Description
Atelopus ignescens is medium-sized toad and has uniformly black coloration on its back and flanks, with small round warts covering most of the back. The venter is wrinkled and is bright orange to red in life, becoming darker in the gular region and lighter on the belly. The ventral surfaces of the limbs are black, except for the forelimbs, which are orange-red underneath. The iris is black. In preservative, the bright underside turns to a cream color with some poorly defined black markings (Coloma et al. 2000).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Colombia, Ecuador

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (2 records).

The species has only been found in the humid forests of Imbabura, Pichincha, Cotopaxi, Napo, Chimborazo, and Bolívar provinces in the northern Andes of Ecuador between elevations of 2800-4200 meters. Habitat includes inter-Andean valleys and sub-paramo and paramo habitats between the western and eastern cordilleras of the Andes (Coloma et al. 2000).

Atelopus ignescens was previously abundant and widely distributed across its range. Studies in the 1960s, 1970s, and early 1980s found large numbers of specimens, while anecdotal evidence from as far back as 1864 also suggests great abundance. Survey evidence suggests that the species was still abundant in some localities between 1984 and 1986, but populations apparently rapidly dropped off around that time. Despite extensive searching for decades, this toad had last been seen in the wild in 1989, so the species was believed to be extinct (Ron et al. 2003). In 2016, a small population was discovered in northern Ecuador (Coloma 2016; Jaynes et al 2022) a remarkable rediscovery and showing how hard it is to declare a species extinct.

Life History, Abundance, Activity, and Special Behaviors
Atelopus ignescens is diurnal, terrestrial, and moves slowly, making it easy to locate when present (Ron et al. 2003).

Trends and Threats
It is not known what has caused the disappearance and decline of A. ignescens. The most likely cause is an outbreak of the fungal disease chytridiomycosis, which has been responsible for amphibian population declines in various parts of the world (Ron et al. 2003), and particularly among high-elevation populations of Atelopus species (La Marca et al. 2005). The first case of chytridiomycosis in Ecuador was discovered in 1980, just a few years before A. ignescens began to decline.

Habitat degradation may have contributed, as 27.1% of the paramo and 33.3% of Andean forests have been cleared in Ecuador (Ron et al. 2003). However, this species is able to withstand some degree of habitat degradation. In addition, there is little evidence of human interference in two protected areas where the species was previously found but now is not. Thus habitat degradation is probably not the main cause of this extinction (Ron et al. 2003).

Another possible cause is the presence of introduced predatory fishes, as two exotic species of salmonids have been found in streams and lakes of Ecuador’s highlands. However, this idea is not corroborated by evidence of predation. In addition, salmonids have been found within the range of A. ignescens since the 1950s, long before the toads’ decline. Furthermore, the salmonids are not found throughout the entire range of A. ignescens (Ron et al. 2003).

Another possible factor may be the dramatic increase in mean annual temperature in Ecuador in recent years. Of ninety years of climatic data analyzed in a study by Ron et al., the year 1987 saw the most extreme combination of warm and dry conditions. These conditions may have increased adult toad mortality, reduced reproductive success, or made the toad more vulnerable to attack by weakening immune function (Ron et al. 2003).

See Comment below for more recent publications.

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Habitat fragmentation
Predators (natural or introduced)
Disease
Climate change, increased UVB or increased sensitivity to it, etc.

Comments
This species was featured in news of week December 19, 2022:

Harlequin frogs (genus Atelopus) are one of the most iconic groups decimated in the amphibian decline crisis. It is difficult to know when a species is truly extinct and to study populations on the brink of extinction due to their population size and endangerment. Standalone reports of Atelopus species rediscoveries (i.e., once missing but found again) have grown substantially over the last decade, but their extent across the imperiled genus and population status’ have remained elusive in most cases. Jaynes et al. (2022) characterized Atelopus rediscoveries to investigate temporal, geographic, and genomic diversity patterns of persisting populations. They estimate that between 18 and 32 species have been rediscovered in the genus since 2002, representing 25-37% of once missing species. Rediscoveries are documented everywhere the genus occurs – spanning 100 m to > 3500 m in elevation, and geographic patterns closely matching known species abundance in each country. Genomic analysis in the geographic epicenter of Atelopus rediscoveries (Ecuador) revealed a pattern of decreased heterozygosity the longer a species was considered missing or extinct, and loss of heterozygosity over time in one species with historical comparisons. This study shows that persistence is widespread in Atelopus, but rediscovery does not equal recovery, and many species are still likely living on the brink of extinction. The Atelopus rediscovery system may serve as an important tool for understanding amphibian population persistence under global change.

