Endemic birds of India: ENVIS-BNHS

ENDEMIC BIRDS

"An endemic species is one that evolved in and has remained restricted to a particular place" (Quammen 1996). Rasmussen and Anderton (2005) say endemism means "Species restricted in global distribution to region". Raxworthy and Nussbaum (1996) mention that "Patterns of endemism are the product of historical events associated with speciation (e.g. time, place, and type of speciation event), as well as the responses of species to variable or changing ecological conditions (e.g. climatic change, competition)".

Very few studies have been carried out on the endemic birds of India. The preliminary information on the endemic birds in the Indian subcontinent was published by Ripley (1961), followed by Ali and Ripley (1974). Later, Grimmett et al. (1998), Kazmirzack and van Parlo (2000) have mentioned about the endemic birds in the Indian subcontinent. In addition to this, detailed study of endemic avifauna of the Andaman and Nicobar Islands was carried out by Vijayan and Sankaran (2000). In 2002, Zoological Survey of India published a book "Endemic Birds of India", covering 50 endemic bird species from India (Dasgupta et al. 2002). In this document they classified endemic birds based on the eight biogeographic zones in India.

Recently, Rasmussen and Anderton (2005) have published a book "Birds of South Asia: The Ripley Guide". In this book, they have made 198 species level changes, which include many species split within the region, split within extra-limital species and relocation of the race. They have also given comprehensive details about the endemic birds. About 218 endemic birds (see Annexure – I) have been recorded from South Asia, and the status of three species is yet to be determined. Interestingly, in India many subspecies of the birds are upgraded to the species level. Because of this upgradation 18 endemic subspecies were elevated to the species level. In this special issue of BUCEROS we have recorded 79 endemic birds in India. This means India comprises almost 36% of the endemic birds of South Asia.

Here we describe the endemic, and some near-endemic birds of India. Bird diversity tends to change with various environmental as well as spatio-temporal factors. The status of certain species could not be determined due to unavailability of authentic information. The Large-billed Reed Warbler Acrocephalus orinus is classic example. It was known to science only from one specimen collected from Himachal Pradesh in India. It was considered as an endemic because the bird had relatively round wings (Ali and Ripley 1974). However, recently it was found in Thailand (Round et al. 2006). Similarly, the recently described Bugun Liochichla Liocichla bugunorum (Athreya 2006) is not included in this issue as no information is available on its distribution and status.

Criteria for the endemism

To determine the endemic bird status we have followed four criteria:

1. Presence of the species only within Indian limits.

2. Majority of the population of the bird should be within India

3. Island endemics - The birds which are restricted to the Andaman and Nicobar Islands are treated separately. Some of the islands from the Andaman group politically belong to Myanmar; however, biogeographically they are a part of the Andaman group of island; especially the Table Island and the Coco Island. So, the bird species found on these islands are treated as endemic to India.

4 Vagrant and dubious records - Few vagrant and dubious records of birds from neighbouring countries such as Pakistan and Nepal are treated as endemic to India as there are no authentic records of these birds from those countries. Along with this, we have also included some species which are almost extinct in these neighbouring countries, but present in India.

Endemic Bird Area (EBA)

An Endemic Bird Area is defined as an area which encompasses the overlapping breeding ranges of restricted range bird species, such that the complete ranges of two or more restricted species are entirely included within the boundary of the EBA. This does not neccessarily mean

that the complete ranges of all of an EBA’s restricted-range species are entirely included within the boundary of that single EBA, as some species may be shared between EBA’s (Stattersfield et. al. 1998). For details on Endemic Bird Areas, please refer to (Stattersfield et. al. 1998).

There are twelve Endemic Bird Areas (seven EBA and five secondary areas) occur in India. In this BUCEROS we have restricted ourselves to eight Endemic Bird Areas (five EBA and three secondary areas) such as Andaman Islands, Assam plains, Central Indian forests (secondary area), Eastern Andhra Pradesh (secondary area), Nicobar Islands, Southern Deccan plateau (secondary area), Western Ghats, Western Himalaya as the endemic avifauna of the remaining four areas occurs in the neighbouring countries too.

Conservation

Restricted-range or endemic bird species with limited geographical ranges and small population sizes are of great conservation concern (Stattersfield et al. 1998) as they are particularly vulnerable to extinction from stochastic processes (Wright and Hubble 1983). Of 79 endemic birds found in India, 18 species are globally threatened (Table. 1). Of these 79, 23 % species are globally threatened, three percent are data deficient, 19 % are near threatened, 34% are least concern and status of 20 % species is not confirmed. Therefore, we have a great responsibility to safeguard and conserve our endemic birds. List of the species which require revision is given at the end of the Annexure - I.

Table.1 Status of the Endemic Birds of India

Sr. No Criteria Number

1 Critically Endangered 3

2 Endangered 1

3 Vulnerable 14

4 Data Deficient 3

5 Near Threatened 15

6 Least Concern 27

7 Revision Required 16

Total 79

Abbreviations used in the text:

Synopsis No. – A synopsis of the birds of India and Pakistan together with those of Nepal, Sikkim, Bhutan and Ceylon. Ripley, S. D. (1961)

HBI – Handbook of the Birds of India and Pakistan. Compact Edition. Vol. 1-10. Ali, S. A. and S. D. Ripley (1983)

BIS – Birds of the Indian Subcontinent. Grimmet, R., C. Inskipp and T. Inskipp (1998)

TBOI – The Birds of India, Sri Lanka, Pakistan, Bhutan, Bangladesh and the Maldives. Kazmierczak, K. and van Perlo, B. (2000)

Reference:

Jathar, G.S. & A.R. Rahmani, (2006). Endemic Birds of India. Buceros Vol. 11 (2&3): 53 pp.

Note

As we are not qualified avian taxonomists, and we do not have all the original literature, we have not made any attempt to discuss the merit and demerit of putting a particular taxa as a species or subspecies, or under a particular genus. In this special issue of the BUCEROS, we have mentioned in chronological order how different authors have placed a particular species. This document is based on the taxonomy suggested by Rasmussen and Anderton (2005).