Podoces
Volume:8 Issue: 2, 2013

Although research activities on tracking the migration routes of birds are increasing all over the world, this kind of research is very limited in Iran. To promote this activity, this papers aims to review all available information on the migration routes of birds in Iran derived from radiotracking techniques. To concentrate more on bird groups, we have focused on waterbirds and raptors, and exclude information on the Asian Houbara Bustard. Five species of waterbirds and seven species of raptors have been tracked entering or crossing Iran.

The Brahmaputra is one of the significant river ecosystems of Assam. A brief avifaunal survey was conducted alongthe Brahmaputra River, Assam, during February and March 2012. A total of 220 species belonging to 47 families were recorded. Twentyspecies were globally threatened (4 Critically Endangered, 2 Endangered, 6 Vulnerable and 8 Near Threatened) including Slender-billed Vulture Gyps tenuirostris, Whitebacked Vulture Gyps bengalensis, White-winged Duck Asarcornis scutulata, Baer’s Pochard Aythy abaeri, Lesser White-fronted Goose Anser erythropus, Bengal Florican Houbaropsis bengalensis, Greater Adjutant- Stork Leptoptilos dubius, Spot-billed Pelican Pelecanus philippensis, Black-headed Ibis Threskiornis melanocephalus, Lesser Kestrel Falco naumanni, Black-necked Stork Ephippiorhynchus asiaticus, Oriental Darter Anhinga melanogaster and Grey-headed Fish-Eagle Ichthyophaga ichthyaetus. All species of birds observed during the survey were recorded and some significant records are discussed. Nine of the 47 families were represented by more than seven species (8 to 30), 21 by three to six species and 17 by one or two species. Suggestionsare made forthe introduction of control measures to regulate the intensive fishing activities and agricultural practices of local people on islets in the river. Providing them withalternative sustainable livelihoods may help to sustain the river ecosystem.

We examined concentrations of mercury (Hg) in the feathers of 72 waterbirds belonging to six species. Mercury concentrations (μg g-1 dry weight) in the feathers of waterbirds ranged from 0.11 ± 0.03 (Garganey, Anas querquedula) to 0.60 ± 0.15 (Ardea purpurea, Purple Heron). Significant differences in Hg concentrations between the six studied species were observed (ANOVA, p < 0.01); Purple Heron ≥ Common Teal Anas crecca ≥ Northern Shoveler Anas clypeata = Common Coot Fulica atra > Greater Flamingo Phoenicopterus roseus = Garganey. Significant differences in the mean Hg concentrations were found among these species as a function of the feeding method and the trophic level (p < 0.001). Mercury concentration in the feathers of waterbirds in the present study were below the thresholds reported to impair reproduction.