Description
Male Allobates zaparo have a snout to vent length range of 27.0 - 30.5 mm. Females have a snout-vent range between 26.5 - 30.5 mm. The snout is somewhat truncated to rounded in the dorsal aspect and rounded in the lateral aspect. The canthus rostralis is rounded and the loreal region is somewhat concave. The distance between eye and nostril is smaller than the eye diameter. The interorbital width is slightly longer than the width of the upper eyelid. The pupil is horizontal and rounded. The tympanum is half the diameter of the eye and the posterodrosal region is hidden. The skin on their dorsal surface of the body and limbs is granular in texture, but smooth along their ventral surface of the body and limbs. The fingers are unwebbed with the first being longer than the second and having discs that are relatively small. The hindlimbs have a strong, short tarsal fold with a bend at the proximal end located between the inner metatarsal tubercle and heel fold at the distal end and extending a third of the distance. There is a moderately developed tarsal tubercle. The toes have basal webbing between toes II, III, and IV (Silverstone 1976).

the fingers do not have webbing or fringes, and disks of the second, third and fourth fingers are small and less than 1.5 times the width of the fingers. This species toe tips are rounded. The toes are webbed around the base of each toe and the webbing does not extend along the length of the toe. Males of this species lack nuptial pads. [citation is incorrect, when correct citation is found, add back to appropriate place]

Allobates zaparo resembles several other members of closely related families. Epipedobates anthonyi is visually similar, but is smaller in size and has a light median dorsal stripe. Epipedobates boulengeri is also smaller and lacks the red dorsum of A. zaparo. Epipedobates espinosai is smaller than A. zaparo. Epipedobates tricolor has green bones and a light median dorsal stripe, while A. zaparo lack this stripe and has white bones. Both A. zaparo and Ameerega parvulus have a red dorsum, but A. zaparo is larger and has basal toe webbing. Allobates zaparo and Allobates femoralis are closely related and are visually similar species within the genus. However, A. zaparo has a red dorsum, usually lacks the light lateral stripe that A. femoralis has, and has a small or absent pale proximodorsal thigh spot compared to the large one in A. femoralis (Silverstone 1976).

In life, the dorsum of the body is red to brick-red in color outlined with thin or interrupted light-brown to copper brown lateral lines that start at the snout and extend posteriorly. The black sides of the head and flanks are bordered above by the brown lateral line and below by a white ventrolateral stripe that may become blue as it moves posteriorly. There is a greenish yellow strip on the upper lip. The dorsal surface of the forelimbs is light brown, with black or dark brown spots. The axilla region ranges from yellow to orange. The dorsal portion of the hindlimbs has a black background color, with blue-grey molting. The ventral and posterior surfaces of the thigh and calf are blue with black reticulations. The throat and chest are black, with some specimens having a blue sheen. The black extends to the belly where it becomes mottled or marbled with pale blue. The blue continues as a stripe until reaching the axillary region, which is orange in coloration. The throat is black with faint blue coloration. The stomach region is primarily blue with black splotches. The black iris has a thin band of bronze to copper color around the pupil (Silverstone 1976).

In preservative, the granules on the dorsum are golden-brown surrounded by black. The dorsal side of both forelimbs and hindlimbs is grey in color, with faint black banding. Some individuals have a white spot on the dorsal surface of the limbs where they meet with the body. The sides of the head and body and the ventral surfaces of the head, body, and limbs maintain their black coloration. The blue coloration becomes white or grey. The lateral line may be visible on the snout, canthus, and upper eyelid or may disappear. The ventrolateral line may also become white, interrupted, or disappear. A white stripe extends from the dorsal side of the forelimbs forward across the upper lip before terminating at the nostrils (Silverstone 1976).

There are geographic differences in A. zaparo coloration and patterning. Allobates zaparo is a Batesian mimic, which mimics the coloration of toxic species, Ameerega bilinguis and Ameerega parvulus, with which it lives in sympatry. All three species have a red granular dorsum, with the toxic species differing by variations in axilla and groin coloration. In the Northern Ecuadorian Amazon, A. zaparo resembles the slightly toxic A. bilinguis, whereas in the Southern Ecuadorian Amazon, it resembles the highly toxic species A. parvulus. Where all three species live in sympatry, A. zaparo resembles A. bilinguis (Darst and Cummings 2006).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Ecuador, Peru

View distribution map in BerkeleyMapper.

