AnimalTracks.wiki

What the sources say

Pacific Giant SalamanderDicamptodon tenebrosus

Every figure, record and mechanism on the Pacific Giant Salamander profile was written from a source, and this is the working table behind it: 50 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

Profile updated

Source
01

Animal Diversity Web, University of Michigan

Dicamptodon tenebrosus (Coastal Giant Salamander). Animal Diversity Web, University of Michigan.

The page says17 cm
The source saysAdults measure 6.25 to 17 cm snout-vent length (SVL)Note: ADW's upper SVL bound, matching WDFW's 6.7 inches; the body says 'up to'.
The page saysadults weigh between 22 and 114 grams
The source saysAdult mass ranges from 22 to 114 g.
The page saysAlong the coast from northern California through Oregon and Washington into southwestern British Columbia
The source saysPacific giant salamanders occupy the coastal areas of British Colombia, Oregon, Washington, and northern California. In British Colombia, these salamanders are only found in the extreme southwest region, south of the Fraser valley and in the Chilliwack district.
The page saysfrom sea level up to about 1,830 meters
The source saysThis species can be found at elevations from sea level to 1830 m.
The page saysis mostly active at night
The source saysPacific giant salamanders are mostly nocturnal, though may be active during the early morning hours as well.
The page saysDisturbed salamanders arch their backs, sometimes thrash their tails, and let out an audible growl or bark
The source saysWhen disturbed by predators Pacific giant salamanders will emit a "bark". When approached by a predator, individuals strongly arch their bodies and may thrash their tails to threaten the predator.
The page saysadults will also head-butt and bite viciously
The source saysThe adults of this species will also head butt and bite viciously.
The page saysWeasels, river otters, water shrews and garter snakes are among its documented predators
The source saysNatural predators of Pacific giant salamanders are weasels, river otters, water shrews, garter snakes (Thamnophis genus), salmonids and conspecifics.
The page saysEggs take up to seven months to hatch into larvae about 3 centimeters long
The source saysAfter they are laid, the eggs may take up to 7 months to hatch. Larvae are 3 cm long upon hatching
The page sayswhich live off a large yolk sac for two to four months, then start hunting for themselves
The source saysand feature large yolk sacs that will sustain them for 2 to 4 months. At this point, the young are about 40 cm in length, and can begin to hunt their own prey.Note: Body drops ADW's '40 cm' figure for the young at this stage: it exceeds the species' own adult maximum (34 cm total length) and reads as a data error on ADW's dated page, so it is not repeated.
The page saysCannibalism among coastal giant salamanders is well documented in males
The source saysCannibalism is well documented among the males of the species
The page saysit may be why a female stands guard over her eggs
The source sayswhich may explain why the female is in attendance.
The page saysfor six or seven months
The source saysRange time to hatching 6 to 7 months.
The page sayscold
The source saysenvironmental conditions (such as the cold temperature of preferred streams) affect the growth and survival of the larvae
The page sayslow-silt
The source sayswith very little silt on the bottom of the stream
The page saysin rainy spells it can turn up beneath leaf litter in the moist conifer forest nearby
The source saysDuring rainy periods this species may also be found under forest litter such as leaves and small branches.
The page saysThey can also secrete a noxious substance from the tail to ward off predators
The source saysThey can also secrete a noxious substance from their tails to ward off predators.
The page saysworking through insects, amphipods, mollusks and crayfish
The source saysThey will consume insect larvae and adults, amphipods, ostracods, termatoes, mollusks, and crayfish.Note: 'termatoes' as printed on the ADW page is left out; it reads as a typo.
The page sayswith larger larvae sometimes adding fish and other salamanders to the menu
The source saysLarger larvae will prey on some salmonids, sculpins, and salamanders.
The page saysThe species hunts by sitting and waiting, then lunging a short distance
The source saysPacific giant salamanders are sit and wait predators who quickly lunge short distances in order to obtain prey.
The page sayslarge adults on land can take mice, shrews and even snakes
The source saysLarge terrestrial members of the species can handle eating small mammals such as mice and shrews or even snakes.
The page saysIn British Columbia, nearly all of them keep their external gills for life instead of completing metamorphosis
The source saysthe aquatic being neotenes which retain many larval characteristics like external gills. Neoteny seems to be more prevalent in certain, more coastal populations, specifically, British Colombia salamanders are nearly all neotenes.
The page saysEven these gilled adults sometimes move out of the stream in rainy, wet weather
The source saysThe newly metamorphosed and sometimes paedomorphic individuals move out of streams during rainy, wet periods.
The page saystakes five or six years
The source saysPacific giant salamanders exhibit slow growth rates and do not reach sexual maturity until 5 or 6 years of age.
The page saysThe species is one of its own predators
The source saysNatural predators of Pacific giant salamanders are weasels, river otters, water shrews, garter snakes (Thamnophis genus), salmonids and conspecifics.
The page saysGravel-and-boulder mountain streams and moist conifer forest from northern California to southwestern British Columbia
The source saysPacific giant salamanders occupy the coastal areas of British Colombia, Oregon, Washington, and northern California. ... The type of stream bed they prefer is composed of large gravel to small boulders
The page saysInsects, amphipods, mollusks and crayfish as larvae; mice, shrews and even snakes as large adults on land
The source saysThey will consume insect larvae and adults, amphipods, ostracods, termatoes, mollusks, and crayfish. ... Large terrestrial members of the species can handle eating small mammals such as mice and shrews or even snakes.
The page saysAn audible warning bark and a noxious tail secretion, backed up by a head-butt and a vicious bite.
The source saysWhen disturbed by predators Pacific giant salamanders will emit a "bark". ... They can also secrete a noxious substance from their tails to ward off predators. The adults of this species will also head butt and bite viciously.
The page saysYes. A disturbed one gives a bark, and it can also make a rattling or growling noise while it snaps its jaws and lashes its tail.
The source saysWhen disturbed by predators Pacific giant salamanders will emit a "bark". ... They often produce a rattling or growling sound while snapping their jaws and lashing their tail.
The page saysNo harmful effects on people are known.
The source saysThere are no known adverse effects of dicamptodon tenebrosus on humans.
The page saysA salamander facing a predator still has a full kit of defenses, from tail lashing and biting to skin secretions, plus a warning bark.
The source saysWhen approached by predators salamanders employ a variety of anti-predator adaptations. These include tail lashing, biting, arching of the back, and skin secretions. They are also known to emit a warning bark.Note: 'known to emit a warning bark' is ADW's standing statement of the behaviour, not a hedge on whether it happens; the body's bark claim quotes ADW's flat 'will emit a "bark"'.
The page saysCounted one by one, most of an adult's prey comes from the water, but by volume it eats more land animals.
The source saysAdult diets are dominated numerically by aquatic organisms but they consume a higher volume of terrestrial prey.Note: 'most ... by count' paraphrases 'dominated numerically'; 'more ... by volume' is 'a higher volume of terrestrial prey'.
The page saysBig adults foraging the forest floor on rainy nights can take mice, shrews and even snakes.
The source saysTerrestrial adults emerge from logs and other surface cover on rainy nights and forage the forest floor. ... Large terrestrial members of the species can handle eating small mammals such as mice and shrews or even snakes.
The page saysNo. Gilled adults are common in coastal populations, and in British Columbia almost every one skips metamorphosis for good.
The source saysGilled, aquatic adults are common in more coastal populations and in those of British Columbia. ... British Colombia salamanders are nearly all neotenes.
The page saysdangerLevel: Low
The source saysThere are no known adverse effects of dicamptodon tenebrosus on humans.
The page saystags: forest
The source saysDuring rainy periods this species may also be found under forest litter such as leaves and small branches.
The page saysA disturbed coastal giant salamander does the same, arching its body, sometimes thrashing its tail, and emitting a bark.
The source saysWhen disturbed by predators Pacific giant salamanders will emit a "bark". When approached by a predator, individuals strongly arch their bodies and may thrash their tails to threaten the predator.

