Long-toed Salamander
The Long-toed Salamander (Ambystoma macrodactylum) is one of two salamander species found in Alberta, both belonging to the Family Ambystomatidae, the mole salamanders. The Long-toed Salamander overlaps very little in distribution with the other salamander species in Alberta, the Tiger Salamander, which reaches its western range limit along the foothills of the Front Range of the Rocky Mountains.
The Long-toed Salamander is currently on the 'Yellow B List' in Alberta, meaning that the species is not at risk but attention should be given to potential limiting factors.
The Long-toed Salamander is found in habitats ranging from temperate rain forests to semiarid sagebrush deserts and alpine meadows. This species does not seem to be part of the amphibian assemblage typical of the climax forests in the mountains of Oregon and Washington. This, together with its wide habitat range, suggests that the Long-toed Salamander may be a fugitive species, preferentially exploiting disturbed or marginal habitats rather than climax situations, at least in the western part of its range.
In Alberta, most Long-toed Salamanders are found in the Cordilleran
Natural Region, made up of the Montane and Subalpine Ecoregions. This area is characterized as having a generally short summer with pronounced precipitation, and a climatically variable winter. A significant number of Long-toed Salamanders are also found in the Boreal
Natural Region consisting of the Lower Boreal-Cordilleran, Upper Boreal Cordilleran, and Low Boreal Mixedwood Ecoregions. This area typically has low annual precipitation, with short summers and long cold winters. A few Long-toed Salamander populations are also found on the margins of the Fescue Grass Ecoregion.
The Long-toed Salamander requires both aquatic habitat for breeding and terrestrial habitat. Breeding habitat in Alberta consists of lakes or ponds. Breeding lakes are often large and shallow, with boggy edges and abundant aquatic vegetation. Deep lakes with little aquatic vegetation are also used when adjoining wetlands can provide the necessary shelter and shallow areas for egg-laying. Long-toed Salamander larvae are generally not found in ponds with predatory fish such as Rainbow Trout, however there are documented exceptions. A survey of lakes over a wide range of altitudes in the Cascade Mountains found that larval salamander densities were significantly lower in lakes with fish than in lakes without fish and that coexistence seems to depend upon a spatially complex habitat.
Ponds used as breeding habitat can be either natural or man-made and are usually shallow without an abundance of aquatic vegetation.
The vegetation surrounding breeding ponds and the terrestrial habitat used by adult
Long-toed Salamanders in the Fescue Grass Ecoregion is the rough fescue, Parry oat grass association which occurs in wet areas and along forested riparian river valley. In the Montane Ecoregion, the habitat occupied by the Long-toed Salamander is the closed-canopy Lodgepole Pine and Douglas fir association; Balsam Poplar and willow tend to predominate in wet areas. Because the majority of Alberta's Long-toed Salamanders are found in this ecoregion, these vegetation associations are most closely correlated with the presence of the species in the province. Long-toed Salamanders have also been found on heavily modified agricultural land.
A terrestrial habitat use study conducted on the Long-toed Salamander in west-central Alberta near Hinton determined that individuals were found primarily in well-drained areas with a thick litter layer on the forest floor and close to relatively permanent water bodies. Factors such as tree canopy cover and downed woody debris, which are important habitat attributes to many other salamander species, were not associated with the abundance of Long-toed Salamanders in this area. Terrestrial Long-toed Salamanders were abundant in seral (successional) stages ranging from three-year old clearcuts to 180-year-old forests. In addition, breeding population size (based on egg counts) was not associated with the area of clearcuts within 250 m or 500 m of the breeding ponds. These findings show that robust populations of Long-toed Salamanders can occur even with active logging in the area.
Almost all Long-toed Salamander localities in Alberta are situated on surficial deposits of a fluvial, aeolian, glaciofluvial, or lacustrine nature. It is likely that a highly permeable substrate is necessary to maintain the high soil moisture required by terrestrial salamanders, and to recharge the temporary and permanent waterbodies used as breeding habitat. Terrestrial Long-toed Salamanders appear to be primarily fossorial in Alberta, and a substrate featuring abundant interstitial spaces is necessary for a salamander with such weak burrowing abilities. Restriction of populations to valley bottoms in montane areas is thus to be expected, as the combination of permeable fluvial or glaciofluvial substrate with high water potential produces abundant terrestrial and breeding habitat in these areas.
The Long-toed Salamander moves from upland areas to its aquatic breeding habitat as soon as the spring melt occurs. The primary stimulus for breeding in the Bow Corridor population appears to be the thawing of the ground. The number of adult salamanders at the breeding ponds in the Bow Corridor increased with both temperature and precipitation, indicating that movement and emergence are encouraged by these factors.
Adult salamanders can be active in and around breeding ponds at temperatures as low as 4ºC. Males arrive first at the ponds to await the females. Males stay in breeding ponds an average of 28 days whereas females stay for an average of 18 days.
Terrestrial Long-toed Salamanders, including sexually mature and immature individuals, spend most of their time below ground, often in small mammal burrows.
Little information is available on the overwintering habits of the Long-toed Salamander. Groups of eight to 14 (mostly adult) salamanders were found together, buried 50 to 70 cm below the surface in loose gravel. Each group was near large spruce trees in low, well-wooded areas with relatively high soil moisture and where snow cover remained until the spring. Temperatures at the overwintering site never dropped below 2
degrees Celsius.
Long-toed Salamanders are noted for movements of breeding adults to and from breeding habitat and movements of new metamorphs from natal ponds to terrestrial habitat. Mass movements of breeding adults and emerging metamorphs have been observed.
Home ranges of terrestrial adult and juvenile Long-toed Salamanders in the Bow Corridor were determined by locating salamanders that had been implanted with radioactive tags. The mean estimated home range sizes for females, males and juveniles were 115.6 ml, 167.5 ml and 281.6 ml, respectively. These are large home-range areas for a species that spends most of its time underground.