''Salamandra atra aurorae'' is a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of the

alpine salamander The alpine salamander (''Salamandra atra'') is a black salamander that can be found in the French Alps, and through the mountainous range in Europe. It is a member of the genus ''salamandra''. Their species name, ''atra'', may be derived from the ...

''Salamandra atra'' found in south-eastern Italian Prealps. It is often called the golden alpine salamander.

Morphology

''Salamandra atra aurorae'' is very similar in body shape to all other subspecies of '' S. atra'', also in all major characters that often distinguish different

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of ''

Salamandra ''Salamandra'' is a genus of seven species of salamanders localized in central and southern Europe, Northern Africa, and western Asia. List of species References External links Salamandraat Fauna Europaea * Salamandraat Animal Diversity W ...

'': outline of the head, position of the

vomerine teeth The vomer (; lat, vomer, lit=ploughshare) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxill ...

, proportions of body parts and limbs, arrangement of glandular bulges and pores on the skin, and shape and length of the tail. However, the body surface is not entirely and uniformly black as in most other populations of '' ''S. atra''''. Conversely, the dorsal side of ''S. atra aurorae'' is broadly covered with yellow blotches and brown spots, which are broader and often coalescent on the head and the trunk, they are usually present also on the

arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...

s, the

thigh In human anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the lower limb. The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of bone ...

s and the tail, whereas they are rare on the flanks and the ventral sides. Blotches are invariantly present in all individuals, but highly variable in extent (covering from slightly more than half of the dorsal surface to almost the entire dorsal surface) and in dominant

hue In color theory, hue is one of the main properties (called Color appearance model#Color appearance parameters, color appearance parameters) of a color, defined technically in the CIECAM02 model as "the degree to which a Stimulus (physiology ...

(from pale yellow to marbled brown). The colour pattern is highly variable between individuals, without any obvious difference neither between sexes nor between sites. It is established at birth and it usually changes only slightly with growth. However, relatively rapid and extended changes from yellow to brown have been occasionally observed in captive individuals. Newly born individuals are about 50 mm long and less than 1 g, whereas adults may reach 134 mm in males and 139 mm in females, and 14 g in pregnant females. The

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

is very slight, but it has not been investigated adequately. Like in other subspecies of '' S. atra'', the

cloaca In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, a ...

l region is usually swollen in the adult males. Alps Altopiano dei Sette Comuni Bosco del Dosso

Distribution

''Salamandra atra aurorae'' lives only in the northern part of the

Sette Comuni The ( cim, Siben Komoin, italic=no, german: Sieben Gemeinden, italic=no) are seven that formed a Cimbrian enclave in the Veneto region of north-east Italy. The area is also known as the or Asiago Plateau, and it was the site of many battl ...

plateau, in the

Venetian Prealps The Venetian Prealps (''Prealpi Venete'' in Italian) are a mountain range in the south-eastern part of the Alps. They are located in Triveneto, in the north-eastern part of Italy. Geography Administratively the range is divided between the Ita ...

, NE Italy. The actual distribution is known only incompletely, because the animals are very elusive and therefore hard to detect, and adequate investigations have not been carried out. As to 2016, all documented or reliable records cluster in 12 areas, more than 0.7 km far from each other and approximately aligned West to East from Val Postesina to Monte Fossetta. However, it is unknown whether the populations detected in these areas are actually separated or instead connected through suitable intermediate areas. The estimated "area of occupancy" of ''S. atra aurorae'' is 26 km².

Habitat

Areas inhabited by ''S. atra aurorae'' are in the range 1200–1800 m and include both moderately inclined slopes and narrow valleys facing south. The substrate is rocky, calcareous and karstic. Most sites are covered with forest stands with

Beech Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...

Silver Fir Silver fir is a common name for several trees and may refer to: *''Abies alba ''Abies alba'', the European silver fir or silver fir, is a fir native to the mountains of Europe, from the Pyrenees north to Normandy, east to the Alps and the Car ...

and

Norway Spruce ''Picea abies'', the Norway spruce or European spruce, is a species of spruce native to Northern, Central and Eastern Europe. It has branchlets that typically hang downwards, and the largest cones of any spruce, 9–17 cm long. It is very close ...

, with variable abundance of leaf litter, dead wood on the ground, and patches of grass and moss. Only a few records are from shrubby meadows. In the area of the Bosco del Dosso, ''S. atra aurorae'' inhabits only the inner parts of the forest, where old-growth stands of

with

are apparently more suitable than thicker stands dominated by

. Among adults, habitat requirements are similar between males and females.

Life cycle

The life cycle of ''S. atra aurorae'' has been investigated only in part, but is probably similar to that documented for '' S. atra atra''. The

embryo An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

nic and

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

l development are completed in the

uteri The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uteru ...

of the mother and take at least two years. The juvenile is born after completing

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...

, even though it may retain small residuals of

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s for a period. Usually two juveniles are born together by a pregnant female.

