Butterfly Diversity Of Pune City Along Human Impact Gradient

Krushnamegh Kunte

4024, Survey No. 14/4, Warje, Pune, 4110 29. Email: krushnamegh@hotmail.com


Introduction

India hosts 1,501 species of butterflies (Gaonkar 1996), of which peninsular India hosts 350, and the Western Ghats, 331. Pune falls in the relatively species-poor, drier region of the northern Western Ghats. Above literature on biogeographic distribution and habitat preference indicates that the Pune district may harbour about 170 species (Kunte, unpubl.), of which 104 are so far reported from Pune urban area within 20 km radius. Remaining species are mostly forest dwellers and may not be found in the urban area. There is hardly any literature specific to Pune butterflies.

Methodology

While observations here are based on seasonal visits to many localities in and around Pune, I explored six sites more intensely, given their contrasting vegetation types and levels of disturbance (Kunte, 1997). The sites include the moist deciduous forests at Sinhgad hills, their extension at drier, forests and grasslands prone to fire and grazing, amidst deserted habitation around NDA, much drier, fire prone scrub and grasslands with little grazing, besides afforestation at Pachgaon, highly grazed but hardly burnt grasslands (so called `barren landí) at Malwadi, well-wooded campus S.P. College of with profusion of old trees, native trees, besides exotics ones, amidst a mosaic of concrete buildings, the marshes and scrub along Mutha riverbank at Dattawadi. Besides noting relative abundance and even seasonal counts (Kunte,1997), I also recorded larval host plants and their Phenology, besides nectar plants, larval host plants, predators, early stages of butterflies.

Results And Discussion

Diversity and distribution: Annexure depicts the distribution patterns of 104 butterfly species recorded so far. Some butterfly species, which perhaps evaded detection or precise field identity, may include Lineblues, other Blues, Swifts and Skippers. Further survey may not record more than 120 species from the study area. Table 1 summerises the annexure on terms of habitatwise species richness and uniqueness. Over two third are found in denser forest habitats such as valleys of Sinhagad and Peacock Bay, 11 of which found nowhere else. Scrub appears to be most species rich habitat frequented by three fourth the species though only two of these were exclusive to it, seldom recorded elsewhere. Forest, on the other hand harboured lower diversity with only 68 species, but highest level of uniqueness, with nearly a dozen species exclusive to it. Plantations also harboured two unique species, though low species richness. Agriculture and grassland harbour high and lowest species richness respectively though without any species being exclusive to them. Together, wilderness areas i.e. forest, scrub and grasslands harbour three fourth of the species, about a fourth of them being exclusive to wilderness zone. The plantations clogging the township, along with the agriculture represent more human impacted zone which harbours about two third of the total species recorded from Pune, but some of them have their larval food plants located in the wilderness zone. The habitat specialists include predominantly forest dwellers like the Bushbrown, few species of Yellows and Flats; while the Tailed Jay is a habitation specialists. The habitat generalists include Common Rose, Lime Butterfly, species of Grass Blues etc. found in variety of habitat types.

Seasonality :

Table 3 presents proportion of total species recorded along transects at four localities (Kunte, 1997) across seasons. This excludes sepcies with unreliably low abundances and the plantation fauna. Kunte (1997) describes in detail the seasonality patterns, technically termed flight periods, of species and groups, including factors affecting it. Butterflies in all habitats have distinct flight periods. Almost all butterflies have very short seasonal peaks, and they are either absent or rare in other seasons (Kunte, 1997). However, their interesting patterns probably reflect phenophases of their host plants. Some species occur throughout the year with a short population peak in a specific season, and some species occur only for a few months, such as the Spotless Grass Yellow and the Common Hedge Blue, respectively (at Sinhagad). A few species have a single, short flight period such as Lineblues (at Sinhagad) whereas some have two short peaks (e.g. Common Five-ring at Sinhagad). Yet others have just one, but fairly long flight period (e.g. Chocolate Pansy at Sinhagad). Although with little fluctuations, a few species (e.g. Common Evening Brown at Sinhagad) have similar abundance throughout the year. Most butterflies, in terms of number of individuals and number of species, fly in Pune during late monsoon and winter. The populations are low in spring and summer, probably due to fires at Peacock Bay and Pachgaon, and scarcity of water and ground flora at Malwadi and Sinhagad. Usually at all the sites, the populations start building from early monsoon and show the first peak in late monsoon, followed by a second peak in winter.

