Montana Field Guide

EGGS
Typically laid in ponds in small clusters of 9-81 (X = 23, SD = 14.5, N = 36 across 5 sites in northwest Montana). Each ovum is black or brown above, white to gray below, and surrounded by two jelly layers. Ovum diameters are approximately 2.5 mm (0.1 in), but total egg diameters, including the two jelly layers, are usually 12-17 mm (0.47-0.67 in) (Slater 1936).

LARVAE
Translucent, light tan, or black dorsally and laterally with black and gold flecks. White to
pinkish ventrally. Three pairs of external feathery gills emanate from the sides of the head with 9-13 gill rakers on their anterior surface (Russell and Bauer 2000). Snout-vent length (SVL) of 10-60 mm (0.4-2.4 in).

JUVENILES AND ADULTS
Fourth toe on the hind foot is elongate and longer than the sole of the foot. Incomplete or fully formed yellow, orangish, or reddish dorsal stripe may extend from the tip of the snout to the tip of the tail. Eyelids are the same color as the dorsal stripe. White flecking present on the lateral and ventral surfaces over a black lateral and pink ventral base color. 12-13 costal grooves are present. SVL of 25-80 mm (1-3.1 in) (Russell et al. 1996).

Adult Coeur d’Alene Salamanders (Plethodon idahoensis) have nasolabial grooves and their toes are webbed and shorter than the soles of their feet. See sections on habitat use for differences in habitat used by Long-toed and Coeur d’Alene Salamanders. Western Tiger Salamander (Ambystoma mavortium) eggs have 3 jelly layers and have total diameters less than 10 mm (0.4 in), including the jelly layers. Larval Western Tiger Salamanders have larger heads are usually olive green to silvery white in base color and have 15-25 gill rakers on the anterior surface of their gills (Russell and Bauer 2000). See sections on distribution for geographic areas of possible overlap for Long-toed and Western Tiger Salamanders.

Although individual animals tend to use the same migration routes, no preference in habitat, relative soil moisture or vegetation is evident for the species’ movements to and from breeding pools (Beneski et al. 1986).

Adults are found in a wide variety of habitats including semi-arid sagebrush, alpine meadows, dry woodlands, humid forests, rocky shores of mountain lakes, and disturbed agricultural areas (Nussbaum et al. 1983). Outside of the breeding season adults are primarily subterranean and have been documented to commonly move at least 600 m (1,969 ft) from the nearest breeding site on the University of Montana’s Lubrecht Experimental Forest (Maxell et al. 2009). During the breeding season adults may be found in shallow waters or under logs, rocks, and other debris near water.

Larvae and adults feed on a variety of aquatic and terrestrial invertebrates and larvae feed on other amphibian larvae including conspecifics (Farner 1947, Anderson 1968b, Walls et al. 1993, Maxell et al. 2009). Franz (1997) identified that larvae diets consisted of ostracods/cyclops; also red water mites, insect egg masses, algae. Farner (1947) determined adult diets contained terrestrial arthropods (mostly formicid coleop, diptera) 74% and aquatic insect larvae (mostly trichop) 37%.

Adults go to the breeding ponds immediately after snowmelt. In the Pacific Northwest and western Montana, it is the earliest amphibian to breed (Nussbaum et al. 1983). Breeding takes place in temporary or permanent ponds or in quiet water at the edge of lakes and streams, usually those without fish present (Funk and Dunlap 1999, Monello and Wright 1999). Like all salamanders, they have internal fertilization. Following breeding, they move to adjacent uplands.

Eggs are attached to vegetation or loose on the bottom at depths up to 0.8 m (31.5 in) and hatch in 3 to 6 weeks. Paedogenesis is unknown in this species. Larvae usually transform at the end of their first summer at low elevations or at the end of their second, third or fourth summer at high elevations and in cold waters at lower elevations (Howard and Wallace 1985, Maxell et al. 2009).

In Idaho, they have been documented breeding in February to May below 2,100 m (6,890 ft) and June to July above 2,100 m (6,890 ft). Clutch sizes are typically around 167 at lower elevations and 90 at high elevations. Metamorphose below 2,100 m (6,890 ft) occurs when SVL is 35-40 mm (1.4-1.6 in) in year 1 and above 2,100 m (6,890 ft), during year 2 to 4 when SVL 47 mm (1.9 in) (Howard and Wallace 1985). Metamorphs are typically seen in August to September (Brunson and Demaree 1951, Franz 1971). Salamanders become sexually mature when SVL is 50 mm (2.0 in).

