当前世界环境

Introduction

The ornithological history of Delhi, the capital of India, is relatively old. The foremost inventory of bird species in Delhi is made by Basil-Edwardes (1926)¹who reported 204 species and sub-species. Thereafter there are many ornithologists^2-7who worked on similar lines. Apart from this, Kalpavriksh (1991)⁸recorded 444 species in Delhi and its surrounding areas and Satya (1993)⁹revealed 101 species remarkably affected both positively and negatively by urbanization in Delhi.

There are huge lands under university campuses supporting half the biodiversity of urban biota.¹⁰But the conservationists till now have ignored these areas and have not utilized these areas for conservation purposes. One such area is the Jawaharlal Nehru University (JNU) campus situated in the southern part of Delhi, (Lat 28°32'15.42"N, Long 77° 9'52.24"E). It is built on the Aravali Hill Ranges which extends upto Gujarat. The campus area encompasses around 400 ha. The unique feature of the campus are the vast areas of undisturbed ridge ecosystems which it still holds. These are connected with the adjoining Sanjay Van forest which again represents the ridge ecosystem. A previous study in ridge systems alone by Gaston (1978)¹¹revealed 167 bird species. As Delhi comes under the subtropical belt, it experiences a semiarid climate. The temperature varies from 45ºC in summer to 1ºC in winter.¹²The average rainfall is around 611 mm.¹²The campus has good areas of dense thorny deciduous species and fleshy evergreens. Though the vegetation is mainly xerophytic,¹³it does support a diverse variety of fauna. In addition to the ridge forest vegetation, the campus represents different habitats like small check-dams, gardens with ornamental shrubs, avenue trees along the roadsides etc. which are abode for the avifauna.

Though there have been many bird watching activities in the campus, none of data is published. This will be the first published inventory of the bird species found in the JNU campus. This inventory will not only bring out the baseline information on the bird species diversity supported by the campus, but also highlight about their presence and conservation status. This data can be further used by the campus authorities and city planners for planning developmental activities. This information will also come in handy to the conservationists for creating awareness for bird conservation in the campus.

Materials and Methods

This work is an effort of compilation of observations done from 2013 to 2016 i.e. three years. Line transects were laid in different habitats of the campus area such that data representing all the habitats present in the survey area could be collected. The survey was carried out from 06:00 hrs to 10:00 during non rainy and non windy days. Survey was done twice a week in each season to get the data of seasonal variation. The birds feeding habits were also noted. Observations were done using a 8x42 binocular (Bushnell). Birds were identified using Grimmett et al. (1999)¹⁴and Ali and Ripley (1995).¹⁵Birds were classified according to their presence status (season-wise) as residents (R), Passage migrants (PM), Summer visitors (SV) or Winter visitors (WV), Vagrant (VA) (Table 1). The conservation status of the birds recorded are also mentioned in Table 1. Further, they were also classified according to their feeding habits into different guilds like Granivorous (GR), Frugivorous (FR), Omnivorous (O), Insectivorous (I), Carnivorous (C), Nectarivorous (NI), Piscivorous (PI), Herbivorous (H) (Table 1).

Table 1: Bird species sighted at JNU campus, their IUCN conservation status, visiting status and feeding guild

IUCN Status: LC-Least Concern, NT-Near Threatened, Visiting status: R-Resident, WV-Winter Visitor, SV-Summer Visitor, PM-Passage Migrant, VA-Vagrant, Feeding guild: GR-Granivorous, FR-Frugivorous, O-Omnivorous, I-Insectivorous, C-Carnivorous, NI-Nectarivorous, PI-Piscivorous, H-Herbivorous

Results

A total of 114 bird species belonging to 19 orders and 52 families were observed in three years duration (Table 1). Among the total birds reported, 79 species (69%) were residents, 26 species (23%) were winter visitors, 4 species (4%) were passage migrants, 3 species (3%) were summer visitors and 2 species (1%) were vagrant (Fig. 1).

