Journal of Threatened Taxa | www.threatenedtaxa.org | 26 August 2018 | 10(9): 12235–12246

Diversity and endemism of butterflies of montane forests of Eravikulam National Park in the Western Ghats, India

E.R. Sreekumar ¹, S. Nikhil ^{2 ,} K.G. Ajay ³ & P.O. Nameer ⁴

^1,2,3,4 Centre for Wildlife Studies, College of Forestry, Kerala Agricultural University, KAU Main Campus, Thrissur, Kerala 680656, India

¹ sreekumarcof@gmail.com, ² nikx.suresh02@gmail.com, ³ ajeee98@gmail.com, ⁴ nameer.po@kau.in (corresponding author)

doi: https://doi.org/10.11609/jott.4201.10.9.12235-12246 | ZooBank: urn:lsid:zoobank.org:pub:A8C9E500-277B-49E8-A32F-11011A921608

Editor: George Mathew, (Ex) Emeritus Scientist, KFRI, Peechi, India. Date of publication: 26 August 2018 (online & print)

Manuscript details: Ms # 4201 | Received 19 April 2018 | Final received 29 June 2018 | Finally accepted 18 July 2018

Citation: Sreekumar, E.R., S. Nikhil, K.G. Ajay & P.O. Nameer (2018). Diversity and endemism of butterflies of montane forests of Eravikulam National Park in the Western Ghats, India. Journal of Threatened Taxa 10(9): 12235–12246; https://doi.org/10.11609/jott.4201.10.9.12235-12246

Copyright: © Sreekumar et al. 2018. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

Funding: Kerala Agricultural University.

Competing interests: The authors declare no competing interests.

Acknowledgements: We thank Dr. Saji, K. for helping us to confirm the identity of the butterfly species and Sevantharaj for the support in the field. We are grateful to Abha, M.K., Abhirami, M.J., Anjali, J., Arjun, R., Devika, V.S. and Syamili, M.S., for various support. We also express our gratitude to Wildlife Warden, Munnar Wildlife Division and Assistant Wildlife Warden, Eravikulam NP for the logistics support. Dean, College of Forestry, Kerala Agricultural University is acknowledged for encouragement and support. We are grateful to the anonymous reviewers and the Subject Editor for their critical comments and useful inputs.

Abstract: In a study on the diversity and abundance of butterflies of montane forests of Eravikulam National Park in the Western Ghats, southern India, 85 species of butterflies belonging to six families were recorded. This include eight species of butterflies that are endemic to the Western Ghats and one Near-Threatened species according to IUCN Red List of Threatened Species. The family Nymphalidae, the brush-footed butterflies, was the major group of butterflies seen in the montane forests of Eravikulam National Park.

Keywords: Biodiversity hotspot, conservation, Hesperiidae, IUCN, Lycaenidae, Nymphalidae, Papilionidae, Pieridae, Riodinidae.

The Western Ghats is one of the biodiversity hot spots of the world (Myers et al. 2000). This region is rich in endemism including butterflies and has been of great interest for biogeography. The natural habitats in the Western Ghats is under tremendous pressure from the biotic influences (Jha et al. 2000; Mittermeier et al. 1998). Butterflies are suitable for biodiversity studies, because their taxonomy and geographic distribution are better understood compared to many other taxonomic groups (Pandhye et al. 2012). Butterflies are also regarded as good indicators of habitat quality as many species exhibit habitat preferences and seasonality (Larsen 1988; Kunte 1997). Butterflies are sensitive biota, which get severely affected by environmental variations and changes in forest structure (Pollard 1991). India has around 1,501 species of butterflies, out of which 336 species have been reported from the Western Ghats (Kunte et al. 2018). Of the 336 species of butterflies of the Western Ghats, 316 species have been reported from Kerala (Palot et al. 2012).

Although quite a few studies have been done on the butterflies of the Western Ghats (Gaonkar 1996; Kunte 2000, 2008; Kehimkar 2008; Padhye et al. 2012), very little is known about the butterflies of the montane habitats of the southern Western Ghats. Some of the earlier documentation on butterfly fauna from the Western Ghats include—100 species from Silent Valley National Park (Mathew & Rahamathulla 1993), 124 species from Parambikulam Wildlife Sanctuary (Sudheendrakumar et al. 2000), 75 species from Siruvani Reserve Forests (Arun 2003), 73 species from Shendurney Wildlife Sanctuary (Mathew et al. 2004), 74 species from Peechi-Vazhani Wildlife Sanctuary (Mathew et al. 2005), 24 species from Kalakkad-Mundanthurai Tiger Reserve (Ambrose & Raj 2005), 75 species from Anaikatty Reserve Forests (Eswaran & Pramod 2005), 53 species from Neyyar Wildlife Sanctuary (Mathew et al. 2007), and 282 species from the Kerala part of Nilgiri Biosphere Reserve (Mathew 2016). A checklist of butterflies of Western Ghats reported 834 species of plants as larval host plants of 320 butterflies (Nitin et al. 2018). In this paper we give an account of the butterfly fauna of the montane forests of Eravikulam National Park, based on a four-month long study done in 2014.