Source
02

Washington Department of Fish and Wildlife

Pacific giant salamander (Dicamptodon tenebrosus). Washington Department of Fish and Wildlife.

The page saysNorth America's largest terrestrial salamander
The source saysThe largest terrestrial salamander in North America; adults reach lengths of 6.7 inches snout-vent length and 13.4 inches total length.
The page saysthe biggest land salamander in North America
The source saysThe largest terrestrial salamander in North America
The page says6.7 inches
The source saysadults reach lengths of 6.7 inches snout-vent length
The page says13.4 inches
The source says13.4 inches total length
The page says34 cm
The source saysadults reach lengths of 6.7 inches snout-vent length and 13.4 inches total lengthNote: 34 cm is the conversion of WDFW's flat 13.4 inches (current state agency page); ADW gives the same figure as 'may reach 34 cm'. The body says 'up to', which carries ADW's hedge as a maximum.
The page saysBy day its stream forms usually hide under rocks and woody debris
The source saysLarvae and gilled adults can be observed day or night in streams. During the day, they are typically concealed under rocks or woody debris
The page saysmountain streams
The source saysPacific giant salamanders are primarily associated with small to medium-sized mountain streams in moist coniferous forests.
The page saysmoist conifer forest
The source sayssmall to medium-sized mountain streams in moist coniferous forests
The page saysLarvae spend 18 months to two years in the stream
The source saysThe larval period is 18 to 24 months or may be permanent (gilled adults) depending on local conditions.Note: WDFW's 'may' governs only the permanent (gilled adult) alternative, which the body covers separately; ADW: 'Metamorphosis begins 18 to 24 months after hatching'.
The page saysyet they still become sexually mature
The source saysSexual maturity takes place in all forms that are around 4.5 inches snout-vent length.
The page saysmaturity comes at around 4.5 inches (11 cm) from snout to vent
The source saysSexual maturity takes place in all forms that are around 4.5 inches snout-vent length.Note: 11 cm is the conversion of WDFW's 4.5 inches (11.4 cm).
The page saysWashington's wildlife agency notes that the larval stage can be permanent, depending on local conditions.
The source saysThe larval period is 18 to 24 months or may be permanent (gilled adults) depending on local conditions.

Source
03

The IUCN Red List of Threatened Species 2022

Dicamptodon tenebrosus. The IUCN Red List of Threatened Species 2022: e.T59081A196338656.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: Category read through GBIF's copy of the Red List (iucnredlist.org refuses scripts); binomial and taxon id (59081) checked against the assessment DOI, per verify:quotes.

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.