Species Endangered (MS-Blog Series from) XII / 09

Gastric-brooding Frog

Class: Amphibia

Order: Anura

Latin name: Rheobatrachus silus / R. Vitellinus

Range: (Australia) - Inhabited a limited ranges at eastern Queensland.

IUCN: EX (CR) / EX (CR)¹, CITES: -/- (not checked)

(a 2009 situation)

Sometimes word of the day, frogs are more important than people usually realize. Them are – like echoed also by us in our earlier amphibian post – supposed most threatened from the animal orders, not the least by the climatic change, etc. But, as they also are often mentioned having been first species that moved from seas to the land, one easily presumes them most 'primitive' of the terrestrial animals. In fact that appears false assumption, for we learn that their extant main groups (Frogs, Salamanders, and limbless Caecilians) actually are timed roughly for the same periods as the modern reptiles. Oldest from reptiles still extant genera, turtles and crocodiles therefore appear slightly more distant from evolutionary origins than current amphibians families, it seems. (However, also appears stated that earliest amphibians were around some 300+ Million years in the past, already). In spite of how exciting these preceding view-points might be, our interest in this (brief) text is delimited for the variety of colourful amphibian species. Since the rain forest species are not only most numerous but most impressive from looks (as well most threatened of them, also often said), this consists largely from representing them.

So, the above frog(s) examples for this part, are not selecte from the reason of being extinct – actually they represent only singular species among several mentioned in this text. Nevertheless, and like we find mentioned, the Rheobatrachus (genus of frogs) contained above mentioned two species (R. Silus/.Vitellinus), both rather exceptional. Mentioned as gastric-brooding frogs from the reason that in both the reproduction was by female frog ingesting it's (fertilized) eggs, which then developed for juveniles in the frogs stomach (and were finally vomited as juveniles from it's mouth). Unique manner even among the frogs which show multitudes of variety and peculiar examples at their reproduction. In our only marginal acquaintance from the life of the frogs, this makes us almost to think the truth often being stranger than fiction.

Anyway, sad part of course is that no Gastric-brooding frog seems been found after their rapid disappearance during brief period in begins of 1980s (Been only known for science since about 1972/3). At that time the reasons and causes for frog extinctions in general weren't yet too clearly understood, and so, in lack of any especial knowledge from the species we're not focusing on that here more precisely. However, at the amphibian declines generally, an increased vulnerability of the small frog populations is nowadays often mentioned. Most alarming prospect, equally often noticed, is their habitat fragmentation(/destruction), like mentioned in following paragraphs:

"Shrinking Habitats. Pressure generated by the world's expanding human population creates an insatiable demand for land that results in the destruction of the natural habitat of plants and animals. This process is offset, to a very small degree, by the creation of natural reserves, but these can become prisons rather than havens for animals such as amphibians. Many amphibians live in small, local populations, the longterm survival of which depends on the occasional immigration of animals from other such populations elsewhere. Increasingly, amphibians are being forced to live in fragmented landscapes within roads, built-up land, and agriculture separating one population from another. There is growing evidence that this isolation leads to an inbreeding and a consequent loss of genetic diversity, decreased survival rates and an increased incidence of anatomical deformities.”(Halliday-Adler 2002, p. 32-33)

As well is said: “Although amphibian population declines have attracted a great deal of scientific and media interest, there is no reason to think they are unusual or unique. All the factors that adversely impact upon amphibians pose a threat to other forms of wildlife. [...]"(Halliday-Adler 2002, ibid.) ...Remarks at the book then continue with mentioning the disappearance in freshwater habitats noticeably having impaired the amphibians populations for some time (other wildlife as well). Also, fx how the protected areas should be designed to create optimal conditions in nature reserves is stated being increasingly important, since the populations based on single limited area are more likely to face eventual extinction, sometimes despite protection. As well appears noticed, that for smaller part/some level the diminished habitat can be replaced by habitat creation - like the underpasses and tunnels built in some places to create amphibians some safety from roadkills, fx on routes for their breeding sites (ao efforts at their protection mentioned). (Halliday-Adler, p. 33-35) Remembering that (in cases) populations of thousands individual frogs have been noticed rapidly vanished (as result of increased vulnerability to variety of threat), also gives some importance for the above mentioned.

