Meerut, Jan 24 : Shrinking wetlands have kept migratory birds away from Hastinapur Wildlife Sanctuary in Uttar Pradesh this year. According to the Asian Waterbird Census (AWC) 2023, it recorded a decrease in species diversity from 45 to 38 compared to last year and a fall in the number of water birds from 1,521 in 2022 to 931 this year. The 38 species include 20 resident species, 18 winter migratory species and five species of IUCN (International Union for Conservation of Nature) red-listed threatened birds. Some of the winter migratory water bird species recorded this year include those that migrate from central Asia like Greylag Geese, Barheaded Geese and Ruddy Shelduck among others. Elaborating on the reason for the sharp decline, AWC state coordinator, Wetlands International, T.K. Roy said: "Unexpected rainfall in the months of October and November last year revived several dried wetlands, especially seasonal marshlands on the Ganga floodplains which attracted a good number of long-distance winter migratory birds, especially ducks, geese and waders as recorded till December 2022. "However, this year, most winged guests did not turn up as the revived wetlands largely dried up and existing bigger wetlands are fully choked by water hyacinth, leaving little space for the birds to thrive." The census, which started from January 7 and concluded on January 22, was carried out with active participation of the department of zoology faculty and student volunteers' team from Meerut's Chaudhary Charan Singh University, along with Wetlands International, a not-for-profit global organisation based in the Netherlands, which works to sustain and restore wetlands and their resources for people and biodiversity. /IANS