Fire and grazing impacts: Certain hillocks in Pune are grazed by migratory herds of sheep and resident livestock. Some are annually burned in uncontrolled and artificial fires. Intense grazing seriously alters composition of ground flora in grasslands. Cattle uproot grasses while feeding on them, and therefore decrease their density promote unpalatable herbs, at thecost of tall grasses such as at Malwadi. On the other hand, fire-afflicted site of Pachgaon host tall grasses but herbs are rare. Given these difference in larval and adult food resources, the butterfly fauna of Malwadi grasslands differes from the Pachgaon grasslands. For instance, species such as Grass Blues, Grass Jewel, Joker and Blue Pansy are much more common mainly at the fire-free site of Malwadi than Pachgaon, especially seen during winter. Since larval as well as imaginal stages of these butterfly species inhabit extremely disturbed vegetation, it is possible that they have evolved in secondary, naturally or artificially disturbed grasslands. Fires can occur naturally or be initiated by human beings. It plays a very important role since it affects the vegetation directly. However, despite affecting species composition, fire does not seem to affect species richness (Table 2). Butterflies such as common evening brown, plains cupid, spotless grass yellow, blue pansy, lemon pansy, painted lady and leopard were found at fire-free as well as at fire-afflicted sites. These species had more intense peaks at fire-afflicted areas with highly seasonal occurrence. On the other hand, in the fire-free areas their occurrence was less seasonal and spread across more seasons. Control of annual fires will be a singular, and perhaps the most important, effort at conserving butterflies in Pune.

Population changes: In the absence of earlier studies, it is impossible to quantify if certain butterflies have increased or decreased over the last decades. It is obvious that loss of habitat and increased use of inorganic pesticides in recent decades have adversely affected many butterfly species. Yet, no species might have gone locally extinct in Pune, given the long history of modification of the land in this region (Nalavade, this volume). In contrast, populations of at least two butterflies evergreen and semi-evergreen forest dwellers viz. Blue Mormon and the Plain Puffin have increased prominently in last 10 years, thanks to the home gardens that host theri larval host plants viz. Citrus spp. and Drypetes roxburghii respectively. Common Albatross and the Plain Puffin both feed on D. roxburghii and co-occur at the probable source population, Bheemashankar in the Western Ghats. But so far only the Plain Puffin has been successful in establishing in to the drier east aty Pune while only the Common Albatross has established itself in parts of moister, western Mumbai city. Populations of the Tailed Jay and the Common Mormon, species from evergreen and deciduous forests respectively seem increasing, benefiting from avenue and homestead plantation of larval host trees such as Polyalthia longifolia and Citrus spp. The plants apparently helped widen habitat preference of butterflies.

Conclusion :

Nearly half the species are recorded in the township, including various kinds of plantations of trees and shrubs like home gardens, public gardens, avenues etc. However, all of them may not survive if the natural vegetation like forest and grasslands surrounding the city vanish. For, some of the species seen around human habitation have their food plants or source populations in such wilderness zones skirting the township. Together, a fifth of the species are recorded primarily from such wilderness, rarely encountered in the city. These are thus most vulnerable to any further destruction of wilderness areas. This can be minimised by promoting these food plants (Kunte, 2000), whether herbs or climbers, rather than planting exotic trees. Controling hill fires is also a pressing need.

Acknowledgements :

Radhika Godbole helped me during the fieldwork while Dr. Makarand Dabak and Thomay Gay shared their perceptions especially about the past. My teachers such as Dr. Pendse of the S. P. College encouraged this extracurricular interest that cost my college schedule. I thank them all, besides cooperative family and friends.