The amphibian decline in overall presented at our earlier post, we'll leave that for these few words and the following text mostly serves the purpose of presenting examples from variety in the amphibian lifes. But, fx the Amphibia web's pages about the global decline contain some further information, probably (also seems contain the downloadable Amphibian Action Conservation Plan). And for the interested, from various threatened amphibian around world, EDGE's Amphibian top 100 list presents many, any of those less usually or not commonly noticed. (And – further more - not forgetting to mention this word on behalf the amphibians ; we also learns from it about another exciting frog species, the Phantasmal poison frog (EN), whose skin secretions contain some particular compounds, possibly found of use in the human medicinery as well as aid in the research of pain-killer medicines (or something like that, sounds not at all too unsual or surprising, concerning the amphibians have especial skin formations in overall, etc) - Even though I find that least interesting from aspects presented on the text (Maybe so 'cause I don't much care from the medicines markets and labs, and even less from the prospective views of the global medical businesses or firms. Nevertheless, despite my slight antipation, it's sometimes mentioned that penicillin probably has been one of the most benefiting inventions in the preceding century - for human kind.)

...But for to stay on our main topic in this; following paragraphs are focused on colourful and exciting characteristics of the amphibians. Many of the species mentioned in the following, I suppose, are from the better known colourful and sometimes also the most usually represented examples. In spite of that, there's a lot especial and interesting in them to familialirize with (So I noticed when writing this...).

Often in the nature, bright colour serves purposes of aposematism (ie as warning sign to potential predators from species being distasteful/of it's toxic defenses). Some frogs also exhibit polymorphic appearance (different colour patterns found even in the individuals of same species). From this, again the most popular examples are to be found in the small toxic frogs of South American forests (Presented in the pic above), that appear in variety of species (there's at least three separate genera of these tiny frogs with toxic defenses). Variability in the skin colour and pattern also more generally appears typical to amphibians, as well as does the sexual dimorphism; In several cases male and female frogs exhibit rather different looks, fx. Further more, some are mentioned changing their overall skin color according to body temperatures – not quite same manner or as impressively as the chameleons, but some fx change their tones of color according the surrounding environment or frogs mood (like mentioned from the European leaf frog, Hyla arborea (LC) - also, when exposed to sunlight it appears paler by color.)

Colour patterns appear as method to warn their would-be-predators, but it's also found commonly used as camouflage by the frogs - to avoid detection from potential prey. Most frogs are carnivores - about majority eat insects but larger species also various other prey and fx typically the diet of some rain forest frogs ranges from worms and little snakes to even small mammalians (like bats, fx). To hide from their prey, certain species are found having adopted/imitating the usual background colors, even to level their skins reflecting smaller variations of litter and leaves found on the forest ground. Some horned frog species most typically mentioned examples from such adaptations. (Another interesting example, ao, we find presented in the pocket guide from East African frogs [2006]; in form of (Tanzanian) reed frog species (Hyperolius Orkarri), whose overside colours are mentioned closely matching the granite rock environment it lives at – Acc. book species is only known from few areas).

From the use of colour as warning from species palatability, there's also plenty examples at the Salamander (Caudata) families (Perhaps, not so evident of the species in pic above, Golden-striped Salamander, Chioglossa Lusitania, VU) - Salamanders and Newts form a parallel group for Frogs and Toads, the Newts being (in general) more accustomed to watery environments and Salamanders usually more terrestrial, except during their breeding periods. They typically are impressive from appearance and colour; An european species most renown of them, Fire Salamander (Salamandra salamandra, LC) represents very bright yellow colours. It has also interestingly given reasons for many odd beliefs in the past. According to the most usual from these, it was in the Middle Ages widely asserted capable of setting up fires by its sole presence and also (was believed) resistant to flames. According to another often mentioned anecdote, this false belief was already widespread and common during the Antique; Even to the level that Pliny the elder (23-79 A.D.) experimented it's accuracy when preparing his renown book, Naturalis Historia; - by throwing the fire salamander into flames, with expectable result of course. As noticed, that apparently didn't prevent the same false belief to persist through centuries for hundreds years afterwards.(...the underline on this added 28.08.2015) (Serves well also to show how a mistaken belief and fallacy can remain, and in time become part of the shared common consciousnes.)

