for the hand is 1,2,3,2 and for the hand is 2,3,3,2. Terminal phalanges of the three outermost fingers and the four outermost toes are expanded. The innermost finger and toe have pointed terminal phalanges and curve along the pad's rim towards the other digits (Elias 1984). Coloration in life: A brilliant egg-yolk yellow, with a wide dark brown mid-dorsal band edged thinly in white (with the white edging complete in the young adult female and incomplete in the older adult female specimen). In the holotype, the dark brown band originates at the level of the eyelids and runs straight across the head, spanning across the head from the center of one eyelid to the center of the other, then runs down the body, diminishing and finally vanishing just before the tail tip. In the larger female specimen, the brown mid-dorsal band is interrupted by a large, oval spot of yellow on the nape and a break on the tail; also, a brown spot is present on the otherwise yellow right hind foot. The holotype lacks ventral markings; it is not known whether the larger adult female lacked ventral markings. The eyes are metallic gold (Elias 1984).Coloration in preservative: Pale yellow ground color with broad mid-dorsal band of dark brown; the mid-dorsal brown band begins at the level of the eyelids (and spans from center to center of each eyelid), diminishing gradually toward the tail tip (Elias 1984).New Information:In October, 2017, a subadult of this species was found, photographed (see photos on AmphibiaWeb) and released. It is from a new but undisclosed locality, not far from the type locality. For a more detailed account of its rediscovery please see Synchronicity Earth's blog post on it. Only two B. jacksoni individuals have ever been collected and only one specimen was preserved, the young adult female holotype. The larger adult female was brought into captivity at the Museum of Vertebrate Zoology (MVZ) at U. C. Berkeley, where two photographs were taken, but the female either escaped or was stolen from the animal care facility within the first few days of captivity (T. Papenfuss, pers. comm.; its disappearance was not due to a deliberate release in the field by a student, as Dubois and Nemésio 2007 thought).Although one of the two AmphibiaWeb photos (of the same specimen) shows the color of the flanks as being caramel, this is due to underexposure and the color was actually a brilliant egg-yolk yellow, as in the first photograph.The species was described by Elias (1984) and the type specimen is held at the Museum of Vertebrate Zoology (MVZ 134634). It was named in honor of the collector, Jeremy L. Jackson, who accompanied Paul Elias of the MVZ on his field expedition to the Cordillera de los Cuchumatanes and the Montañas de Cuilco of western Guatemala (Elias 1984).

Endemic to western Guatemala. The type locality is in the Las Nubes sector of Finca Chiblac, roughly 12 km north-northeast of Santa Cruz Barillas, on the Caribbean escarpment of the western Sierra Cuchumatanes, Departamento Huehuetenango, Guatemala, at 1,400 m asl. Known only from the type locality and a nearby locality within 1 km away, all within Finca Chiblac. The habitat is very wet subtropical montane rainforest, receiving more than 6 meters of rainfall annually (Elias 1984).

Both individuals (a larger adult female and a young adult female) were found under the bark of felled hardwood logs in forest clearings (Elias 1984). Details of the life history are not known but like other members of the genus Bolitoglossa, this species is thought to breed by direct development (Acevedo et al. 2008).

Nothing is known about the population trend for this species. Only two individuals were initially found, and no sightings occurred its discovery in 1975 until October 2017. Both the type locality and the broader escarpment area have suffered severe deforestation due to increased agriculture and increased human settlement of refugees from the Guatemalan civil war. Until 2015, there are no protected areas near the type locality (Acevedo et al. 2008). In October 2017, Bolitoglossa jacksoni was rediscovered in the recently established Finca San Isidro Amphibian Reserve (also known as Yal Unin Yul Witz) on the northern slopes of the Sierra de los Cuchumatanes, Guatemala, very close to the original discovery site. A sub-adult found by reserve guard, Ramos Leon, is only the third specimen ever seen. The species had not be seen since September 1975, and was listed among the top 25 most wanted species in the world by Global Wildlife Conservation’s The Search for Lost Species (Mayer 2017). Bolitoglossa jacksoni is a strictly arboreal salamander whose close relatives in the subgenus Bolitoglossa range from San Luis Potosi, Mexico, to central Panama. All are arboreal and lay eggs that hatch as miniatures of adults and have no aquatic larval stage. Hence, they typically are difficult to find (Wake personal communication).

Bolitoglossa jacksoni is one of the ten "most wanted" amphibians in Conservation International's 2010 campaign to search for lost amphibian species (http://www.conservation.org/campaigns/lost_frogs/pages/search_for_lost_amphibians.aspx). Although there is no habitat left at the type locality for B. jacksoni, a second potential locality will be explored. This second locality has extant populations of two other rare salamander species (Nyctanolis pernix and Bradytriton silus) that were sympatric with B. jacksoni in 1975 at Finca Chiblac. A team will go out for a short search in mid-October 2010, led by Robin Moore of Conservation International, and a second team will conduct a more extensive search in mid-November 2010, led by Carlos Vasquez of the Museo de Historia Natural, Universidad de San Carlos de Guatemala.

Jackson's climbing salamander (Bolitoglossa jacksoni) is a species of salamander in the family Plethodontidae. It is endemic to Guatemala. Its natural habitat is subtropical or tropical moist montane forests. It is threatened by habitat loss. The salamander is among the 25 "most wanted lost" species that are the focus of Global Wildlife Conservation's "Search for Lost Species" initiative, as it had not been seen since 1975. It was rediscovered in 2017 at an amphibian reserve in the Sierra de los Cuchumatanes.