Is floating and wading, a common behavior of Indian pond heron (Ardeola grayii)?

Abstract

The Indian pond heron or Paddy bird (Ardeola grayii) is a small heron belonging to the family Ardeidae. Ponds, streams, marshy wetlands are the major feeding habitat of the Indian pond heron and usually they feed at the edges of water bodies. While conducting behavioural studies of wetland birds in Kole wetlands of Thrissur, Kerala (10° 20' & 10° 40' N and 75° 58' & 76° 11' E), on 8th August 2016, an Indian pond heron was seen floating and wading in running water (water depth at 110 cm) from Pullazhi Kole (10° 20' 46.27” & 76° 9' 17” E), Thrissur. A mixed flock of Indian pond heron, Kingfishers and Cormorants were seen standing on the edge of the canal, suddenly when the motor pump started to dewater the canal, an Indian pond heron jumped into the water and was seen floating along the water and wading, without the support of any floating vegetation. It continued the floating for about 2.7 minutes, till it touched the shutter and flew away. The increased population during the breeding season and reduced foraging areas due to decreased rainfall lead to interspecific competition. Both the Little cormorant and the Indian pond heron being piscivorous birds, several instants of competition for foraging area were observed. As fishes in the canal move along with the flowing water and congregate near the net placed near the shutter, it would be easy to wade and catch the fish. This may be the reason behind such a floating and wading behaviour of the Indian pond heron.