This species was featured in news of week December 19, 2022:

In the age of biodiversity declines, the Harlequin frogs (genus Atelopus) have become poster frogs for amphibian conservation. The Jambato, Atelopus ignescens, is a Harlequin frog species thought to have gone extinct in the late 1980s -- until a single population in Angamarca, Ecuador, was rediscovered in 2016. In 2021, a team of scientists led a year-long effort to characterize the habitat, diet, abundance, and conservation threats to this remnant population (Vega-Yánez et al. 2024). From 12 surveys, Vega-Yánez and colleagues found a total of 71 individuals at sites along the Guambaine, Yallví, and Angamarca rivers in Cotopaxi, Ecuador. Of 41 tested individuals, 23 were positive for Bd but none showed signs of sickness, suggesting that the population is tolerant of Bd or that the Bd strain in the region is of low virulence. Although populations were hyperabundant in the 1980s, with up to 50 individuals encountered per m2; abundance has drastically decreased since then, and the species occupies only a small proportion of its prior habitat. Nevertheless, the presence of tadpoles, gravid females, and calling males indicate reproductive activity. Current threats to the species include predation by introduced rainbow trout, contamination of habitats by fecal material and chemicals used for agriculture, agricultural burning practices, and trampling by cows, among others. Because animals were often found in human-altered habitats, the conservation of the species will require coordinated efforts among scientists, community members, and the local government. The Alianza Jambato was founded in 2021 to bring these groups together to conserve the last refuge of the Jambato. What we have learned from these authors' fieldwork about the Jambato bring hope to the global community of amphibian conservationists. (Rebecca Tarvin)

References

Coloma, L. A. (2016). El Jambato negro del páramo, Atelopus ignescens, resucitó. IMCiencia. [link]

Coloma, L. A., Lotters, S. A., and Salas, A. W. (2000). ''Taxonomy of the Atelopus ignescens complex (Anura: Bufonidae): Designation of a neotype of Atelopus ignescens and recognition of Atelopus exiguus.'' Herpetologica, 56(3), 303-324.

Jaynes, K.E., M.I. Páez-Vacas, D. Salazar-Valenzuela, J.M. Guayasamin, A. Terán-Valdez, F.R. Siavichay, S.W. Fitzpatrick, and L.A. Coloma (2022). "Harlequin frog rediscoveries provide insights into species persistence in the face of drastic amphibian declines." Biological Conservation, 276(109784). [link]

La Marca, E., Lötters, S., Puschendorf, R., Ibáñez, R., Rueda-Almonacid, J. V., Schulte, R., Marty, C., Castro, F., Manzanilla-Puppo, J., García-Pérez, J. E., Bolaños, F., Chaves, G., Pounds, J. A., Toral, E., and Young, B. E. (2005). ''Catastrophic population declines and extinctions in neotropical harlequin frogs (Bufonidae: Atelopus).'' Biotropica, 37(2), 190-201.

Ron, S., Duellman, W. A., Coloma, L. A., and Bustamante, M. R. (2003). ''Population decline of the Jambato Toad Atelopus ignescens (Anura: Bufonidae) in the Andes of Ecuador.'' Journal of Herpetology, 37(1), 116-126.

Species Account Citation: AmphibiaWeb 2024 Atelopus ignescens: Jambato Harlequin Toad <https://amphibiaweb.org/species/55> University of California, Berkeley, CA, USA. Accessed Oct 22, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Oct 2024.

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