A study has unveiled that three UK breeding wagtail species are declining. A report of latest Breeding Bird Survey (BBS) has stated that reason behind the decline is still not clear.

Yellow Wagtail, small passerine in the wagtail family Motacillidae, is one of the three wagtail species spotted in the UK that is facing long-term decline. Apart from that, Grey Wagtail, which looks similar to the yellow wagtail, and Pied Wagtail are two other wagtail species that remain in the UK over the winter.

According to researchers, Yellow Wagtail and Pied do not breed anywhere in the world other than the UK.

Breeding Bird Survey's report has stated that the population of Yellow Wagtails has dropped by 43% in the years from 1995 to 2012. Change in agricultural practices is considered to be the reason behind decline of species. Researchers have said that as the species is long-distance migrant the overseas conditions could also be the reason for decline.

Grey Wagtail has been on the Amber list of Birds of Conservation Concern since 2002. Grey Wagtail has declined by 32% and Pied Wagtail has shown decline of 11%.

The researchers said that both Grey and Pied Wagtail have shown rapid decline along canals and rivers. According to Waterways Breeding Bird Survey (WBBS), which concentrates on rivers, the Pied Wagtails have seen steeper decline in the survey than the BBS trends that cover all habitation.

BBS Organiser at the British Trust for Ornithology, Sarah Harris, said, "I find it fascinating that three seemingly similar birds, the Yellow, Grey and Pied Wagtail can lead such different lives and face such a variety of challenges".

She also said that Yellow and Pied Wagtails are largely confined to UK. The changes in the bird population are of global conservation significance.