This species has a range that extends from La Cordillera de los Llanganates in central Ecuador, east of the Andes, and over the border into Peru. This species is found in rolling hills regions. Their habitat consists of old growth and well-regenerated secondary lowland tropical rainforest (Icochea et al. 2004). Specimens have been collected along tropical humid rivers and their tributaries in the Ecuadorian Andean Cordillera, which flows into the Amazonian foreland (Grant et al. 2006), at elevations ranging from 230 to 1000 m above sea level (Silverstone 1976). Within Peru, this species exists along the northwest border, reaching as far inland as Zona Reservada Pucacuro. The species is unprotected in Peru, but occurs within Yasuni National Park in Ecuador (Icochea et al. 2004).

Life History, Abundance, Activity, and Special Behaviors
Allobates zaparo is an abundant, diurnal species that can usually be found within the leaf litter. This species is terrestrial, but has reproduction tied to water, and so is found near slow moving tropical rivers and their mountain tributaries (Silverstone 1976).

Males call from concealed positions on top of the leaf litter and from crevices in boulders to attract females. Calls could be heard in the late afternoon and early evening. The calls consisted of discrete single pulses without much frequency modulation. At 25.8 degrees Celsius in the leaf litter, the call had a mean multinote call duration of 1.524 ± 0.594 s, a mean interval between call duration of 2.965 ± 1.288 s, and a call rise time of 0.540 ± 0.126 s. Each unit of repetition lasted an average of 0.185 ± 0.012 seconds with an average of 0.313 ± 0.021 seconds between units and 3.216 ± 0.199 units per second. The mean number of calls per second was 0.370 ± 0.096. The mean number of pulses per call was 10.375 ± 3.543 and the mean number of pulses per second was 6.709 ± 0.398. Pulses consisted of one initial note that lasted 0.072 ± 0.011. The single middle pulse note lasted 0.082 ± 0.010 seconds. The initial peak frequency is 2952.900 ± 67.551 Hz and the middle peak frequency is 3001.707 ±99.984 Hz. The calls are loud and elaborate, which puts them at risk of predation, but they pose aposematic coloration that mimics sympatric toxic species, protecting them (Santos et al. 2014).

Unlike the basal members Dendrobatoidae, members of the genus, Allobates, do not have cephalic amplexus (Vences et al. 2000).

Ovipositing usually takes place on leaves. When the larvae hatch, they are carried to water, where they mature and metamorphose into adults (Icochea et al. 2004, IUCN 2018). Parental transport of larvae on the dorsum is a synapomorphy of all Dendrobatidae, independently lost in only two species. Although it is not clear which sex is responsible for tadpole transport in A. zaparo, its sister group, A. femoralis, uses biparental transport (Grant et al. 2006).

Where both A. bilinguis and A. parvulus species cohabit, A. zaparo mimics the less toxic species: A. bilinguis. This is the opposite of what would initially be predicted, that it would mimic the more toxic and more abundant species. The theory behind this is that the more toxic species teaches predators a general avoidance response, from which all species that look somewhat similar to the highly toxic species benefit. The less toxic species teaches predators a highly targeted avoidance response where they will only avoid eating individuals that look precisely like the less toxic species. By mimicking the less toxic individual, A. zaparo enjoys the benefits of both types of predator learning (Darst and Cummings 2006).

This species appears to be a dietary generalist. While a large fraction of its diet is made up of ants, specimens collected at different sites have varying proportions of ants in their diet, ranging anywhere from 11% to 74% (Darst et al. 2005).

In the region, little is known about potential predators for species in the family Dendrobatidae, but birds are suspected predators and have been found to eat A. zaparo in experimental settings (Darst and Cummings 2006).

Trends and Threats
The population trend for this species was determined to be stable in 2018 (IUCN), and the species is not believed to be under threat. However, a major threat to the species is localized habitat loss that has occurred as a result of habitat conversion to agricultural activities (Icochea 2004, IUCN 2018). Compared to forested areas, this species experiences a 90% reduction in abundance in areas that have been converted to plantations or pastures (Beirne et al. 2013).

While unprotected in Peru, this species does occur within Yasuni National Park in Ecuador (Icochea et al. 2004, IUCN 2018).

Possible reasons for amphibian decline

General habitat alteration and loss
Intensified agriculture or grazing

Comments
The species authority is: Silverstone, P.A. (1976). "A revision of the poison arrow frogs of the genus Phyllobates Bibron in Sagra (Family Dendrobatidae)." Natural History Museum of Los Angeles County Science Bulletin 27: 1-53.

