Asad R. Rahmani

Global phylogeographic limits of Hawaii's avian malaria

The introduction of avian malaria (Plasmodium relictum) to Hawaii has provided a model system for studying the influence of exotic disease on naive host populations. Little is known, however, about the origin or the genetic variation of Hawaiis malaria and traditional classification methods have confounded attempts to place the parasite within a global ecological and evolutionary context. Using fragments of the parasite mitochondrial gene cytochrome b and the nuclear gene dihydrofolate reductase-thymidylate synthase obtained from a global survey of greater than 13 000 avian samples, we show that Hawaiis avian malaria, which can cause high mortality and is a major limiting factor for many species of native passerines, represents just one of the numerous lineages composing the morphological parasite species. The single parasite lineage detected in Hawaii exhibits a broad host distribution worldwide and is dominant on several other remote oceanic islands, including Bermuda and Moorea, French Polynesia. The rarity of this lineage in the continental New World and the restriction of closely related lineages to the Old World suggest limitations to the transmission of reproductively isolated parasite groups within the morphological species.

Catastrophic collapse of Indian white-backed Gyps bengalensis and long-billed Gyps indicus vulture populations

In 2000, we conducted a survey to quantify the declines in the populations of Gyps bengalensis and G. indicus across India since 1990–1993. Directly comparable data for the two periods were obtained from over 6000 km of road transect surveys carried out in protected areas, the regions around protected areas and linking highways across the country. An additional 5000 kmwere covered in 2000 in previously unsurveyed areas. Further data were collected fromquestionnaires circulated to ornithologists, wildlife experts and forestry officials. Massive declines in the populations of both species were apparent fromall parts of the country, and exceeded 92% overall. The extent of declines did not differ between protected areas and elsewhere. Apparently sick birds, with drooping necks, were observed in all regions, and dead adult and juvenile vultures were frequently observed. Food availability did not decline greatly over this period. The patterns of declines and the presence of sick and dead birds indicate epidemic disease as a possible

PREVALENCE AND DIVERSITY OF AVIAN HEMATOZOAN PARASITES IN ASIA: A REGIONAL SURVEY

Tissue samples from 699 birds from three regions of Asia (Myanmar, India, and South Korea) were screened for evidence of infection by avian parasites in the genera Plasmodium and Haemoproteus. Samples were collected from November 1994 to October 2004. We identified 241 infected birds (34.0%). Base-on-sequence data for the cytochrome b gene from 221 positive samples, 34 distinct lineages of Plasmodium, and 41 of Haemoproteus were detected. Parasite diversity was highest in Myanmar followed by India and South Korea. Parasite prevalence differed among regions but not among host families. There were four lineages of Plasmodium and one of Haemoproteus shared between Myanmar and India and only one lineage of Plasmodium shared between Myanmar and South Korea. No lineages were shared between India and South Korea, although an equal number of distinct lineages were recovered from each region. Migratory birds in South Korea and India originate from two different migratory flyways; therefore cross-transmission of parasite lineages may be less likely. India and Myanmar shared more host species and habitat types compared to South Korea. Comparison between low-elevation habitat in India and Myanmar showed a difference in prevalence of haematozoans.

The race to prevent the extinction of South Asian vultures

Summary Gyps vulture populations across the Indian subcontinent collapsed in the 1990s and continue to decline. Repeated population surveys showed that the rate of decline was so rapid that elevated mortality of adult birds must be a key demographic mechanism. Post mortem examination showed that the majority of dead vultures had visceral gout, due to kidney damage. The realisation that diclofenac, a non-steroidal anti-inflammatory drug potentially nephrotoxic to birds, had become a widely used veterinary medicine led to the identification of diclofenac poisoning as the cause of the decline. Surveys of diclofenac contamination of domestic ungulate carcasses, combined with vulture population modelling, show that the level of contamination is sufficient for it to be the sole cause of the decline. Testing on vultures of meloxicam, an alternative NSAID for livestock treatment, showed that it did not harm them at concentrations likely to be encountered by wild birds and would be a safe replacement for diclofenac. The manufacture of diclofenac for veterinary use has been banned, but its sale has not. Consequently, it may be some years before diclofenac is removed from the vultures’ food supply. In the meantime, captive populations of three vulture species have been established to provide sources of birds for future reintroduction programmes.

Prevalence and evolutionary relationships of haematozoan parasites in native versus introduced populations of common myna Acridotheres tristis

The success of introduced species is frequently explained by their escape from natural enemies in the introduced region. We tested the enemy release hypothesis with respect to two well studied blood parasite genera (Plasmodium and Haemoproteus) in native and six introduced populations of the common myna Acridotheres tristis. Not all comparisons of introduced populations to the native population were consistent with expectations of the enemy release hypothesis. Native populations show greater overall parasite prevalence than introduced populations, but the lower prevalence in introduced populations is driven by low prevalence in two populations on oceanic islands (Fiji and Hawaii). When these are excluded, prevalence does not differ significantly. We found a similar number of parasite lineages in native populations compared to all introduced populations. Although there is some evidence that common mynas may have carried parasite lineages from native to introduced locations, and also that introduced populations may have become infected with novel parasite lineages, it may be difficult to differentiate between parasites that are native and introduced, because malarial parasite lineages often do not show regional or host specificity.