Behaviour

Individuals

overwinter Overwintering is the process by which some organisms pass through or wait out the winter season, or pass through that period of the year when "winter" conditions (cold or sub-zero temperatures, ice, snow, limited food supplies) make normal activi ...

underground, most probably at some depth in the soil, where they remain inactive for at least 6 months. Since late April to mid October, instead, they still spend most part of the time resting in the soil, however often in the most upper level, sometimes concealed under occasional shelters (e.g., stones emerging from the ground, dead wood or pieces of barks on the surface). During this period, they exit and move on the surface only when the surface is wet and the air is very humid, especially after intense rains following dry periods, independently from the daily cycle of light. At difference from other '' S. atra'', ''S. atra aurorae'' does not exit regularly every day around dawn. Adult males are apparently more prone to

epigean Epigeal, epigean, epigeic and epigeous are biological terms describing an organism's activity above the soil surface. In botany, a seed is described as showing epigeal germination when the cotyledons of the germinating seed expand, throw off th ...

activity than females and juveniles. While juveniles disperse during the yearly season, adults are sedentary and remain within their

home range A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He ...

also between years. Different shelters are used by a single individual within its home range, which is a few tens of square metres on average, without any obvious differences between males and females. Individual home ranges are partially overlapping, also between individuals of the same sex. The population density has been estimated up to hundreds of individuals per hectare.

Threats, conservation status, management

All forests inhabited by ''S. atra aurorae'' are exploited for wood since centuries. However, modern practices commonly employed in wood harvesting include the use of heavy machines moving on the ground during the season of activity of the animals. In addition to causing direct mortality, they compact the soil and remove the ground vegetation along broad stripes. As a consequence, the

microhabitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

conditions become locally unsuitable for ''S. atra aurorae''. This is a critical point when considering the management of wood harvesting following the Storm Vaia, which has hit north-eastern Italy in the autumn 2018 damaging the woods where this salamander lives. Concerns have also been raised, especially in the past, for the negative impacts of the illegal and uncontrolled collection of specimens, primarily for pet trade, and for the alteration of the local microclimate as a consequence of the capture of water springs for human use. According to regional assessments following

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

criteria, ''S. atra aurorae'' has been categorized as Vulnerable (VU) under criterion D2, because the “extent of occurrence” was estimated <20 km². Instead, within the global assessment of the species '' S. atra'', evaluators proposed to rank the subspecies ''S. atra aurorae'' as Critically endangered (CR), under criterion B1ab (iii), because it was considered comprising a single local population and the habitat quality was judged as declining. The range of distribution of ''S. atra aurorae'' is mainly in the

Veneto Veneto (, ; vec, Vèneto ) or Venetia is one of the 20 regions of Italy. Its population is about five million, ranking fourth in Italy. The region's capital is Venice while the biggest city is Verona. Veneto was part of the Roman Empire unt ...

Region, specifically in the

Province of Vicenza The Province of Vicenza ( it, Provincia di Vicenza) is a province in the Veneto region in northern Italy. Its capital city is Vicenza. The province has an area of 2,722.53 km², and a total population of 865,082 (as of 2017). There are 1 ...

, but a part is in the

Province of Trento Trentino ( lld, Trentin), officially the Autonomous Province of Trento, is an autonomous province of Italy, in the country's far north. The Trentino and South Tyrol constitute the region of Trentino-Alto Adige/Südtirol, an autonomous region ...

. ''Salamandra atra aurorae'' is listed in the Annex II (originally under the name 'Salamandra salamandra aurorae') and Annex IV (under the name 'Salamandra aurorae') of the EU

Habitats Directive The Habitats Directive (more formally known as Council Directive 92/43/EEC on the Conservation of natural habitats and of wild fauna and flora) is a directive adopted by the European Community in 1992 as a response to the Berne Convention. The E ...

92/43/EEC. As a consequence, killing, handling and disturbing these animals or altering their habitat are not allowed. Scientific surveys may be carried on only after obtaining a specific permit by the Italian "Ministero dell'ambiente e della tutela del territorio e del mare". Most of the known range is included in the

Natura 2000 Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectively ...

site IT3220036 “Altopiano dei Sette Comuni”. Public awareness of the uniqueness of ''S. atra aurorae'' has recently grown in the human communities of the Altopiano dei Sette Comuni. The animal is depicted in the logo of the local natural history museum “Museo Naturalistico Didattico Patrizio Rigoni" and in the logo of the local ice hockey team “Asiago Newts Hockey”.

Taxonomy

''Salamandra atra aurorae'' had remained unknown to scientists up to 1978, when a specimen kept in a cage in a local temporary exhibition was noticed by a couple of biologists. The discovery was published for the first time in 1981. The taxonomic description and denomination appeared in the following year, first within an abstract for a congress and then in a detailed article. The subspecific name refers to Aurora, wife of the author of the description. For

nomenclatural Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. The principles of naming vary from the relatively informal conventions of everyday speech to the internationally ag ...

purposes, the type locality was designated as the “Bosco del Dosso, near Vaio di Pian del Morto, between val Remaloch and Val Rotta” and the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

has been deposited in the Zoological Museum La Specola in Florence. Since the original description, ''S. atra aurorae'' has been almost universally distinguished at the

rank, but it has been sometimes raised to the

rank. The taxonomic distinction of ''S. atra aurorae'' is corroborated by both phenotypic and genetic differences from all other populations of the '' S. atra'': all specimens of ''S. atra aurorae'' have yellow blotches covering more than half of the dorsal surface, whereas the specimens of all other subspecies are either uniformly black or at most only sparsely spotted; additionally, genetic data suggests that ''S. atra aurorae'' represents a distinct lineage within '' S. atra''. Mating between ''S. atra aurorae'' and ''S. atra'' ''atra'' has been observed under captive conditions, producing viable and fertile juveniles with narrower yellow patches.