• TIMING OF MAJOR LIFE HISTORY EVENTS
• PREFERRED HABITAT
• COVER REQUIREMENTS
• FOOD HABITS
• PREDATORS
• MANAGEMENT CONSIDERATIONS

TIMING OF MAJOR LIFE HISTORY EVENTS:

Migration to breeding waters begins in winter for southerly subspecies and during spring snowmelt for northerly subspecies. Sustained temperatures above freezing and abundant, free soil water apparently trigger migration. Migration almost always occurs at night. Long-toed salamanders in cold climates crawl on top of and beneath snow to reach breeding ponds; the ponds are often still partially frozen during mating [2,5,12]. Mating behaviors are described in Anderson [1]. In all locales, males arrive at ponds before females and generally stay for longer periods of time. Females leave soon after depositing their eggs [2,5,12]. They attach eggs to vegetation, submerged wood, or rocks. Santa Cruz long-toed salamanders lay single eggs; southern long-toed salamanders lay eggs in small clusters. Other subspecies tend to lay eggs in masses [2]. The breeding period lasts about a month [2,5,12]; high-elevation populations generally have longer breeding periods than low-elevation populations [12].

Life span: A sampling of adults and subadults (individuals that have metamorphosed but not yet reached sexual maturity) in a northern long-toed salamander population in Alberta showed an age distribution from 1 year to 10 years of age, with most individuals in the 2- to 3-year-old age bracket [20].

Life History - General: Life histories of long-toed salamanders vary with temperature and moisture conditions. Several life history patterns are evident: a one-season larval period (in warm climates); either a short facultative one-season larval period or a two-season larval period (moderate climates); and a three- to four-season larval period (cold climates). In warm climates, period of development is limited by precipitation. Breeding cannot take place until temporary ponds fill. Variation in rainfall determines the length of time water remains and, therefore, period of larval development. Metamorphosis occurs when ponds begin to shrink [2]. In cold climates, development time extends to several years due to short growing season. Regardless of subspecies, long-toed salamander larvae do not transform until attaining a snout-to-vent length of at least 33 mm. In cold climates, it may take 4 years to reach that size [12].

Life History of Subspecies:

Eastern long-toed salamanders - In ponderosa pine forest near Moscow, Idaho, migration to breeding ponds began in late February. By late April, most adults had left the ponds [22]. Howard and Wallace [13] reported that low-elevation (1,390 feet (420 m)) populations in Nez Perce County, Idaho, bred in early February; mid-elevation (3,760 feet (1140 m)) populations in Baker County, Oregon, bred in April; and high-elevation (8,150 feet (2470 m)) populations in Wallowa County, Oregon, bred in June and July. Females at high-elevation sites laid fewer, larger eggs than females at lower-elevation sites. Number of eggs per female averaged 166 (SD +/- 60) at the 1,390-foot site and 90 (SD +/-49) at the 8,150-foot site. Larvae from populations below 6,930 feet (2100 m) metamorphosed in their first summer, while larvae from higher elevations metamorphosed in late summer of their third or fourth year.

Northern long-toed salamanders - A sample of wild individuals in Alberta reached sexual maturity at 47 mm in length, a length attained at about 3 years of age. Well-fed, captive individuals, raised in aquaria from eggs, exceeded 47 mm in length by their first year but did not reach sexual maturity until their second year [20].

Southern long-toed salamanders - Populations in the Sierra Nevada have facultative one-season and two-season larval periods. In Calaveras County, California, at 6,530 feet (1980 m) elevation, time from egg deposition to metamorphosis was 80 to 90 days in temporary ponds. Larval period is probably longer at that elevation in large, permanent ponds. At higher elevations, southern long-toed salamanders do not reach the critical size for metamorphosis in a single season. In Alpine County, California, (elevation 8,085 feet (2450 m)), mating and egg deposition occurs from late May to late June, as soon as ponds partially thaw. Larvae develop in summer and spend the winter beneath ice, transforming in August or September of their second year. Adults first reproduce at age 2 or 3 [2].

Santa Cruz long-toed salamanders - Living in a mediterranean climate, Santa Cruz long-toed salamanders experience one of the driest environments of the species. Larval development is completed within one season. In drought years, rainfall is sometimes insufficient to allow normal breeding and larval development to occur. In wetter years, migration to breeding ponds begins with late fall and winter rains. Santa Cruz long-toed salamanders only migrate on rainy nights. Subadults move to ponds after light rains, but adults migrate only after heavy, ground-soaking rains. Breeding occurs from January to mid-February and eggs hatch from late February to mid-March. Time from breeding to larval transformation and pond shrinkage varies from about 90 to 140 days. Santa Cruz long-toed salamanders are sexually mature at age 2 [2].

PREFERRED HABITAT:

General: Long-toed salamanders occur in diverse habitats including coniferous forest, oak (Quercus spp.) woodland, alpine, sagebrush (Artemisia spp.), and marshland communities [2,26]. They use springs, ponds, small lakes, slow-moving streams, and marshlands for breeding and larval development [2,5].

