Kingdom Animalia
Click to hear the call  Click to watch the video
Phylum Chordata
Class Aves
Order Acciptriformes
Family Acciptridae
Genus Circus
Species aeruginosus
Classification Linnaeus, 1758
Common namee marsh harrier
Size 48 - 55 centimeters
Wing Span 110 - 125 centimeters
Male weight 400 - 650 grams
Female weight 500 - 800 grams

Geographic Range Europe and Northern Asia.
Physical Characteristics the male can be recognized thanks to its tricolour plumage: dark brown feathers, dark red coat, and ash grey tail and wings. The female and the young are uniform brown, the upper part of the female's head is cream-coloured as the border at the joint of the wings. The band of face feathers is characteristc: it is similar to that of the owl and it covers the unusually big ear openings (which are an adaptation needed to locate prey among high grass thanks to its rustle and its squeaking).
Call it is relatively quiet. Only the male whistles when there is a wedding parade or when he is flying, or if he is giving prey to the female.
Behaviour it is predacious, therefore it searches the territory looking for its favourite prey: rodents and most of all chicks of waterfowl as coots or ducks. During courtship, the male does extraordinary acrobatics over the nest and over the surrounding area. During nesting, the male goes hunting and when he brings the prey back he warns the female with a characteristic whistle. The female then reaches the male and, flying, puts herself under him, afterwards she turns bringing up her paws. The male leaves the prey and the female takes it with her paws. The exchange of prey takes place this way, and the synchronization of the movements of the couple is impressive.
Habitat it can be found in marshes and in beds of reeds. During the migration it is rarely seen in open, dry pasture lands and it mainly follows littoral and river valleys, even if it sometimes has to cross dry areas. Within its hunting areas it spends most of time flying.
Flight its flight is slow. It performs long exploration flights at low flying height over the fields, rarely flapping its wings, keeping them well-open over its back. It flies higher than other hawks, usually at 35- 30 meters from the ground.
Food habits it feeds on small water mammals, the chicks and the eggs of water hens, coots, and other waterfowls; frogs, reptiles, insects, ill, injured or dead animals.
Migration northern populations and most of the souther ones are migratory. Migration towards Western Europe starts at the half of August with the young birds born during the year, followed by the adult ones in September- October. The males migrate later than the females and the young and reach wintering places afterwards. The rate and extension of migration depends on the place of origin, in fact the birds coming from northern areas leave before, and they move faster than the birds coming from southern Europe and that can spend most of the winter near their mating area. Southern migration from Europe follows a very precise route, through Gibraltar and the Bosporus, and they rarely cross large bodies of water. During migration they can fly so high that they can pass over mountain chains, even if they usually prefer to fly low. Migration towards North starts in February and March and usually crosses the Mediterranean Sea. They usually migrate alone or in small groups, not in big flocks; but when they alight they become more gregarious than usual, forming groups of more than 300 individuals. The birds reach their reproduction areas from late March on, at the latest on the first days of May in the most northern zones of the areale. In Italy they are migratory and wintering; locally sedentary.
Nidification it takes about 10 days for the female to build a big flat nest made up of hurdles and grass, well hidden in the thick vegetation of the bed of reeds or in the shallow water thick vegetation. Both parents add stuff to the nest while taking care of the chicks. The laying of the eggs takes place from April to June, the greenish eggs can be 4 or 5. The female incubates an egg at a time, usually starting from the first, for 31-38 days. For the first week the chicks are hatched by the female, which feeds them with her beak, but afterwards they feed by themselves in the nest, even with a certain ferocity: if the food isn’t enough, the biggest chicks kill and feed on the smallest. When the young are grown the female helps the male in the hunting and if the male gets killed she can succeed in breeding a clutch by herself. After a month the young scatter in the surrounding vegetation and they cover with feathers after 35-40 days. The male leaves the nest for good to migrate little after, but he usually stays with the female for another 15-25 days.
Status in the lagoon it can be found in salt marshes and in the fragmitetum and sometimes in some wet areas of the hinterland, as the former caves of clay in Marcon. During winter the sedentary and nest-building population is increased by the wintering individuals that reach the Lagoon from Central Europe, Scandinavia and Russia.

References The Hawk Conservancy and Country Park - England
Museo Zoologico "La Specola" di Firenze
I censimenti degli uccelli svernanti in Provincia di Venezia - a cura di M. Bon e G. Cherubini - Provincia di Venezia, Assessorato Caccia e Pesca.
Web References http://www.hawk-conservancy.org
Source of the photo http://www.hawk-conservancy.org/priors/marsharr.htm
Source of the call http://www.oiseaux.net/
Source of the video http://www.rspb.org.uk/

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