Watervogels

The number of nesting wading birds in South Florida, a key measure of Everglades health, sunk to a decade-long low last year, according to a South Florida Water Management District report released this week, the latest in a 22-year tally. Just over 26,000 nesting birds were counted across the Everglades and in Lake Okeechobee last year, well below the 10-year annual average of about 42,000.

Pesticide residue from rice polders and nutrient discharge from urban settlements are aggravating the pollution of Vembanad Lake, playing havoc with the fragile wetland ecosystem and jeopardising its tourism potential. A study conducted by the Regional Agricultural Research Station (RARS), Kumarakom, under Kerala Agricultural University (KAU), has reported a high level of eutrophication of the lake, a Ramsar site and the hub of backwater tourism in Kerala. Data collected by the environmental surveillance centre at RARS indicate that the organic pollution of the lake is getting worse.

Over the last 14 years, waterbirds in Myanmar's Irrawddy River declined by 60% to 90% depending on the species. Scientists working for Fauna & Flora International (FFI) and Manfred Hermsen Foundation have repeated an ornithology survey of the Myitkyina to Mandalay stretch of the Irrawaddy River last carried out in 2003. They found that many waterbirds have declined sharply. More than 20,000 waterbirds (61 species) were recorded along the river, with small pratincole (Glareola lactea) and ruddy shelduck (Tadorna ferruginea) the most numerous recorded.

The mighty Brahmaputra and its tributaries serve as the winter visiting ground to many migratory birds. From the marshes of Kaziranga to the forests of Eaglenest in western Arunachal and further up to the alpine areas of Arunachal -- one come across more than 750 species of birds that includes most of the winter visitors. Assam, along with the other six northeastern states, shares a common migration route for many of the avifauna that flies over Bhutan, Tibet, China, Myanmar and Bangladesh.

Fewer migratory birds visited the Naujan Lake National Park in Naujan town in Oriental Mindoro province last month, a recent bird census showed. From 10,821 birds recorded in 2016, only 6,932 from 36 species were recorded during the survey held last month by the NLNP-Asian Waterbird Census (AWC) team. “The cause of this decline is not yet clear but it could be due to several factors, including the unfavorable weather conditions over the past weeks,” Don Geoff Tabaranza, project development and resource manager of the Mindoro Biodiversity Conservation Foundation Inc.

The exposure effects of two endocrine disrupting pesticides (EDPs), mancozeb/MCZ and imidacloprid/IMI of the group dithiocarbamate and neonicotinoid respectively, on reproductive behaviors and secondary sexual characters have been studied in a seasonally breeding wildlife bird, red munia (Amandava amandava). Adult male birds were exposed to both the pesticides individually (0.25% LD50 of each) as well as co-exposed (MIX-I: 0.25% LD50 of each and MIX-II: 0.5% LD50 of each) through food for 30 d in preparatory (July–August) and breeding (September–October) phase of reproductive cycle.