Figure 1: Visiting status of bird species recorded in JNU campus Click here to View figure

The study reported birds with diverse food habits. The highest observed bird species were insectivorous (47 species, 41%), followed by omnivorous (33 species, 29%), carnivorous (14 species, 12%), frugivorous (7 species, 6%), gramnivorous (6 species, 5%), herbivorous (4 species, 4%), piscivorous (2 species, 2%) and the least were nectarivorous (1 species, 1%) (Fig. 2). According to the IUCN status, 3 species (3%) were near threatened and the rest 111 species (97%) were least concern (Fig. 3).

Delhi is reported to support 434 avifaunal species belonging to 17 orders and 59 families.¹⁶Thus, the campus accounts for 26% species, 89% orders and 88% families of birds of Delhi. The present study recorded a little lower bird species than that recorded by (Prakash and Manasvini, 2013)¹⁷(132 species) in a similar habitat of the southern ridge of Delhi. The bird species recorded in the JNU campus is comparatively more than that reported in areas with similar vegetation structure and composition like Aravali Hill (72 species),¹⁸New campus of J.N.V. University, Jodhpur, Rajasthan (68 species).¹⁹This high species diversity is because of ample number of thorny trees and shrubs which attract large numbers of birds²⁰. The species likeAcacia leucophloea, Albizzia lebbeck, A. mollis, Alstonia scholaris, Azadirachta indica, Bauhinia variegata, Bombax ceiba, Caryota urens, Cassia fistula, C. siamea, Ficus religiosa, F. elastica, Leucaena leucocephala, Mangifera indica, Prosopis juliflora, Syzygium cumini等常见的校园。

The fruits and flowers of shrubs likeAgave americana, Carrisa spinarum, Hibiscus rosa sinensis, Lantana camara, Zizyphus nummulariasupport diverse varieties of birds. This is also the reason for such high diversity of birds in the campus. Three near threatened bird species, namelyPsittacula eupatria, Threskiornis melanocephalusandMycteria leucocephalaare also recorded from the study area. The former two species are resident and are found frequently and abundantly in the area, whereas the later species is found only during the winter season but at a lower frequency rate. The species is mainly restricted only to the water reservoir in Paschimabad. This is a good indicator as the reservoir is near to the residential quarters of JNU, indicating that this species is human tolerant. Similarly, near threatened species such asBuceros bicornisandPsittacula eupatriawere sighted in tea estates of Assam²¹andPloceus philippinuswas sighted in the homegardens of Assam.²²Both these sites are closely associated with human habitation and have high human activity in them, but still have good sightings of species of conservation importance. The study area not only supports the least concerned species, but also highly endangered species. Not only this, the campus also has recorded resident (79 species), migratory (33 species) and vagrant (2 species) species which indicates good and healthy ecosystem.¹⁷Thus, this study depicts the importance of semi urban habitats in biodiversity conservation. Another reason for high bird diversity in the JNU campus may be because the human disturbance and habitat modification is less in this area as compared to the other areas of the Delhi region. In addition to this, small water bodies are found in and around the ridge ecosystems which makes the area more suitable for different species of birds to survive and thrive on.

Through this paper, it can be highlighted that the campus area of JNU is still preserving the natural ecosystem which hardly can be seen in other ridge areas of Delhi as most of them are under immense anthropogenic pressure. Being an educational institute, there is a lot of scope to improve and conserve this highly biodiverse area through awareness programmes and institutional policies. It can therefore be concluded that JNU campus is a role model for conservation of fast vanishing ridge ecosystems. It can also be stated that these ecosystems are very crucial for the survival and continuity of the avifaunal diversity in the campus. Similar kind of studies can be taken up in other university campuses in and around Delhi. This will help in preparing a base line data and further help in conservation.

Figure 2: Classification of bird species recorded in JNU campus according to their feeding guilds Click here to View figure

Figure 3: IUCN status of bird species recorded in JNU campus Click here to View figure

Acknowledgement

我们感谢环境学院的院长Sciences and administration of Jawaharlal Nehru University, New Delhi for their administrative support. The authors are thankful to University Grants Commission for awarding the Basic Sciences Research (BSR) Meritorious Student Fellowship which provided the financial support to carry out the fieldwork.

