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Missing numbers

  • 14/04/2007

No credible census

The ambiguity over the peafowl's status is symptomatic of a serious problem: there is no formal nationwide survey to count birds like the Common Bird Census in the uk and the Breeding Bird Census in the us. Accounts of decline in bird numbers are mostly impressionistic. Of course, there are population estimates of some flagship species. But these are based on individual research studies which are usually region-specific. Some organisations like bnhs do conduct bird census in collaboration with international groups. Some of them, like the Asian Waterfowl Census (awc), enjoy a fair degree of credibility among professional and amateur birdwatchers. But similar programmes for terrestrial birds have not taken off.

In February this year, the forest department in Coimbatore did embark on a census along these lines.The two-day exercise involved amateur birdwatchers, botanists and wildlife photographers along with department personnel. But their objective was to prepare a checklist of birds rather than count the numbers of individuals of a species. Counts such as these end up being an inventory and do not detail how many individuals of a species survive. This is critical to know how many birds are threatened and the extent of the threat.

A review article by A J Urfi and his colleagues from the University of Delhi (Current Science, Vol 89, No 12, December 2005) notes that though there is general awareness of counting techniques, population estimates provided by most surveys are not reliable. "Population estimation exercises have been undertaken for a variety of endangered birds such as the Siberian crane (Grus leucogeranus), sarus crane, great Indian bustard, lesser florican (Sypheotides indica), Bengal florican (Houbaropsis bengalensis), narcondam hornbills and vultures. But some of these studies have not employed rigorous field methods,' the paper says. There is more than a grain of truth in this contention. Surveys have rarely gone beyond impressionistic methods. For example, a 1998 survey to count water fowl in Keoladeo Ghana National Park claimed to use the

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