But, from the real qualities of the Fire Salamander, it's fx mentioned that a lot variation appears between coloration of the individual animals. Some are almost completely yellowish, some represent only small bright dots. Many other salamanders as well represent by bright color a warning from their toxic defences (even though that doesn't completely prevent them being predated) – however, I've not checked if that the case also in genus plethodontidae, salamanders that are mostly renown from breathing only through their skin since they do lack the lungs completely. As for other interesting salamander characteristics, it is mentioned that some species - like the N. American Eastern newt (LC)(Pic below from Eastern Newt in the eft phase, adults are mentioned differing from color) - can find their routes from several kilometers distance for the watery streams and ponds they've been taken far away from. Even more, it's mentioned that they are able to use the position of the sun, with the aid of sensing polarized light to perceiving their position and using that (information) for directioning. As well mentioned, it been demostrated that they are able to detect Earths magnetic field and use that to form some kind of 'maps' from the surrounding environments - having sort of "GPS-system" of their own; ie it is noticed suggesting that the Newts nervous system maybe able to develop and store some detailed information from their living regions. (Halliday-Adler book, on p. 52). (How precisely/how well that mechanism is understood/studied, I've not checked, but there's a few researches from the subject listed at the end of this post). Actually, various animals similarly use some kind of 'compass' to make their routes and journeys, most renown are the migrating birds. Salamanders, whose plentiful families are distributed around the most continents (excluding the Africa and Australia), appear likewise threatened as the other amphibians by varying degree – 3 species are listed critically endangered, at least (Halliday Adler, p. 56-59).

Next we briefly devote also few words for other amphibian typical features, mainly on the diversity in their reproducing. First, there's this exceptional case in point in form of the South-American mouth-brooding frogs. In their case (the male) frog carries small tadpoles/froglets in it's vocal pouch, also providing nutrition them, and from where the fully developed little frogs then emerge.(Halliday-Adler, p 27-28). Mouth-brooding frogs include at least the species we find presented with the name Rhinoderma darwinii (VU) - listed so from it's observed decline in part of range, though mentioned still rather common on some places (acc. its IUCN Red list data sheet on Rhinoderma darwinii). Most frogs, however, do reproduce by their more common manner, laying amounts of eggs on water sources (which usually are fertilized externally). Especially the rain forest species, however, have developed additional strategies to their breeding and protection of the juvenile.

A manner used by many from tree frogs is to deposit eggs on vegetation/leafs overhanging the water, (also typical to the reed frogs, a group in the African arboreal frogs with over 120 species)(Spawls-Howell-Drewes 2006, p 184). The eggs later drop for the water where the tadpoles then start their metamorphose (for a frog). There's also species whose eggs are developed in certain 'foam-nests'. When the edges of the nest dry it falls for waters below. The inner in the foam nest remains moist some days, allowing the tadpoles to emerge in it. In some cases the creation of the foam nests involves lot group-behavior by frogs, the foam released by female frog(s) and forming the nest between leaves, which is then 'hardened' from it's outer surface by several male frogs hangin' on beside nest's edges.

Further more, there's as well many that use some alternative method like depositing them eggs in the burrows dug near the edges of the seasonal (water) pools - after the rainwater floods for pools and finally enters burrows, tadpoles swim for the open water.