Bibliography :

Evans, J. H. 1932. Identification of Indian Butterflies. BNHS (repr.). Mumbai.

Gaonkar, H. 1996. Butterflies of the Western Ghats with notes on those of Sri Lanka. A report to Centre for Ecological Sciences, Indian Institute of Science, Bangalore; Zoological Museum, Copenhagen and Natural History Museum, London.

Kunte, K. J. (unpbl.) Checklist of the Butterflies of the Western Ghats.

Kunte, K. J. 1996. Strange behavior of Mottled Emigrant males. J. Bombay Nat. His. Soc., 93(2):307-308.

Kunte, K. J. 1997. Seasonal patterns in butterfly abundance and species diversity in four tropical habitats in northern Western Ghats. J. Biosc., 22(5):593-603.

Kunte, K J. 1998. Common Silverline caterpillar feeding on Cadaba indica. J. Bombay Nat. His. Soc., 95(1):139.

Kunte, K. J. 1998. Plain Puffin: Behavior, life history and distribution. J. Bombay Nat. His. Soc., 95(1):137-139.

Kunte, K. J. 2000. Butterflies of Peninsular India. Indian Academy of Sciences, Bangalore and Universities Press, Hyderabad.

Larsen, T. B. 1987-88. The butterflies of the Nilgiri mountains of southern India (Lepidoptera: Rhopalocera). J. Bombay Nat. Hist. Soc., 84(1) to 85(1).

Nalavade S. B., this volume. Geography of Pune city.

Wynter-Blyth, M. A. 1957. Butterflies of the Indian Region. Bombay Natural History Society, Mumbai.


Table 1

Habitat type wise species richness

 

No. of total species

No. of Unique Species

Forest (F)

68

11

Scrub (S)

76

2

Grassland (G)

38

0

Plantations (P)

57

2

Agriculture (A)

69

0

Wild (F,S,G)

80

20

Impacted (P,A)

70

0

Table 2

Seasonal variation in species richness at the four sites

 

Feb.-Mar.

Apr.-May

Jun.-Jul.

Aug.-Sep.

Oct.-Nov.

Dec.-Jan.

Sinhagad

8

7

17

19

16

14

Peacock Bay

6

6

7

14

19

12

Pachgaon

4

3

14

25

18

21

Malwadi

14

8

10

14

18

12

ANNEXURE: Distribution and abundance of butterflies in Pune urban area

HABITATS: F-forest, S-Scrub, G-Grassland, P-Plantations, A-Agriculture
ABD (Abundance): A-Abundant, C-common, O-Occassional, R-rare, S-Stray

REMARKS: LC- Law College, PU- Pune University

The common names are adopted from Evans (1932) and Winter Blythe (1957). For scientific nomenclature, consult Gaonkar (1996).

Sno

Common Name

Abd

Habitats

Remarks

 

Family Papilionidae

     

1

Common Rose

C

FSGPA

 

2

Crimson Rose

O

FSPGA

 

3

Tailed Jay

C

P

 

4

Common Mime

S

 

source 40 km?

5

Lime

A

FSGPA

 

7

Common Mormon

C

FP

 

8

Blue Mormon

O

FP

increasing

 

Family Pieridae

     

9

Common Emigrant

A

FSPA

 

10

Mottled Emigrant

A

SGPA

 

11

Small Grass Yellow

C

FSGPA

 

12

Spotless Grass Yellow

A

FSGPA

Seasonal forms

13

Common Grass Yellow

A

FSGPA

 

14

Three-Spot Grass Yellow

?

