Description
Raorchestes luteolus can be distinguished from congeners by the following combination of characters; (1) medium-sized adult males (SVL 26.8 mm, +/- 1.7 mm, n = 7); (2) pointed snout; (3) rounded canthus rostralis; (4) yellow to yellowish-brown dorsum, uniformly granular in texture and usually with 4-6 faint discontinuous stripes running from snout to vent; (5) loreal and tympanic regions golden yellow to yellowish brown (Biju and Bossuyt 2009). Gururaja et al. (2007) noted that the female in an amplected pair was larger but did not provide a measure of the female size.

Males are yellow during breeding season and cream in the non-breeding season. The pupil is golden and the eyes have a complete blue ring on the outer margins of the pupil (Gururaja et al. 2007).

This species can be distinguished from the similar species R. travancoricus by having a pointed snout (vs. oval snout in R. travancoricus), rounded canthus rostralis (vs. indistinct), uniformly granular dorsum (vs. shagreened), yellowish sides (vs. light brown), and lack of a dark-brown streak on either side of the snout (vs. presence of dark-brown snout streaks) (Biju and Bossuyt 2009).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: India

View distribution map in BerkeleyMapper.

Endemic to the Western Ghats region of India, in Karnataka state (Jog Falls, Kempholay, Kirundadu, Kudremukh-Malleshwaram, Madenadu, Mavingundi, Mercara, Muthodi, Sakleshpur, and Shimoga District). It has been found in disturbed habitat near coffee plantations, adjacent to secondary forest (Biju and Bossuyt 2009). In Shimoga District, this species was found mainly at mid-altitudinal range (500-700 m) in evergreen/semi-evergreen/moist deciduous forest patches, generally within vegetated areas described as Myristica swamps. Individuals have been found on leaves and stems of shrubs, at about 1 m from the ground (Gururaja et al. 2007).

Life History, Abundance, Activity, and Special Behaviors
A recent paper (Gururaja et al. 2007) described a single pair in amplexus moving from the shrubs to a cavity inside a leaf-litter heap on the ground, in an area lacking any standing bodies of water, and concluded that this is indicative of possible understory nesting behavior. The mating call has been described as a long trill with a short introductory phase having fast pulses and a long main phase with slowly repeated pulses (Kuramoto and Joshy 2003). It has also been described as a shrill "treeek" followed by a series of "tink" notes (Gururaja et al. 2007). Two different call types have been noted: repeated short-duration calls (0.27-0.42 sec) and long-duration calls ranging from 1.42 sec to 71.92 sec in duration, at a frequency of 2.35-2.41 kHz (Gururaja et al. 2007). In Mercara, males began calling at dusk from under the leaf litter, and then climbed into vegetation about 1 m from the ground and continued calling until about 22:00 h (Biju and Bossuyt 2009).

Larva
Presumably this species is a direct developer as are all other species in the genus Raorchestes.

Trends and Threats
This species is poorly known. Habitat loss and degradation may be a threat, since the Western Ghats in general are undergoing increased human settlement. This species may occur within Kudrumkh National Park but has not yet been confirmed to occur there (Das 2004).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities

Comments

This species was described by Kuramoto and Joshy (2003), as Philautus luteolus. Subsequently Philautus neelanethrus (described by Gururaja et al. 2007 from Shimoga District in Karnataka state) was synonymized with P. luteolus by Biju and Bossuyt (2009). This species was then transferred from the genus Philautus into the genus Raorchestes by Biju et al. (2010).

References

Biju, S. D., Shouche, Y., Dubois, A., Dutta, S. K., and Bossuyt, F. (2010). "A ground-dwelling rhacophorid frog from the highest mountain peak of the Western Ghats of India." Current Science, 98(8), 1119-1125. [link]

Biju, S. D., and Bossuyt, F. (2009). ''Systematics and phylogeny of Philautus Gistel, 1848 (Anura, Rhacophoridae) in the Western Ghats of India, with descriptions of 12 new species.'' Zoological Journal of the Linnean Society, 155, 374-444.

Das, I. (2004). Raorchestes luteolus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. www.iucnredlist.org. Downloaded on 05 October 2011.

Gururaja, K. V., Aravind, N. A., Ali, S., Ramachandra, T. V., Velevan, T.P ., Krishnakumar, V., and Aggarwal, R. K. (2007). ''A new frog species from the central Western Ghats of India, and its phylogenetic position.'' Zoological Science, 24, 525-534.

Kuramoto, M., and Joshy, S. H. (2003). ''Two new species of the genus Philautus (Anura: Rhacophoridae) from the Western Ghats, southwestern India.'' Current Herpetology, 22, 51-60.

Species Account Citation: AmphibiaWeb 2022 Raorchestes luteolus: Coorg Yellow Bush Frog <https://amphibiaweb.org/species/6262> University of California, Berkeley, CA, USA. Accessed Nov 22, 2024.

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

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