(Like in the exemplary case from (East-)African Guinea Snout-burrower, interesting looking species from genus we find provided with the name hemisotidae, mentioned at Spawls-Howell-Drewes (2006) book). (Species pic above)

Somewhat more especial, may appear the reproduction of some of the earlier mentioned tiny (S. American) Poison dart frogs (from genus Dendrobates), species that live mostly within the leaf litter on level of the rain forest floor. Fx, in the case of some of the Strawberry poison frogs (D. Pumilio, LC), the frog first lays its eggs on leaves and carries the hatched tadpoles (under the protective foil on frogs back) to the axils of certain plants, or, to cloaks of trees in some cases. These contain small level of water in which the tadpoles grow to small froglets (number of other species also live in these aquatic micro-environments). The female frog also feeds tadpoles with the unfertilized eggs. Some Madagascar frogs are mentioned with somewhat resembling manner at their reproduction and 'parental care'.(Halliday-Adler 2002, p 28-29) Yet, further another exceptional method (in the variety of frog breeding) is maintained by some another South-American species that we find presented as 'Marsupial frogs', or Rana marsupial (Gastrotheca ovifera, EN). In that case eggs are first directly fertilized and each is placed to a certain protective 'pouch' on females back, where they remain in moist and pretty safe until emerging as fully developed froglets from there - and the juveniles when 'born' seem to bop directly from the frogs back. The species also is mentioned endangered acc. it's IUCN listing (IUCN Red List data sheet; Gastrotheca ovifera). Various other frog species carry their fertilized eggs on the adults back (/or, fx attached beside frogs legs like the Midwife-toads). Most usually the developed tadpoles are just dropped for water to develop. (I guess this variety of frog breeding methods only presented by brief look for the topic in above sentences... but, seems quite adequately covered, so let's leave it for that now.)

Finally, this kind of gallery of frog wonders and especial features cannot do without mentioning the 'flying frogs'; A species group comprising from the Asian (arboreal) forest frogs, that glide long distances (from tree to another) with particularly developed formations in limbs (webbings, spread for like parachutes/gliding surface, that 'permit the kermit' for “fly”, very seemingly) Among these we find a species provided with name Rhacophorus nigropalmatus (LC); or Wallace's flying frog after A.R. Wallace, 19^th century naturalist explorer also presented in our recent post. (The Indo-Malaysia islands Wallace journeyed contain various animals first recognized by Wallace and therefore named after him ; from the birds most renown are probably the Moluccan Megapode (Eulipoa wallacei, VU) and a paradise birds species Wallace's Standard Wing (Semioptera Wallacei). He also describes both quite thoroughly in the book.) For the flying frog(s) Wallace also devotes a few paragraphs, though far less in lenght than descriptions from the above mentioned species - But, it wouldn't feel too surprising if some frog species would also be named after him. In overall the Rhacophorus frogs belong for the Afro-Asian tree frogs, and in addition to this example mentioned genus/group contains number of other glider frogs. Recognized as separate species only later, perhaps. (Pic below; Wallace's flying frog)

But, for now we'll have to cut this in brief, since this only was meant to present some ordinary examples from that variety and overwhelming richness of life - From the amphibians in their about 6300 recognized species in existence worldwide and some even mix together and/or are not clearly differentiated from near similar/co-species. Many of them vulnerable to various threats, Climatic Changes the most often mentioned of those. Anyone can also easily search further details from the mentioned few species we were able to present in this (and from various other; fx, nothing we were having time or space to present from the vocal communications of the frogs, or about some other things - like from the species especially adapted for watery environments/lifes; the leaps and bounds of the frogs; not much anything from most of the popular families – like the arboreal tree frogs of the Central-/South Americas noticeable from them slender and curious looks, and most often presented in the natural books pics...And whatever else has recently been researched from amphibians and their evolutionary histories, obviously.)

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Note:

1. Species also presented with the CR listing, since both seems been moved to the category/status of EX rather recently. (In the IUCN fact sheets listed as extinct about the turn of the century. But, what a happy surprise it would make if some surviving specimen/individuals still would turn out to be found, somewhere, even that it seems very unlike possibility.)

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Sources/other information:

La Marca - Manzanilla 2004. Gastrotheca ovifera. In: IUCN 2009. IUCN Red List of Threatened Species. [Version 2009.2.] <www.iucnredlist.org>. Downloaded on 19 November 2009.