F

rare, Sinhagad

15

Common Jezebel

C

FP

 

16

Psyche

C

FSPA

 

17

Common Gull

A

FSGPA

 

18

Pioneer Or Caper White

A

SGPA

 

19

Plain Puffin

O

P

fresh arrival

20

Striped Albatross

R

SGA

sporadic

21

Small Salmon Arab

S

SA

 

22

Small Orange Tip

C

SGA

 

23

Plain Orange Tip

R

SGA

 

24

Crimson Tip

R

SGA

only PU & LC

25

Large Salmon Arab

R

SGA

LC hill

26

White Orange Tip

O

FSPA

 

27

Yellow Orange Tip

S

FS

 

28

Common Wanderer

C

FSPA

 
 

Family Nymphalidae

     

29

Common Evening Brown

A

FSGPA

 

30

Common Treebrown

R

FS

 

31

Common Bushbrown

O

F

 

32

Common Threering

C

FSGA

 

33

Common Fivering

C

FS

 

34

Common Nawab

R

FPA

winter

35

Black Rajah

R

FSPA

winter

36

Tawny Coster

C

SGPA

 

37

Common Leopard

C

FSA

 

38

Common Sailer

C

FS

source at Sinhgad?

39

Common Baron

C

FPA

winter

40

Baronet Or Red Baron

R

FS

frequents Malwadi

41

Joker

O

SGA

localized

42

Angled Castor

R

SA

 

43

Common Castor

A

FSPA

 

44

Yellow Pansy

C

FSGPA

 

45

Blue Pansy

C

SGPA

 

46

Lemon Pansy

A

FSGPA

 

47

Peacock Pansy

C

FSPA

Waterbodies

48

Grey Pansy

C

FSPA

Waterbodies

49

Chocolate Pansy

C

F

 

50

Painted Lady

O

SGA

highly seasonal

51

Great Eggfly

O

FSPA

 

52

Danaid Eggfly

O

FSPA

 

53

South Indian Blue Oakleaf

R

F

 

54

Glassy Tiger

O

FSPA

 

55

Blue Tiger

C

FSPA

 

56

Plain Tiger

A

SGPA

 

57

Striped Or Common Tiger

O

FSPA

 

58

Common Indian Crow

A

FSGPA

 
 

Family Lycaenidae

     

59

Plum Judy

O

F

highly seasonal

60

Apefly

S

   

61

Common Pierrot

C

FSPA

 

62

Angled Pierrot

O

F

highly seasonal

63

Rounded/Rusty/Striped Pierrot

O

SPA

 

64

Zebra Blue

C

FSPA

 

65

Bright Babul Blue

O

FSA

 

66

Dull Babul Blue

O

FSA

 

67

African Babul Blue

C

SA

 

68

Common Hedge Blue

O

F

highly seasonal

69

Pale Grass Blue

C

SGPA

 

70

Dark Grass Blue

C

SGPA

 

71

Lesser Grass Blue

C

SGPA

 

72

Tiny Grass Blue

C

FSGPA

 

73

Lime Blue

O

PA

 

74

Small Cupid

S?

SGA

 

75

Plains Cupid

C

SGPA

 

76

Grass Jewel

C

SGA

highly seasonal

77

Gram Blue

A

FSGPA

 

78

Forget-Me-Not

O

F

 

79

Pea Blue

C

FSGPA

 

80

Dark Cerulean

O

FA

 

81

Common Cerulean

A

FPA

 

82

Common Line Blue

O

FS

 

83

Red Pierrot

C

SPA

localized

84

Common Silverline

R

FPA

 

85

Shot Silverline

S?

S

 

86

Scarce Shot Silverline

S?

S

 

87

Peacock Royal

O

FA

 

88

Indian Red Flash

O

FS

 

89

Slate Flash

O

FS

 

90

Indian Sunbeam

O

FSPA

 
 

Family Hesperiidae

     

91

Common Banded Awl

A

FSPA

 

92

Brown Awl

O

F

highly seasonal

93

Common Spotted Flat

R

F

 

94

Malabar Spotted Flat

R

F

 

95

Common Small Flat

R

SG

 

96

Spotted Small Flat

R

SG

 

97

Indian Grizzled/Indian Skipper

O

SGPA

 

98

Grass Demon

C

FP

 

99

Indian Palm Bob

O

PA

 

100

Pale Palm Dart

O

FS

 

101

Dark Palm Dart

O

FS

 

102

Rice Swift

C

FSPA

 

103

Bevan's Swift

C

FSGPA

 

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