Study Area

Eravikulam National Park (ENP) (Fig. 1) is located between 10.08333–10.33333 ⁰N & 77.00–77.16 ⁰E in Idukki District of Kerala. The ENP forms part of the Munnar Hills, a part of the High Ranges of Western Ghats, which has six protected areas, viz., Anamudi Shola National Park, Pampadum Shola National Park, Mathikettan Shola National Park, Chinnar Wildlife Sanctuary, Kurinjimala Wildlife Sanctuary, and ENP; it is contiguous with the Palni Hills and Anamalai Hills. The ENP has an extent of 97km² and the terrain is undulating with grassland and shola, the stunted high altitude evergreen forests, as the dominant vegetation.

Climate: Eravikulam has a tropical montane climate. The average annual rainfall is about 5,000–6,500 mm. The area receives both south-west as well as north-east monsoons. The mean monthly minimum temperature is 11.9⁰C, while the mean monthly maximum temperature is 22.5⁰C. The altitude of ENP ranges from 1,800–2,695 m, typical of a montane landscape and the highest peak is Anamudi (2,695m).

Vegetation: The major plant communities found within ENP are grasslands, shrub lands, and forests. The terrain above 2,000m is covered primarily by grasslands (~60%), about 25% by shola forests, 8% by southern sub-tropfical hill forest, and 7% by shrubs (Menon 2001).

Methods

The study was conducted from September 2014 to December 2014. The whole of the study area was divided into nine blocks based on topography and drainage (Table 1) and five days each were spent on each of these blocks. At each basecamp two to three hour long transects were walked in the morning from 10:00–13:00 hr. No afternoon transects could be done because of the unfavourable weather conditions, such as mist, cloud and northeastern monsoon rains. During these transect walks, the butterflies were identified to the species level and the number of individuals were counted. Attempt was also made to photo-document every species of butterflies sighted. The butterflies were identified using the field guides of Kunte (2000) and Kehimkar (2008), and for taxonomy and nomenclature, we followed Kunte et al. (2018).

The abundance of the butterflies was calculated using the following method, species observed 80–100 % of the survey days were categorized as very common (VC), 60–80 % as common (C), 40–60 % as occasional (O), 20–40 % as rare (R) and below 20% as very rare (VR) (after Aneesh et al. 2013).

Results

A total of 85 species of butterflies belonging to six families such as, Papilionidae (10 species), Pieridae (15), Nymphalidae (36), Riodinidae (1), Lycaenidae (9), and Hesperiidae (14) (Table 2) were identified from the montane habitat of ENP. This included eight species that are endemic to the Western Ghats. They are Sahyadri Birdwing Troides minos, Nilgiri Clouded Yellow Colias nilagiriensis, Red-disc Bushbrown Heteropsis oculus, Nilgiri Four-ring Ypthima chenui, Palni Four-ring Ypthima ypthimoides, Palni Fritillary Argynnis castetsi, Nilgiri Tiger Parantica nilgiriensis and Striped Hedge Hopper Baracus subditus. The proportion between the endemic and non-endemic species of butterflies in the different basecamps are given in Fig 2. The basecamps such as Meenthotty, Rajamala, Anamudi and Eravikulam-Kolukkan recorded the greatest proportion of the endemic butterflies at ENP, while the Lakkam Kudi basecamp recorded the greatest proportion of the non-endemic species of butterflies. While the basecamps that recorded the greatest proportion of endemic butterflies were all within the core zone of the ENP, the Lakkam Kudi basecamp is very close to human habitation and the elevation is also the lowest. The Palni Four-ring found to be the most abundant species among endemic species was found in ENP.

