Marsh Harriers like most raptors come in for their fair share of mobbing by potential prey species, usually birds particularly Carrion Crows but they also mob species that are potential predators of their nests and young mainly Bitterns, Red Foxes, Otters and Mink though the actual source of the mobbing is often invisible when hidden in a dense reedbed. Below are some shots of Marsh Harriers mobbing and being mobbed.
A young male Marsh Harrier, probably 3cy, watching then mobbing a Red Fox on a causeway near its nest site in an adjacent reedbed.
Carrion Crows and other corvids are the species usually seen harassing Marsh Harriers but potential prey species will mob birds particularly those individuals that are seen as a low threat; here a flock of Starlings shadows a juvenile Marsh Harrier returning to its reedbed roost site.
Carrion Crows area a regular source of annoyance for Marsh Harriers particularly when the two species breed in close proximity. Male Marsh Harriers are not that much bigger than Carrion Crows but they are much more agile and can suddenly turn on a sixpence and reverse the attack chasing the crows but I have yet to actually see any physical contact between the two species. The images below show the contortions that harriers produce in their confrontations with Carrion crows.