Habitat of Subspecies:

Eastern long-toed salamanders occur in ponderosa pine, lodgepole pine, and subalpine fir-Engelmann spruce (Abies lasiocarpa-Picea engelmannii) zones. A population near Moscow, Idaho, used artificial ponds within ponderosa pine-grand fir (A. grandis) forest for breeding [22]. Eastern long-toed salamanders have also been documented in wheatfields (Triticum aestivus) with irrigation ponds, ponderosa pine-big sagebrush (Artemisia tridentata) woodlands with temporary ponds, and sparsely vegetated whitebark pine-mountain heather (Pinus albicaulis-Phyllodoce empetriformis) communities with permanent lakes [12,13]. Long-toed salamander larvae, presumably eastern long-toed salamanders, were found in a spring within a cottonwood-quaking aspen (Populus spp.-P. tremuloides) riparian community on the Bruneau Resource Area of southern Idaho [18].

The southern long-toed salamander occurs in mixed Sierra Nevada coniferous forest and alpine communities. It has been noted at 8,075 feet (2,750 m) elevation in Alpine County, California. A population at 6,534 feet (1980 m) elevation in Calaveras County, California, occurred in and near a temporary pond formed from snowmelt. The pond was shaded by large trees, including white fir (Abies concolor), ponderosa pine (Pinus ponderosa), lodgepole pine (P. contorta), and quaking aspen, that provided shade for most of the day. The pond was clear and moderately acidic (pH 5.9). It lacked aquatic vegetation and was littered with needles and small woody debris. Further east, a population occurring at 8,085 feet (2,450 m) in Alpine County, California, occupied permanent ponds fed by snowmelt and springs. Lodgepole pine, western white pine (Pinus monticola), and mountain hemlock (Tsuga mertensiana) were sparse to numerous around pond margins but always provided at least some shade. The pond waters were very clear, lacking live vegetation but with considerable downed woody debris including floating and submerged logs [2].

Santa Cruz long-toed salamanders in the two Santa Cruz County populations occur in and near temporary ponds in coast live oak (Quercus agrifolia) woodlands [2,21]. Pond waters are often turbid and aquatic plant growth is extensive. In summer, adults seek moist areas such as seeps and willow (Salix spp.) thickets near pond shores [2]. The Monterey County population occurs in a cattail-bulrush (Typha-Scirpus spp.) marsh [26].

COVER REQUIREMENTS:

Since they are highly susceptible to desiccation, adult and subadult long-toed salamanders spend most of their lives underground or beneath objects. Larvae use submerged objects and aquatic vegetation for cover [2].

Southern long-toed salamander larvae generally remain hidden under bark, logs, or other submerged objects. They overwinter beneath such objects, in water more than 12 inches (30 cm) deep. In mid-summer in Calaveras County, California, subadults sought cover beneath objects in dried temporary ponds; they were never found outside pond perimeters. In late summer, subadults were still beneath objects in the dried ponds but had formed ball-shaped aggregations of 15 to 43 individuals. Adults used large, rotting logs for cover most of the year [2].

Santa Cruz long-toed salamander larvae in Santa Cruz County use dense aquatic vegetation and turbid water for cover. Subadults cannot disperse to coast live oak woodlands immediately after transformation due to arid summer climate. After summer metamorphosis, they retreat to willow thickets at shore edges or beneath matted vegetation or other debris at the bottoms of drying ponds. When these substrates dry, subadults seek the same substrates used by adults in summer: rodent burrows, buried logs, dense tule (Scirpus acutus) mats, or other microhabitats where moisture is retained throughout the dry season. Subadults often aggregate at these sites, tightly entwined in groups of three to nine individuals. With onset of autumn rains, subadults move into coast live oak woodlands [2]. Adult Santa Cruz salamanders in Monterey County have been found in willow thickets and beneath wooden boxes and other urban debris during the dry season [26].

FOOD HABITS:

Adult long-toed salamanders hunt terrestrial and aquatic arthropods. They also scavenge dead arthropods [19,30]. The diet of larvae is similar: larvae consume aquatic arthropods and terrestrial arthropods that fall into the water, and scavenge arthropod remains. In addition, some long-toed salamander larvae are cannibalistic. Cannibal larvae are morphologically different from "normal" larvae, having larger heads and jaws, reduced gills, and a more slender body. Larvae may become cannibalistic in response to either high larval population density or a scarcity of other food sources [31].

In summer, proteins and fats are stored in the tails of long-toed salamanders. These nutrients are metabolized during long periods of dormancy [32].

Eastern long-toed salamander larvae in Oregon have been observed feeding on hatchling Pacific treefrog (Hyla regilla) larvae. Cascades frog (Rana cascadae) larvae and fairy shrimp (Anostraca) were other potential prey in the breeding pond [31].

PREDATORS:

Adult long-toed salamanders are probably not highly vulnerable to predation. Except during migration, they are secretive in habit. Even then, they migrate to and from breeding ponds at night, in winter or during spring snowmelt, when most predators that would potentially prey on long-toed salamander are relatively inactive [5]. Additionally, long-toed salamanders secrete a toxin from glands in their tails when captured; the toxin often prompts predators to drop and abandon the long-toed salamanders [32].

Near Moscow, Idaho, a common garter snake (Thamnophis sirtalis) was observed in the process of swallowing an eastern long-toed salamander. Other potential predators captured near breeding ponds were western terrestrial garter snakes (T. elgans) and shrews (Sorex spp.). However, these predators were not active until late April, when all but a few male long-toed salamanders had already departed from breeding ponds and returned to forest cover [5].

Long-toed salamander larvae prey upon each other [2,5].

MANAGEMENT CONSIDERATIONS:

No entry

Related categories for SPECIES: Ambystoma macrodactylum | Long-Toed Salamander