Highest species diversity was observed in Lakkam Kudi area (51 species), followed by Poovar-Kumarikkal (47), Eravikulam-Kolukkan (45), Vembanthanni (43), Thirumudi (41), Anamudi (37), Varattukulam (33), Rajamala (29) and Meenthotty (13) (Fig. 3). The relative abundance of the butterflies was highest in the family Nymphalidae (57.6%), followed by Pieridae (25%) and Papilionidae (10.4%). The other three butterfly families account for the remaining 7% of the butterflies of ENP (Fig. 4).

The only threatened species of butterfly recorded as per the IUCN category was the Nilgiri Tiger Parantica nilgiriensis. It belonged to the Near Threatened category (Lepidoptera Specialist Group 1996). The relative abundance study revealed that 27.05% of species of butterflies belonged to very rare (VR) followed by 28.24% of species that were rare (R) (Table 2).

This is the first ever documentation of the butterflies of a montane habitat in the Western Ghats, which highlights the significance of these habitats on the conservation of high altitude, endemic butterflies of the Western Ghats.

Table 1. Basecamp details of the study locations at Eravikulam National Park (modified after Praveen & Nameer 2015)

Camps	Altitude (m)	Habitats
Rajamala	1,750	Shola, grasslands, rocky out-crops and shrubs, adjacent to tea plantations
Meenthotty	1,950	Shola, grasslands, rocky out-crops, adjacent to tea plantations and tribal settlements
Anamudi	2,150	Shola, grasslands, adjacent to tea plantations
Lakkam Kudi	1,450	Shola, grasslands, adjacent to tea plantations, coffee plantation and tribal settlements
Thirumudi	1,625	Shola, grasslands, adjacent to tribal settlements
Varattukulam	2,100	Shola, grasslands, adjacent to degraded grasslands
Poovar - Kumarikkal	2,125	Shola, grasslands
Vembanthanni	2,125	Shola, grasslands
Eravikulam - Kolukkan	2,180	Shola, grasslands

