Photo: Adult individual of Telmatobius intermedius, in the stream of Allipacca, Puquio, Ayacucho, Peru. © Victor Vargas.
The story of our rediscovery begins in December of 2014, when we were surveying the habitat of the Andean condor (Vultur gryphus), in the Sondondo valley, a community of Chipao in the southern Andes of the Peruvian department of Ayacucho. At the end of our work, and in preparation of our return to Lima, we made a quick stop in the market of Puquio, a town in the province of Lucanas, in the Pacific slope of the Peruvian Andes, and the type locality of the Allipacca water frog (Telmatobius intermedius). We met a local seller of frog juice, a concoction of blended and liquified water frogs which is believed to have medicinal properties. We chatted with the seller, and after he showed us the frogs he used as juice ingredients, we realized that the frogs were individuals of Telmatobius, unlike other species we were familiar with. The seller also gave us tips concerning the likely source of these frogs, namely the small creeks of Allipacca near Puquio where children captured the frogs used for his market stand.
Armed with this information, we hiked to Allipacca and explored a couple of creeks, and quickly discovered tadpoles and frogs of the same Telmatobius species we had seen at the market stand. After comparing these specimens with a description in the literature, and the type specimens preserved at the natural history museum in Lima, we were able to identify this species as the Allipacca water frog T. intermedius, a species described by J. Vellard in 1951 and not reported again after that date.
Water frogs in the family Telmatobiidae are typical of the South American Andes, where 61 species are currently recognized of which 25 occur in Peru (AmphibiaWeb, 2019). These frogs are distributed in Chile, Bolivia, Peru, and Ecuador, from about 1800 m s.n.m (Aguilar, 2010) to the level of Andean glaciers around 5400 m asl. They live in ecosystems such as páramos, Andean subpáramos, the dry or humid puna, cloud forests, and other high elevation habitats. Species of Telmatobius are of semi-aquatic or exclusively aquatic habits (Lehr, 2005.). T. intermedius was previously known only from four specimens collected from its type locality in Allipacca (Vellard, 1955). Mr. F. Blancas first collected these frogs in 1950. Because the species had not been reported again following its description, the conservation status of this species was unknown. Therefore, Peruvian legislation (Supreme Decree No. 004-2014-MINAGRI) and the IUCN (until 2018) classified T. intermedius in the category of Data Deficient (DD) (Icochea et al., 2017). Despite our initial rediscovery, we still had an incomplete knowledge of its distribution, the state of its populations and its ecological requirements, although we think the species might be endemic to the Pacific slopes of the Andes of Ayacucho. The presence of a nearby protected area, the National Reserve Pampas Galeras, motivated us to survey the Reserve and surrounding creeks to determine whether T. intermedius occurred within protected areas (Aguilar et al., 2010).
In 2015, our initiative received support from the Amphibian Survival Alliance’s – ASA (http://www.amphibians.org/seedgrants/2015garcia/), and we were able to return to Puquio and Allipacca to resurvey the creeks where we had found populations of T. intermedius. We also had broadened our goals of assessing population status, identifying the main threats to the species, and estimating prevalence and intensity of infection by the fungus Batrachochytrium dendrobatidis. Chytridiomycosis is known to be especially virulent for species of Telmatobius. In addition to evaluating the Allipacca stream, we also assessed the streams of the Pampa Galeras National Reserve, about 30 km west of Puquio.
During these surveys starting in 2015, we sampled five streams in Allipacca, near the paved road connecting Puquio to San Andrés, following the protocol of Catenazzi et al. (2009). We evaluated transects of 100 m, and search in all possible tadpole or frog microhabitats (edges of the stream, deep areas, under stones, pools, etc.), we took data of the habitat such as dimensions of pools (width, depth), channel width, current speed, temperature, pH, conductivity, presence of plants, algae, insects, in addition to skin (frog) or mouthpart (tadpole) swab samples to determine the presence and intensity of the chytrid fungus.
Our findings suggest that T. intermedius is a threatened species. In the different surveys we carried out from 2015 to 2018, we could find the species in only two streams. The estimated area of occupation is thus very small (+ – 10 km2 approximately). We did not find T. intermedius within the Pampa Galeras Reserve. However, at Galeras, we found another species of Telmatobius, which we think may be new to science.
The frogs we captured in Allipacca match the description of the species. Adults of T. intermedius measure ~45 mm in snout-vent length. Anatomically, this frog has a wide head dorsolaterally, keratinized skin spicules throughout the body, both on the back and belly, tympanic membrane and tympanic ring absent, and supratympanic fold present. It has a variable and uniform gray dorsal coloration, a lighter belly with lower areas of the belly and orange thighs. Males have nuptial spicules scattered on thumbs and chest. The tadpoles have gray coloration and with a dark spot at the end of the tail. The eggs are placed in mass, adhered under the stones the current of water, wrapped in a transparent mucilaginous substance.
The two creeks inhabited by T. intermedius are located on the western flank of the Andean mountain range, on a moderate slope. These creeks traverse agricultural fields and rural roads where domestic animals and people circulate, is crossed by an asphalted road and is very close to the city of Puquio. The creek channels are of variable, but narrow width in certain sectors (up to 1.5 meters) and have clear running water that stagnates in moderately deep pools, with a substrate that is muddy, sandy or rocky depending on reach. The riparian vegetation is composed of shrubs and herbs typical of the Peruvian highlands. We found three other species of amphibians along these creeks, the toad Rhinella spinulosaand the marsupial frog Gastrotheca marsupiata, as well as another species of Telmatobius sp., possibly new.
We identified environmental contamination as a threat to these frog populations. The two streams were subject to runoff from the nearby agricultural fields and contamination by solid residues, and during one of our surveys, we found discarded jars of various agrochemicals close to the creek. Furthermore, many of the pools are eutrophic with abundant aquatic plants and algae as a consequence of the use of fertilizers and detergents. Heavily eutrophic pools are unsuitable for tadpoles and adults. Car traffic and rain erosion also promote siltation in both creeks.
Over-harvesting of adults for local and regional consumption is another threat. In recent years, over 10 thousand water frogs have been confiscated in Peru, mostly originating from southern Peru and all destined to human consumption in cities. It is presumed that climate change will cause the loss of quality and quantity of water due to melting glaciers and changes in local and regional climates. We expect this threat to intensify in the future, considering the current climate already exposes amphibians to extended periods without precipitation during the dry season. Future extremes might include prolonged droughts and flooding from extreme and sudden precipitation events.
By: Víctor J. Vargas G., Pablo Najarro, Marco Rivera, Oscar Chipana, Vladimir Díaz, Kevin Jaico and Alessandro Catenazzi