Hula painted frog

In 2013, a study published in Nature Communications revealed that in 2011 during a routine patrol at the Hula Nature Reserve, ranger Yoram Malka found the frog, which he immediately suspected as being the Hula painted frog, as he claimed he has been on the lookout for it for many years. Scientists confirmed that it was one of this rare species.[5][9][10] An ecologist with the Israel Nature and Parks Authority credited the rehydration of the area for the frog sighting.[14] On November 29, a second specimen was located in the same area.[5] The second Hula painted frog, a female, was found in swampy weeds twenty centimeters deep. It weighed 13 grams, half the weight of its male counterpart.[7] Since the discovery of the first specimen, at least ten more individuals have been found, all in the same area.[15]

In 2016, a team led by Professor Sarig Gafni of the Ruppin Academic Center's School of Marine Sciences discovered populations totaling several hundred individuals by searching in water at night, instead of in marsh mud, finding populations in 17 of the 52 Hula Valley water holes they surveyed.[16]

In 2017, an article published in the Molecular Ecology Journal, mentions of a group of scientists who investigated the suitable aquatic habitats for Hula painted frogs using the environmental DNA (eDNA) approach.[17] The Hula Lake once provided a habitat for many rare species including this frog. Since, the 2011 rediscovery of this species in this region (in the Hula nature reserve), consequent efforts to study and protect it started. However, these efforts have been hampered by the elusive nature of this species (that also prevented it being found from the 1950s-2010s). Since, there is a lack of systematic and efficient methodology to detect a rare amphibian or aquatic species, including this Hula painted frogs, they were designated “extinct”; until their rediscovery at a later stage.

Environmental DNA (eDNA) is becoming a ‘go-to’ tool for detecting species presence in aquatic environments. eDNA extraction (genetic material extracted through water filtrate) followed by quantitative Polymerase Chain Reaction (qPCR is a technique to amplify genetic material in real time) are highly sensitive methods which can increase the detection probability of rare organisms. To be more reliable the researchers concluded a site to be positive for the presence of Hula painted frogs if the water contains eDNA and if the physical presence of frog is detected as well. Thus, these researchers sampled 52 sites and found that 22 sites were positive for the presence of Hula painted frogs. Most of the positive sites were located in the regions around Hula Nature Reserve, Agamon ha-Hula, and Ein Te’o Nature Reserve. These regions overlap with the former Hula Lake region, and also contain organic, and colluvial-alluvial soils.

Such findings in the regions around reserved parks indicate the importance of nature parks in conservation of wild-life. The suitable habitats predicted by employing the eDNA are of great importance for identifying potential sites for future translocation to save this rare frog.

In 2018, another article published in Nature Scientific Reports, mentioned that this species has low abundance and dispersal capability, calling for urgent conservation measures.[18] The total estimate of potentially reproducing adults in this population (Nad) is found to be 234-235 individuals. They determined the population genetics of this species through a capture-recapture study on 118 adult frogs, and through micro-satellite analysis. Surprisingly, this frog has high genetic diversity (H_O = 0.771) and low inbreeding coefficient (F_IS = −0.018) with an effective population size estimate (Ne) of ~16–35. It could be due to the presence of one more unknown population or genetic admixture leading to a high genetic diversity and low inbreeding in spite of a less population.

Future research calls for understanding the habitat locations of another population which is not well studied, or different spots within the Hula valley location in which the frog species can be present. The aquatic habitats of this species are prone to disturbance and anthropogenic hazards which could imperil the survival of endangered Hula frogs. Thus outcomes of any future research dealing with prediction of the favorable dwelling habitats of this rare species, and their habitat characterization will be vital to protect the only living member of genus Latonia, by recommending characteristics of safer spots.