Ed Meyer (et al) 2004. Rheobatrachus silus. In: IUCN 2009. IUCN Red List of Threatened Species.[Version 2009.2.] <www.iucnredlist.org>. Downloaded on 19 November 2009.

Jean-Marc Hero (et al) 2004. Rheobatrachus vitellinus. In: IUCN 2009. IUCN Red List of Threatened Species. [Version 2009.2.] <www.iucnredlist.org>. Downloaded on 19 November 2009.

Carmen Ubeda (et al) Rhinoderma darwinii. In: IUCN 2009. IUCN Red List of Threatened Species. [Version 2009.2.] <www.iucnredlist.org>. Downloaded on 21 November 2009.

Halliday, T. -Adler, K., (2002), The New encyclopedia of Reptiles and Amphibians. N.Y.

Spawls-Howell-Drewes, (2006), Pocket guide to the Reptiles and Amphibians of East Africa. London.

Magnetoreception at (some) amphibians;

(Both studies from The Journal of Experimental Biology)

Brassart, J [et al], 1999, Ferromagnetic material in the eastern red-spotted newt Notophthalmus viridescens., (JEB) Vol 202, Issue 22 3155-3160

Phillips, John B. [et al], [2002] `Fixed-axis' magnetic orientation by an amphibian: non-shoreward-directed compass orientation, misdirected homing or positioning a magnetite-based map detector in a consistent alignment relative to the magnetic field? , (JEB) 205, 3903-3914

[ Pics at the text from Halliday-Adler book; except the Guinea-Snout burrower from Spawls-Howell-Drewes.]

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Species Endangered (MS-Blog Series from) - II / 09

Yellow-Bellied Toad

• Class: Amphibian
• Order: Anura
• Latin name: Bombina Variegata
• Range: From Central-/Eastern Europe to Mediterranean region
• IUCN Status: LC (Least Concern) / Cites: Not listed
  

(Above classifications are a 2008 situation).

Yellow-bellied Toad (Bombina variegata) is quite widespread, small-sized toad (a distinction between toad and frog is a minor but interesting one: in general toads are more accustomed to land-life, they fx usually have shorter legs and drier skin. The differences are not significant and as a term frog practically includes also toads. Therefore, not a clear taxonomic separation exists/is reasonable to make) Toads like frogs also habitat, at least for their breeding behavior, small ponds and lakes, as well as other watery places.

Yellow-bellied Toads are found mostly in foothills and mountain-sides. It can be spotted from coniferous and mixed forests, grasslands, meadows, etc, in the higher altitudes, from deciduous forests in low elevations. The diet includes most typically small terrestrial insects (but also fx small spiders, crustaceans and various aquatic insects). It hunts them by night. The bombinatoridae family are also often mentioned noticeable from their voices, which remind the sound of small clocks clacking merely than more typical frog croaks - one who has heard such 'concerto' on the late walk fx, may perhaps understand/recognize the species especial voices from this description. These toads are easily confused with their 'sister-species' Fire-Bellied Toads (Bombina bombina). Outer distinction in between species is only possible to make of small details, main one being the color in their belly-side (which is believed to serve as warning for the predators as a threatened toad may turn around upwards to show its colorful belly as a sign of being toxic/poisonous). The two parallel (sub-)species also hybridize in many their contact areas.

In contrast to various other amphibian species, Yellow-Bellied Toad is not considered particularly demanding by habitat and even tolerates some wetlands highly polluted by humans. It can also be found on urban forest parks. Since frogs in general are freshwater dependable species, their existence in the water sources often tells from the good condition of waters. Actually, as urbanization and human settlements in Europe are often dense, frogs are in places also dependable from artificial aquatic habitat. Sometimes they are found using for their breeding small wells close to urban housings (but in many places over their range, the replacement of those traditional human water use sources by newer methods is also noticed as one reason in the amphibian disappearance). Both species (-variegata/-bombina) in general are relatively common, the one in question here having a range from Mediterranean Europe to the central and eastern parts of the continent. But, the ongoing population trend in both cases is in decline.

