The mallard and Eurasian teal are the forerunners of migratory birds that have landed in some of the province's reservoirs, IRNA quoted Mehdi Allahpour as saying on Monday.
In January and February bird migration reaches its peak in the province, because they migrate to warmer southern areas to spend the winter, he noted.
Mallard, cormorant, bitterns, Eurasian teal, and heron are among the aquatic species that come to this province from the cold regions of Siberia.
Every year, with the onset of the cold season, different areas of the province such as rivers, reservoirs, and dams host 40 species of migratory birds, he concluded.
Annual census for migratory birds in Iran begins in the middle of the Iranian calendar month of Dey (December 22-January 20) and ends in the middle of the month of Bahman (January 21-February 19), through which Iran hosts rare species of migratory birds heading from north to the southern countries due to reduced seasonal temperatures and food availability.
In December 2018, Majid Kharrazian-Moqaddam, head of aquatic animals and wildlife affairs at the Department of Environment said that the total population of migratory birds took a flight to spend the cold season in the country increased by 26.5 percent last winter compared to a year earlier, with increased rainfall averages and accordingly wetlands being filled with water.
In North Khorasan, there are 65 species of mammals out of 197 species in the country and 141 species of birds out of 532 species in the country, 68 reptiles out of 228 species in the country, four species of amphibians out of 20 species, and 8 species of fish and aquatic animals out of 160 aquatic species living in the country, some of which, such as cheetahs, saker falcon, Bustards, Caspian snowcock and Egyptian vultures, are in the International Union for Conservation of Nature (IUCN) in critical and endangered categories.