Prior to 2006, the genus, Allobates was considered a sister clade to some species of Colostethus, specifically, C. humiis, C. marchesianus, C. talamancae and C. triliatus (Vences et al. 2003). However, after Grant et al.'s (2006) phylogenetic analysis, those species were reassigned to Allobates. The next genus that Vences et al. (2003) found to be related to Allobates was then named Nephelobates, but was also renamed by Grant et al. (2006) to Aromobates. Within Allobates, several studies place A. zaparo sister to A. femoralis (Vences et al. 2003, Grant et al. 2006, Simões et al. 2010, Santos et al. 2014).

The species epithet, “zaparo”, originates from the Záparo Indians, native to the same region of eastern Ecuador (Silverstone 1976)

Allobates zaparo has, at various times, been placed in the genus, Phyllobates by Silverstone in 1976, Dendrobates by Myers, Daly, and Malkin in 1978, and Epipedobates by Myers in 1987 (IUCN 2018).

This species lacks the ability to concentrate alkaloids like other members of the Dendrobatidae family, but still resembles them in appearance, marking them as a Batesian mimic (Darst et al. 2005).

References

Beirne, C., Burdekin, O., Whitworth, A. (2013). ''Herpetofaunal responses to anthropogenic habitat change within a small forest reserve in Eastern Ecuador.'' Herpetological Journal, 23, 209-219.

Darst, C. R., Menendez-Guerrero, P. A., Coloma, L. A., and Cannatella, D. C. (2005). ''Evolution of dietary specialization and chemical defense in poison frogs (Dendrobatidae): A comparative analysis.'' The American Naturalist, 165, 56-69.

Darst, C.R., Cummings, M. (2006). ''Predator learning favours mimicry of a less-toxic model in poison frogs.'' Nature, 440, 208-211.

Grant, T., Frost, D. R., Caldwell, J. P., Gagliardo, R., Haddad, C. F. B., Kok, P. J. R., Means, D. B., Noonan, B. P., Schargel, W. E., and Wheeler, W. C. (2006). ''Phylogenetic systematics of dart-poison frogs and their relatives (Amphibia: Athesphatanura: Dendrobatidae).'' Bulletin of the American Museum of Natural History, (299), 1-262.

IUCN SSC Amphibian Specialist Group. 2018. “Allobates zaparo”. The IUCN Red List of Threatened Species 2018: e.T55039A89198822. Downloaded on 26 July 2018.

Icochea, J., Coloma, L.A., Ron, S., Jungfer, K.-H., Angulo, A., Cisneros-Heredia, D. (2004). “Allobates zaparo”. The IUCN Red List of Threatened Species 2004: e.T55039A11244484. http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T55039A11244484.en

Santos, J.C., Baquero, M., Barrio-Amoros, C., Coloma, L.A., Erdtmann, L.K., Lima, A.P., Cannatella, D.C. (2014). ''Aposematism increases acoustic diversification and speciation in poison frogs.'' Proceedings of the Royal Society B, 281, 20141761.

Silverstone, P.A. (1976). ''A revision of the poison arrow frogs of the genus Phyllobates Bibron in Sagra (Family Dendrobatidae).'' Natural History Museum of Los Angeles County Science Bulletin, 27, 1-53.

Simões, P.I., Lima, A.P., Farias, I.P. (2010). ''The description of a cryptic species related to the pan-Amazonian frog Allobates femoralis (Boulenger 1883) (Anura: Aromobatidae).'' Zootaxa, 2406, 1-28.

Vences, M., Kosuch, J., Boistel, R., Haddad, C.F.B., La Marca, E., Loetters, S. and Veith, M. (2003). ''Convergent evolution of aposematic coloration in Neotropical poison frogs: A molecular phylogenetic perspective.'' Organisms Diversity and Evolution, 3, 215-226.

Vences, M., Kosuch, J., Lötters, S., Widmer, A., Jungfer, K. H., Köhler, J., Veith, M. (2000). ''Phylogeny and classification of poison frogs (Amphibia: Dendrobatidae), based on mitochondrial 16S and 12S ribosomal RNA gene sequences.'' Molecular Phylogenetics and Evolution, 15, 34-40.

Species Account Citation: AmphibiaWeb 2018 Allobates zaparo: Sanguine Poison-arrow Frog <https://amphibiaweb.org/species/1676> University of California, Berkeley, CA, USA. Accessed Nov 12, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 12 Nov 2024.

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