In the strictest sense of endangerment it perhaps would not qualify for this series (from endangered species), as it is only counted LC in the IUCN list and not disappearing so fast as would mean the classification of seriously threatened. But, fx subspecies Apennine Yellow-bellied Toad (Bombina pachypus), found only in Italy is listed as endangered(EN) because of its fast decline. Further, including Bombina variegata here becomes more justified if examining the situation of amphibians in whole. Findings of the European Red List of Amphibians¹ give some hint about the scope of overall decline: in addition to about 15 or more severely endangered - including critically endangered Karpathos Frog(Pelophylax cerigensis) and Montseny Brook Newt(Caloritron arnoldi) - more than half (59 per cent) of the (European) amphibian species populations were in decline and only 36 per cent found in stable state. Main significant threats found (for the amphibians) are; 1^st -Habitat loss (mankind caused loss of natural habitat and suitable living area), 2^nd -Pollution (including causes related to climate change), 3^rd -Invasive alien species (and some hazardous diseases that affect frogs particularly, such as Chytridiomycosis) (p. 11-13 in that IUCN survey mentioned – see the note before). Looks like hard times for frogs, since their general disappearance and declining populations has already been seen happening for some decades, at least.

The disease mentioned in above chapter, chytridiomycosis is relatively recent mysterious killer of amphibian species, and still remains somewhat so. It's origins are according to some studies traceable to certain African frog-species, that was widely transported around the world and therefore seems as most potential vector in diseases spread to several continents. Though, chytridiomycosis has also been shown having existed in amphibian populations some decades, possibly latent. It has supposedly only become virulent in the more recent times. The disease most dramatically affects to amphibian decline in cooler conditions/zones (under 28 C, it is said), but it's also shown having had impact (as co-effect of Climate Change) in the regional amphibian extinctions seen since 1980s. The warming and more unstable/ambient climate may significantly hasten the spread of chytridiomycosis, noticed afterwards in some cases where dramatic population decline had happened.
More conventional and typical reasons for amphibian decline are human caused habitat destruction and urbanization; major ones also include the drying of wet-lands, road construction, water pollution. In addition to those comes the increased land cultivation and agriculturalism, but there's yet several other factors and in general decline is mostly seen a result from various reasons (as often summarised in final conclusive sentences). But, one also finds, among the most significant reasons there is also the overall increase of toxins and use of chemical contaminants(pesticides and some fertilizers, – particularly concerning the amphibians has been the Atrazine, herbicide used about since 1950s, although its more recently been banned in European Union) ; Another, probably more recent, but also mentioned as threat is the raises in UV-B Radiation ; And there's yet more conventional/regular reasons, like the animals being collected for food, pets, etc.

From amount of about over 6300 amphibians species only 85 are endemic to Europe (most numerously there habitating the moisture Mediterranean region where expected drying will cause the largest changes). If enlarging the scope to get the correct picture, that worldwide decline, precisely said, threatens about 30 per cent of their populations - And therefore more seriously than any other animal (order); birds or mammals fx. However, no single most reason is possible to raise aforth as most responsible for that.

But, there's of course plenty of reasons to say (much of) the above mentioned is related to global warming. Some frog populations, restricted to limited range or other ways particularly vulnerable, have in cases been found completely disappeared/extinct in their area. That so, even when inhabitating the protected, conservation habitat - Like that most renown 'iconic Climate Change victim'; the Golden Toad (Bufo periglenes). But, same climatic changes in the region did as well simultaneously cause the disappearance of several other frog populations. Similar losses elsewhere in the world (fx US and Australia) have also been possible to connect in the impacts of general drying. A seemingly small ecologic changes can have a big effects, sometimes; fx according to one research² a slight reduction in the water amount in shallow ponds (from about 50 cm deep to only 20 cm deep) increased the dead-rate from 12 to 80 per cent in the amphibian tadpoles (downright reason for deaths was found from another typical amphibian disease, Saprolgenia ferax³).