References

1. Basil-Edwardes, S., A contribution to the ornithology of Delhi.Journal of Bombay Natural History Society, 31: 261-273, 567-578 (1926)
2. Frome, N. F., The birds of Delhi and district.ibid,47: 277-300, 751-753 (1947)
3. Hutson, H. P. W.,The birds about Delhi.Delhi Bird Watching Society (1954)
4. Donahue, J. P., Notes on a collection of Indian birds, mostly from Delhi.ibid, 64: 410-429 (1967)
5. Abdulali, H., & Panday, ,清单的鸟类德里,阿格拉和Bharatpur.New Dehli (1978)
6. Urfi, A. J., Wetlands of ornithological significance in the Delhi region.OBC Bulletin,22: 38-41 (1995)
7. Gaur, S., Bird Haven (in a drain!).Srishti,2(1): 34-38 (1995)
8. Kalpavriksh,What's that bird? A guide to birdwatching, with special reference to Delhi.Kalpavriksh, Munirka, New Delhi, pp. 1-93 (1991)
9. Satya, S. C., Effect of Urbanization on Avifaunal Diversity in Delhi. (Sc. Thesis). Dept. of Environmental Biology, University of Delhi, pp. 1-85 (unpublished) (1993)
10. Patvarthan, A., Nalavade, S., Saharsabuddhe & Utkarsh G.,Urban wildlife from Nero's fiddle to Noah's arch.RANWA, Pune (2000)
11. Gaston, A. J., The seasonal occurrence of Birds on the New Delhi Ridge.Journal of Bombay Natural History Society,75(1): 115-128 (1978)
12. CPCB (Central Pollution Control Board),Air Quality Status and Trends in India. New Delhi, pages 163, NAAQMS/14/1999–2000 (2000)
13. Champion, H. G., & Seth, S. K.,A revised survey of the forest types of India. Goverment of India Press (1968)
14. Grimmett, R., Inskipp, C. & Inskipp, T.,Birds of the Indian subcontinent.牛津大学出版社,新德里,页344 (1999)
15. Ali, S., & Ripley S. D.,A Pictorial Guide to the Birds of the Indian Subcontinent.2^ndEdition (Updated). B.N.H.S. and Oxford University Press, Mumbai, pp 183 (1995)
16. Tak, P. C., & Sati, J. P.,AVES. State Fauna Series 6: Fauna of Delhi, Zoological Survey of India, 699-821 (1997)
17. Prakash, S., & Manasvini, Urban avifaunal diversity: an indicator of anthropogenic pressures in southern ridge of Delhi.Advances in Bioresearch,4(2): 135-144 (2013)
18. Devarshi, D., & Trigunayat, M. M., Checklist of the birds of Mount Abu (Rajasthan).Pavo, 27: 59-63 (1989)Dookia, S., A checklist of birds of New Campus, J.N.V. University, Jodhpur, Rajasthan.Zoo's Print Journal, 17(9): 883-885 (2002)
    CrossRef
19. Jain, N. K., Patel., S. N., & Patel., M. V., Birds of Gujarat University Campus, Ahmedabad.Zoo's Print Journal, 20(12): 2111-2113 (2005)
    CrossRef
20. Yashmita-Ulman, Kumar, A., & Sharma, , Agroforestry systems as habitat for avian species: assessing its role in conservation.Proceeding of Zoological Society, DOI: 10.1007/s12595-016-0198-3 (2016)
    CrossRef
21. Yashmita-Ulman, Kumar, A., & Sharma, M., Traditional home garden agroforestry systems: habitat for conservation of Baya WeaverPloceus philippinus(Passeriformes: Ploceidae) in Assam, India.Journal of Threatened Taxa, 9(4): 10076–10083 (2017)
    CrossRef
22. Yashmita-Ulman, Kumar, A., & Sharma, M., Traditional home garden agroforestry systems: habitat for conservation of Baya Weaver Ploceus philippinus (Passeriformes: Ploceidae) in Assam, India. Journal of Threatened Taxa, 9(4): 10076–10083 (2017)