The following is taken from the Status and Conservation section for the Long-toed Salamander account in Maxell et al. 2009

Long-toed Salamanders are the most widely distributed and common amphibian species west of the Continental Divide with larvae being found in most fishless standing waterbodies with adjacent soils that provide suitable terrestrial habitat (i.e., sites that are not surrounded by extensive areas of bare rock). Their status in the front ranges east of the Continental Divide is uncertain. Risk factors relevant to the viability of populations of this species are likely to include all the general risk factors described above with the exception of harvest and commerce. Individual studies that specifically identify risk factors or other issues relevant to the conservation of Long-toed Salamanders include the following. (1) A number of studies have found adverse impacts of introduced fish on Long-toed Salamanders. Funk and Dunlap (1999) found that trout effectively excluded salamander populations from lakes in the Bitterroot Mountains. However, when fish went extinct in lakes that did not have spawning habitat salamanders were able to recolonize some of them over a twenty-year time period. In the Palouse region of northern Idaho, Monello and Wright (1999) found the presence of Long-toed Salamanders to be highly negatively correlated with the presence of a variety of fish species, including Largemouth Bass (Micropterus salmoides), Bluegill (Lepomis macrochirus), Channel Catfish (Ictalurus punctatus), and Goldfish. Tyler et al. (1998a) found a similar pattern in North Cascades National Park and found that nitrogen levels were positively correlated with salamander densities in fishless lakes, apparently an indication of bottom up limitations on the food web. Similarly, Long-toed Salamanders in the central and northern portion of the Sierra Nevada Mountains are largely restricted to fishless lakes (Bradford and Gordon 1992 as cited in Knapp 1996). Tyler et al. (1998b) found that when Rainbow Trout (Oncorhynchus mykiss) were stocked in experimental ponds with Long-toed Salamanders, larval survivorship was lower and larval body lengths were smaller than in control ponds without fish, supporting the theory that introduced trout not only impact salamanders through direct predation, but also indirectly by increasing refuge use and, thereby, reducing foraging time. (2) In a study of the Long-toed Salamander in Douglas-fir (Pseudotsuga menziesii) forests in the Swan River Valley, McGraw (1997) found that areas where overstory removal (250-300 trees harvested per hectare) and new forestry (leave 13-25 dominant tree species per hectare and retain all snags and hardwoods) harvest techniques were applied had less ground cover, higher soil temperatures, and 75% fewer terrestrial salamanders than control plots. Interestingly, he also found that larvae were more abundant in ponds where a fraction of the pond margin was harvested than either ponds whose margins were completely harvested or ponds whose forest margins were completely intact. (3) Tallmon et al. (2000) found that gene flow among populations in the Bitterroot Mountains is greater between populations on the same mountain ridge than between populations on adjacent mountain ridges, indicating that drainages between ridges act as more of a barrier to dispersal than the steep terrain on the ridge itself. The dominance of terrestrial dispersal is also supported by the genetic analyses of Howard and Wallace (1981). (4) Fukumoto and Herrero (1998) documented mortality of a minimum of 1-2% of the adult breeding population as they crossed a roadway to the breeding site in Waterton Lakes National Park in Alberta. However, the authors suggest that actual mortality may have been considerably higher, contributing to the unusual 3:1 female biased sex ratio observed at the breeding site. (5) Blaustein et al. (1994d) found that the species has low levels of photolyase, an enzyme that repairs UV-B radiation damage to DNA. Blaustein et al. (1997) subsequently found that only 14.5% of embryos exposed to 94% of ambient UV-B radiation survived to hatching as compared to 95% survival for larvae exposed to only 10% of ambient UV-B radiation. Together these findings suggest that enhanced UV-B radiation from thinning of the ozone layer may be impacting salamander populations now or will impact them at some time in the future. (6) Sessions and Ruth (1990) found that cysts of a trematode parasite apparently caused limb deformities at the site of the cyst. This parasite has now been found in larvae collected in Montana (Pieter Johnson, Claremont Mckenna College, personal communication). (7) The extent of the use of larval Long-toed Salamanders as fishing bait is unknown in Montana, however the species is known to be used in large numbers in other states (Collins 1981) so this practice does have the potential to impact populations in Montana. Accidental introduction of larvae being used for bait may result in hybridization and genetic introgression, possibly leading to the elimination of distinct genetic makeups (Collins 1981). (8) Bradford et al. (1994) found that the LC50 pH for Pacific treefrog embryos and hatchlings exposed for 7 days averaged 4.3 and that pH levels greater than or equal to 5.0 had no significant lethal or sublethal effects.