For the positive side, most of the amphibians and frogs reproduce by laying multitude of eggs, and can therefore often be successfully increased in captivity. In nature most eggs and/or tadpoles die until mature age, but in the artificial human supervised conditions their great potential for reproductivity can be improved remarkably. Therefore, captive-breeding has sometimes saved threatened species from total extinction and can be used efficiently to return them for the natural wild habitat. A popular example of such, Mallorcan Midwife Toad (Alytes Muletensis) (VU) - now often mentioned as example of living fossil, because it was at first only known from the fossil remains - is a species that was supposed have gone extinct in earlier times, mostly because the early human settlement (in roman times, 2000 years ago) also introduced predators like viper snakes and competitive frogs to the island. Luckily, remains of the small population were found at remote mountains around 1980s. Since that, the toads were increased in protection, new populations from them subsequently later established for suitable areas where mentioned invasive alien species don't reach (in the mountain region of island). Also, it is counted as one of the two European endemic amphibian species that still were on the raise in population numbers, as mentioned in the earlier refered European Red List of Amphibians. (Also, there's pics/some more about the species fx at Arkive.)

Thinking optimistically, resembling that aforementioned newly discovered case, there is still also even new species found, especially in the more biodiversity rich areas like rainforests. But these are of course merely singular examples. Also, as supportive program to improve the amphibian survival, captive-breeding often is mainly a supplementary/last chance protection (in addition to other actions that would be needed in the first place.) In most cases it is always also somewhat risky, fx because there's a possibility from spread of diseases for the wild populations.

So, on the basis discussed things, our example here Bombina Variegata (Yellow-bellied Toad) fits more than adequately to present here in our series from endangered species. Even though it is a common species and not in immediate danger of extinction, seems quite plausible that future seems to hold plenty of things that could cause it becoming so. Wikipedian heading from the decline in the class/taxa also points out a fact not yet mentioned: due that amphibians have two-part life-stages(ie in brief are generally dependable from both aquatic and terrestrial conditions in during life-cycles), they are more vulnerable to human caused changes for world's biodiversity than some other animals. Whatever the most potential reason, globally alarming thing is the extinction rate, according to conservative estimates about 200 times the past rate(if compared to overall amphibians background extinctions from the past).

But, since we don't want end this post in too depressive comments, we'll finally here also remind ourselves that the amphibians have a long evolutionary history, far longer than man. And, as mentioned before, their reproductivity potential gives yet some reasons to optimism also. As well, there's also much not yet known from them; fx frogs are mentioned returning to the same places(ponds, fx) for breeding each year, which is some kind of mystery too, exact reasons unknown, if not for the frogs themselves - Only that one hopes those ponds to remain there in the future still...

Notes:

1. Temple, H.J. And Cox, N.A. 2009, European Red List of Amphibians. Luxembourg. Office for Official Publications of the European Communities. – The report available from: http://www.iucn.org/about/work/programmes/species/?3204/Europes-amphibians-and-reptiles-under-threat--- → under downloads/European Red List of Amphibians (pdf). (A studies carried by IUCN for European Commission)

2. Pounds, A.J. , 2001. Climate Change and Amphibian Declines. Nature 410; 639-40. [Cited via: Flannery, Tim, 2005. The Weather Makers. The history and Future Impact of Climate Change.]

3. Or, the diseases name may be a synomous to Chytrodimycosis(?), since its also fungus-related and Flannery mentions it as one cause in the annihilation of frog species around the world. Whatever the case, a quick search from Wikipedia didn't give us any direct answer/clarification to that important terminological question...Possibly, the term is such a new one, that it's not in any common use yet(?)... (The free Dictionary by Farlex returns us a definition from Saprolegnia Ferax (not from Saprolgenia Ferax): "A fungus that attacks living fish and tadpoles and spawn causing white fungus disease: a coating of white hyphae on especially peripheral parts (as fins)" (though, as the results from the study mentioned seem to date as far as 2001, and probably more recent research has surfaced since then, but those search results, especially the terms absence of directories and definitions, seem just...unlikely. [?])

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