Distribution, density, group size and conservation of the Indian gazelle or chinkara Gazella bennetti (Sykes 1831) in Rajasthan, India

Abstract The Indian gazelle or chinkara Gazella bennetti is common in the Rajasthan state of India, being present in 25 out of 26 wildlife sanctuaries and national parks. It is considered sacred by the Vishnoi community and hence large populations are found around Vishnoi villages. Three major surveys covering a large part of the state were done in 1986 and 1987, showing that in certain areas the population reached 14 per km of transect. The chinkara is a very adaptable animal and is present in the dry deciduous forests, open woodlands and sandy, dune areas within the annual rainfall range of 150–750 mm. It is generally seen in small groups of 1–3 individuals. The sex ratio was biased towards females (1:1·3).

Resource Partitioning in Three Sympatric Species of Storks in Keoladeo National Park, India

Abstract. Resource partitioning in three sympatric stork species: Black-necked Stork (Ephippiorhynchus asiaticus) Painted Stork (Mycteria leucocephala) and Asian Openbill (Anastomus oscitans) ) was studied in the Keoladeo National Park, India from October 1994 to May 1997. Little is known about their feeding success in variable water depths and habitat use. The Black-necked Stork, a solitary generalist forager, uses tactile and visual methods with a high proportion offish in the diet. The Painted Stork and Asian Openbill forage in groups of two to 100. Both Painted and Asian Openbill Storks are specialists and tactile foragers, with the former preferring fish and the latter snails (Pila spp.). Differences in prey composition were mainly due to difference in feeding behavior and water level at foraging sites. Peck rate, steps and success rate varied significantly among the three species and water level influenced feeding success. The three stork species showed variations in foraging parameters in relation to fine-scale habitat use. All stork species showed preferences for foraging habitat that differed with respect to water level, vegetation community structure and the presence of prey species. The fishing depth component of resource segregation, as described in many wading bird communities has played a major role in determining feeding success and reducing niche overlap. The findings have application to foraging habitat management and the conservation of stork species.

Running out of time? The great Indian bustard Ardeotis nigriceps—status, viability, and conservation strategies

The endemic great Indian bustard (GIB) is evolutionarily trapped between open nesting and k-selection that endangers its persistence under prevailing levels of habitat loss and hunting. A global population of about 300 birds is further fragmented into eight populations in the states of Rajasthan (shared with Pakistan), Maharashtra, Andhra Pradesh, Gujarat, Karnataka, and Madhya Pradesh in India. The largest population of 100–125 birds exists in Jaisalmer, Barmer, and Bikaner districts of Rajasthan. Remaining populations number less than 35 birds each. Prevalent GIB conservation strategies use legislation to (a) secure traditional breeding areas by declaring small Protected Areas (PA) or (b) protect vast areas with varied human land uses. The vagrant nature of GIB reduces the benevolent effect of small PAs, while large reserves alienate people by curbing legitimate subsistence rights through strict legislation. These factors along with ill-informed habitat management challenge the current PA approach, even causing local extinctions. Population viability analysis shows that GIB populations of ≤35 birds can persist only under unrealistic conditions of first year mortality ≤40%, and no human caused mortality of adult birds. Even the largest population (≥100 birds) is sensitive to additional loss of adult birds to human causes. With current levels of hunting in Pakistan, extinction is a real threat. A landscape conservation strategy using conservation/community reserve concept that includes controlled traditional land uses with GIB-friendly infrastructural development is needed. The declining rate of GIB populations calls for immediate commencement of ex situ conservation breeding programs.

Nesting Ecology of the Greater Adjutant Stork in Assam, India

Abstract The nesting ecology of the Greater Adjutant Stork (Leptoptilos dubius), the rarest stork in the world, was studied in the Brahmaputra Valley, Assam, India during 1994-97. We made a study of nine colonies in the valley during the 1994-95 nesting season, followed by a more intensive study in two subsequent nesting seasons (1995-96 and 1996-97) of two colonies at Nagaon, in central Assam. We measured the dimensions of both nest and non-nest trees, nearest distance between nest trees, and nearest house, nearest forest, nearest road, nearest water source and nearest foraging ground from each colony. All of the colonies were near human settlements. The structure of nest trees differed significantly from non-nest trees in both the overall and the intensive studies. Number of nests was highly correlated with tree height, diameter at breast height (DBH) and canopy area. About 90% of nests were built on the top of the canopy. Storks preferred to nest in compact colonies on large, widely branched trees with thin foliage cover and nearby food sources.

Understanding the patchy distribution of four-horned antelope Tetracerus quadricornis in a tropical dry deciduous forest in Central India

At the landscape level, the four-horned antelope is confined to tropical dry deciduous forests and within these, their distribution is patchy. Various factors have been proposed as determinants for their patchy distribution within landscapes, but none provided an adequate explanation. We hypothesized that availability of a constant supply of forage influenced the species distribution. We found that the four-horned antelope mainly fed on fruits and flowers, and that a total of 60% of the tree species in Panna Tiger Reserve bore fruits at different times of the year. High tree species richness in habitat patches was considered a surrogate for constant supply of forage for the four-horned antelope. Data from 547 sighting locations between 2002 and 2006 and six spatial layers were analysed using maximum entropy to produce a probability distribution model for the four-horned antelope in Panna Tiger Reserve. Our model predicted that habitat patches summing up to only 9.5% of the 543 km 2 of Panna Tiger Reserve had high probability of distribution (>0.5) of four-horned antelope. Although all variables contributed to the distribution model of the four-horned antelope, explanatory power was highest for tree species richness within habitat patches. The distribution of four-horned antelope within tropical dry deciduous forests can be treated as an indicator of high tree diversity and hence habitat quality.