AMPHIBIAWEB
Sanguirana igorota
Balbalan Frog
family: Ranidae
Conservation Status (definitions)
IUCN (Red List) Status Vulnerable (VU)
CITES No CITES Listing
Other International Status None
National Status None
Regional Status None

 

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Description
Description: Rana igorota is a semi-aquatic, medium-sized frog. SVL ranges from 33-39 mm. The dorsal skin is also smooth for the most part, except for some scattered tubercles toward the posterior part. There is a very narrow, distinct, tubercular, dorsolateral, glandular fold present. The belly is granular posteriorly and the chin and throat are smooth. The posterior and inferior aspects of the femur are largely granular. The skin on its head is smooth. Its head is much longer in size than it is wide. The snout is elongate and the eye is a little shorter than the snout. The nostrils are closer to the snout than eye. The tympanum is large, separated from the eye by a distance less than half the diameter of the tympanum. The distance between the nostrils is slightly greater than the distance from eye to the nostrils. Its posterior nasal apertures are moderate in size, hidden by an overhanging jaw. No vocal sacs have been observed on this species. It has vomerine teeth in two series: one lying between and the other behind the posterior nasal apertures. Its tongue is large with two elongate horns widely separated at the base. The hind limb is brought forward, with the tibiotarsal articulation reaching about halfway between the eye and nostril. Fingers have very broad discs equal to two-thirds the diameter of tympanum. The discs are smaller on the two inner fingers with the first finger greatly thickened at base. Toes have well developed, somewhat pointed discs about the size of the disc on the second finger. These toes are about four-fifths webbed. The webbing reaches the fourth toe disk by only a very narrow membrane. (Taylor 1922).

R. igorota can be differentiated from R. luzonensis by coloration patterns, a shorter hind limb, and a tibiotarsal articulation that does not reach beyond the nostril. The snout is not as flattened. It has a narrower interorbital area. The disks are not as wide (Taylor 1922).

Coloration: Dorsally, its body is green to olive-green variegated with numerous rounded bronze spots. Its sides are yellow-green, spotted with olive. The belly is yellow and the tympanum is brown. The limbs are strongly barred with green and bronze. The toe pads are a creamy yellow. The dorsolateral glandular folds are golden yellow (Taylor 1922).

Variation: There is considerable variation in its markings. In some specimens, the rounded spots on the back and flanks are dim. Some of the younger specimens were nearly yellow in life. The distinctness of the granules on the back and femur varies. Some specimens have minute spine-like tubercles on the lower jaw, throat, and breast, and in the area about the tympanum. This may be sexual variation (Taylor 1922).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Philippines

 

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R. igorota occurs in the central Cordilleras on northern Luzon Island, Balbalan, and Kalinga in the Philippines. It has been recorded at altitudes between 850 m and 950 m above sea level.

It is able to tolerate a small amount of disturbance in its habitat of cool streams and rivers in montane forest. It most likely breeds in streams and lays its eggs in water (Diesmos et al. 2004).

Life History, Abundance, Activity, and Special Behaviors
It is found on the edge of small brooks. When disturbed, it dives into the water and hides under rocks (Taylor 1922).

Trends and Threats
The main threat to this species is habitat loss. There is extensive deforestation in the lower montane and lowland forests in the Cordilleras causing severe fragmentation and loss of quality of habitat. The montane forests are either being converted to vegetable farms or are being developed for real estate. There is a need for increased protection of the remaining tracts of intact lowland and montane rainforest in the Cordilleras. There is a decreasing population trend. However, this species can be found in high numbers in suitable habitats (Diesmos et al. 2004).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Urbanization
Habitat fragmentation

Comments

The name of the species is derived from Igorot, the generic name applied to the peoples inhabiting the central part of northern Luzon.

It was removed from the synonymy of Hylarana luzonensis by Brown, McGuire, and Diesmos in 2000.

References

Diesmos, A., Alcala, A., Brown, R., Afuang, C., Gee, G., Hampson, K., Diesmos, M.L., Mallari, A., Ong, P., Ubaldo, D., Gutierrez, B. 2004. Hylarana igorota. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.1. . Downloaded on 17 May 2010

Diesmos, A.C., Brown, R.M., McGuire, J.A. (2000). ''Status of some Philippines frogs referred to Rana everetti (Anura: Ranidae), description of a new species, and resurrection of R. igorota Taylor 1922.'' Herpetologica, 56, 81-104.

Frost, D.R. 2007. Amphibian Species of the World: an Online Reference. Version 5.1 (10 October, 2007). Electronic Database accessible at American Museum of Natural History, New York, USA. Hylarana igorota. Accessed on 18 May 2010.

Taylor, E. H. (1922). ''Additions to the Herpetological fauna of the Philippine Islands. II.'' Philippine Journal of Science, 21, 257-303.



Written by Steven Micheletti (smichele AT sfsu.edu), San Francisco State University
First submitted 2010-05-20
Edited by Brent Nguyen, Mingna (Vicky) Zhuang (2012-03-13)

Species Account Citation: AmphibiaWeb 2012 Sanguirana igorota: Balbalan Frog <http://amphibiaweb.org/species/5901> University of California, Berkeley, CA, USA. Accessed Oct 20, 2017.



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Citation: AmphibiaWeb. 2017. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 20 Oct 2017.

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