Tag: all of Circus

Nest-site selection by Marsh Harrier (Circus aeruginosus) in the shore belt of Helophytes on large lakes

Western Marsh Harrier (Circus aeruginosus) Science Article 2 abstract Nest-site selection by Marsh Harrier (Circus aeruginosus) was investigated on Lakes Meteliaiand Obelija in 1983n1986 and Lake fialtytis in 1984n1986 in southern Lithuania. Fifty five breedingpairs were detected and 49 nests (89.1%) were found. With regard to the potential breeding habitat,Lakes Meteliai and fialtytis represented extreme […]

The effect of predation by Marsh Harriers Circus aeruginosus on the survival of ducklings and game bird chicks.

Western Marsh Harrier (Circus aeruginosus) Science Article 4 abstract The level of predation by a pair of Marsh Harriers Circus aeruginosus on ducklings and gamebird chicks was calculated from observations of hunting ranges, feeding rates and diet, and estimates of the availability of prey during the breeding season. The harriers took 22% of the Pheasant […]

Reproduction of the Marsh Harrier Circus aeruginosus in recent land reclamations in The Netherlands.

Western Marsh Harrier (Circus aeruginosus) Science Article 6 abstract We studied temporal variation in reproductive performance of Marsh Harriers Circus aeruginosus in two land reclamations in The Netherlands, i.e. South Flevoland and the Lauwersmeerpolder, embanked in 1968 and 1969 respectively. The number of breeding pairs in Flevoland rapidly increased to a maximum of 350 pairs […]

Predation by a Marsh Harrier Circusaeruginosus on Yellow-legged GullLarus michahellis nests

Western Marsh Harrier (Circus aeruginosus) Science Article 8 abstract This note reports a case of predation by an adult female Marsh Harrier Circus aeruginosus onthree nests of Yellow-legged Gulls Larus michahellis at the Ebro Delta. The predation wasobserved on 4 April 2002 on one of the dykes that separate the saltpan-heaters of La Trinitat(Punta de […]

Factors influencing nest material selection in Marsh Harrier (Circus aeruginosus)

Western Marsh Harrier (Circus aeruginosus) Science Article 3 abstract Marsh Harrier used at least 30 plant species from natural and cultural landscapes andhabitats for nest building on Lakes Meteliai, Obelija and fialtytis (southern Lithuania). Helophytesdominated among plant species, particularly reeds, though the share of terrestrial plants (especially ofrobust agrolandscape plants) sometimes was very significant. The […]

Changes in the frequency of prospecting fly-overs by Marsh Harriers Circus aeruginosus in relation to short-term fluctuations in dabbling duck abundance

Western Marsh Harrier (Circus aeruginosus) Science Article 7 abstract Wintering waterfowl gathering in large flocks during the day may be attractive to avian predators in a way similar to that of bird colonies. The response of Marsh Harriers to changes in dabbling duck abundance was monitored on four freshwater sites in the marshes of western […]

New material supplies in the Marsh Harrier Circus aeruginosus sexual roles daily and seasonal activity patterns and rainfall influence

Western Marsh Harrier (Circus aeruginosus) Science Article 5 abstract Nest maintenance is an important part of parental care for the Marsh Harrier Circus aeruginosus throughout the entire breeding period. Nest material supply trips are mainly carried out by the female as the male only contributes during incubation and the early nestling period. The trips rate […]

Main migratory direction of Marsh HarrierCircus aeruginosus: an analysis of recovery data ofspecimens ringed in Latvia from 1925 to 2004

Western Marsh Harrier (Circus aeruginosus) Science Article 1 abstract Th is paper describes the main migratory directions of the Latvian Marsh Harrier Circus aeruginosuspopulation and provides an overview of recovery data. Th e study was based on analysis of recoverydata of Marsh Harrier that were ringed in Latvia from 1925 to 2004 and subsequently recovered.In […]

Food-niche differentiation in sympatric Hen Circus cyaneus and Montagu’s Harriers Circus pygargus

Northern Harrier (Circus cyaneus) Science Article 4 abstract Hen Harriers Circus cyaneus and Montagu’s Harriers Circus pygargus are medium-sized raptors that differ in size (Hen Harrier being slightly bigger than Montagu’s Harrier) and breeding system (Montagu’s Harriers are semi-colonial and Hen Harriers defend nesting-hunting territories). In contrast, the diets of the two species when in […]

Habitat use by Hen Harriers Circus cyaneus on Orkney: implications of land-use change for this declining population

Northern Harrier (Circus cyaneus) Science Article 3 abstract The use of habitats by hunting Hen Harriers Circus cyaneus just prior to the settlement period was investigated on Orkney, where numbers have declined by 70% over the last 20 years. Both males and females hunted over areas that were closer to subsequent breeding territories. Neither sex […]