Table 2. Checklist of butterflies of Eravikulam National Park

Common English name/Family	Scientific name	Species authority	Image number	Abundance
Family Papilionidae
Sahyadri Birdwing*	Troides minos	Cramer, 1779	1	O
Common Rose	Pachliopta aristolochiae	Fabricius, 1775	2	VR
Crimson Rose	Pachliopta hector	Linnaeus, 1758	3	O
Common Bluebottle	Graphium sarpedon	Linnaeus, 1758	4	VC
Tailed Jay	Graphium agamemnon	Linnaeus, 1758	5	R
Lime Swallowtail	Papilio demoleus	Linnaeus, 1758	6	O
Red Helen	Papilio helenus	Linnaeus, 1758	7	C
Common Mormon	Papilio polytes	Linnaeus, 1758	8	C
Blue Mormon	Papilio polymnestor	Cramer, 1775	9	C
Paris Peacock	Papilio paris	Linnaeus, 1758	10	O
Family Pieridae
Lemon Emigrant	Catopsilia pomona	Fabricius, 1775	11	C
Mottled Emigrant	Catopsilia pyranthe	Linnaeus, 1758	12	O
Spotless Grass Yellow	Eurema laeta	Boisduval, 1836	13	VC
One-spot Grass Yellow	Eurema andersoni	Moore, 1886	14	VR
Common Grass Yellow	Eurema hecabe	Linnaeus, 1758	15	O
Three-spot Grass Yellow	Eurema blanda	Boisduval, 1836	16	R
Nilgiri Clouded Yellow*	Colias nilagiriensis	Felder & Felder, 1859		VR
Indian Jezebel	Delias eucharis	Drury, 1773	17	R
Asian Cabbage White	Pieris canidia	Linnaeus, 1768	18	VC
Common Gull	Cepora nerissa	Fabricius, 1775	19	R
Lesser Gull	Cepora nadina	Lucas, 1852		VR
Pioneer	Belenois aurota	Fabricius, 1793	20	C
Common Albatross	Appias albina	Boisduval, 1836	21	C
Yellow Orange-tip	Ixias pyrene	Linnaeus, 1764	22	O
Great Orange-tip	Hebomoia glaucippe	Linnaeus, 1758		C
Family Nymphalidae
Common Evening Brown	Melanitis leda	Linnaeus, 1758	23	VR
Common Treebrown	Lethe rohria	Fabricius, 1787	24	R
Tamil Bushbrown	Mycalesis subdita	Moore, 1892	25	R
Red-disc Bushbrown*	Telinga oculus	Marshall, 1880	26	VC
Common Four-ring	Ypthima huebneri	Kirby, 1871	27	O
Common Five-ring	Ypthima baldus	Fabricius, 1775	28	C
Nilgiri Four-ring*	Ypthima chenu	Guérin-Méneville, 1843	29	R
Palni Four-ring*	Ypthima ypthimoides	Moore, 1881	30	VC
Tawny Coster	Acraea terpsicore	Linnaeus, 1758	31	O
Rustic	Cupha erymanthis	Drury, 1773	32	R
Common Leopard	Phalanta phalantha	Drury, 1773	33	R
Palni Fritillary*	Argynnis castetsi	Oberthür, 1891	34	R
Common Sailer	Neptis hylas	Linnaeus, 1758	35	O
Commander	Moduza procris	Cramer, 1777	36	VR
Clipper	Parthenos sylvia	Cramer, 1775	37	VR
Angled Castor	Ariadne ariadne	Linnaeus, 1763	38	O
Common Castor	Ariadne merione	Cramer, 1777		VR
Map Butterfly	Cyrestis thyodamas	Doyère, 1840	39	R
Common Beak	Libythea lepita	Moore, 1857	40	O
Yellow Pansy	Junonia hierta	Fabricius, 1798	41	O
Lemon Pansy	Junonia lemonias	Linnaeus, 1758	42	R
Chocolate Pansy	Junonia iphita	Cramer, 1779	43	R
Painted Lady	Vanessa cardui	Linnaeus, 1758	44	R
Indian Red Admiral	Vanessa indica	Herbst, 1794	45	VR
Blue Admiral	Kaniska canace	Linnaeus, 1763	46	R
Great Eggfly	Hypolimnas bolina	Linnaeus, 1758	47	O
Danaid Eggfly	Hypolimnas misippus	Linnaeus, 1764	48	VR
Glassy Tiger	Parantica aglea	Stoll, 1782	49	R
Nilgiri Tiger*	Parantica nilgiriensis	Moore, 1877	50	VC
Blue Tiger	Tirumala limniace	Cramer, 1775	51	VC
Dark Blue Tiger	Tirumala septentrionis	Butler, 1874	52	VC
Plain Tiger	Danaus chrysippus	Linnaeus, 1758	53	R
Striped Tiger	Danaus genutia	Cramer 1779	54	R
Common Crow	Euploea core	Cramer, 1780	55	C
Double-branded Crow	Euploea sylvester	Fabricius, 1793	56	O
King Crow	Euploea klugii	Moore, 1857	57	O
Family Riodinidae
Double-banded Judy	Abisara bifasciata	Moore, 1877	58	VR
Family Lycaenidae
White Hedge Blue	Udara akasa	Horsfield, 1828	59	C
Common Hedge Blue	Acytolepis puspa	Horsfield, 1828	60	VR
Pale Grass Blue	Pseudozizeeria maha	Kollar, 1844	61	R
Tiny Grass Blue	Zizula hylax	Fabricius, 1775	62	VR
Oriental Grass Jewel	Freyeria putli	Kollar, 1844		VR
Forget-me-not	Catochrysops strabo	Fabricius, 1793	63	R
Pea Blue	Lampides boeticus	Linnaeus, 1767	64	C
Common Cerulean	Jamides celeno	Cramer, 1775	65	R
Common Lineblue	Prosotas nora	Felder, 1860	66	VR
Family Hesperiidae
Common Banded Awl	Hasora chromus	Cramer, 1780	67	VR
Common Awlking	Choaspes benjaminii	Guérin-Méneville, 1843		VR
Water Snow Flat	Tagiades litigiosa	Möschler, 1878	68	R
Common Yellow-breasted Flat	Gerosis bhagava	Moore, 1865	69	VR
Fulvous Pied Flat	Pseudocoladenia dan	Fabricius, 1787		VR
Dingy Scrub Hopper	Aeromachus dubius	Elwes & Edwards, 1897	70	C
Restricted Demon	Notocrypta curvifascia	Felder & Felder, 1862	71	VR
Striped Hedge Hopper*	Baracus subditus	Moore, [1884]	72	O
Giant Redeye	Gangara thyrsis	Fabricius, 1775		VR
Rounded Palm-redeye	Erionota torus	Evans, 1941	73	VR
Tawny-spotted Grass Dart	Taractrocera ceramas	Hewitson, 1868	74	O
Dark Palm-Dart	Telicota bambusae	Moore, 1878	75	R
Oriental Variable Swift	Parnara bada	Moore, 1878		R
Blank Swift	Caltoris kumara	Moore, 1878	76	VR

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