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 […]
Category: Accipitriformes
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 […]
POSSIBLE SPECIALIZATION FOR HUMMINGBIRD-HUNTING IN THE TINY HAWK
Tiny Hawk (Accipiter superciliosus) Science Article 1 abstract This paper describes the hunting tactics of the Tiny Hawk, Accipiter superciliosusfontanieri, in a Costa Rican rain forest, where it appears to be a hummingbird specialist. Three tactics were used by the hawks to hunt hummingbirds: typical Accipiter still-hunting (probably not specifically for hummingbirds), waiting in ambush […]
Long-term changes in nest defense intensity of the spanish Imperial Eagle Aquila adalberti.
Spanish Imperial Eagle (Aquila adalberti) Science Article 1 abstract This paper deals with the variations recorded in the nest defence of the Imperial Eagle Aquila adalberti after the declaration of Donana as a national park (Parque Nacional Donana, SW Spain) and the cessation of strong human pressure. Increases have been detected in the defence and […]
Causes and consequences of breeding dispersal in the Sparrowhawk Accipiter nisus
Sparrowhawk (Accipiter nisus) Science Article 1 abstract Sparrowhawks Accipiter nisus were present on particular territories for only one breeding season, but others were present on the same territory for up to eight seasons. Short periods of occupancy were due partly to mortality and partly to about one third of surviving birds of both sexes changing […]
A test of the condition-bias hypothesis yields different results for two species of sparrowhawks (Accipiter)A Test Of The Condition-Bias Hypothesis Yields Different Results For Two Species Of Sparrowhawks (Accipizter)
Sparrowhawk (Accipiter nisus) Science Article 2 abstract Determination of body condition of birds is important for many field studies. However, when using trapping methods based on food as a lure, the sample of trapped birds could be biased toward individuals in poor physical condition. We provide information on body mass, body condition, and sex and […]
WEIGHTS, BREEDING, AND SURVIVAL IN EUROPEAN SPARROWHAWKS
Sparrowhawk (Accipiter nisus) Science Article 5 abstract No significant diurnal variation in mean weight was detected in trapped European Sparrowhawks (Accipiter nisus). Weights of males fluctuated rather little through the year, but were highest in March and lowest in August. During the breeding cycle, males lost weight slightly in the prelay/early laying periods, when they […]
Age-related trends in the breeding success of individual female Sparrowhawks Accipiter nisus
Sparrowhawk (Accipiter nisus) Science Article 4 abstract Overall, female Sparrowhawks improved in the mean number of young they raised per year up to the 5th year of life, and then declined. An attempt is made to find to what extent this mean trend is caused by similar trends in the breeding of individual females, and […]
The abundance of essential vitamins in food chains and its impacton avian reproduction
Sparrowhawk (Accipiter nisus) Science Article 3 abstract Birds produce fewer or less viable eggs if the micro-nutrient requirements for reproduction cannot be met. Forexample, embryos from failed eggs of European sparrowhawks Accipiter nisus often show anomalies that indicate vitamin B2deficiency. B2 is only produced by plants and is propagated through the food chain. Here, egg […]
Notes on the Snail Kite in Surinam.
Snail Kite (Rostrhamus sociabilis) Science Article 1 abstract The coastal plain of Surinam the Snail Kite (Rostrhamus sociabilis) is the most numerous hawk wherever freshwater marshes occur. The cultivation of rice, which inundates large areas during part of the year, has undoubtedly expanded its feeding grounds. When the rice is growing the birds concentrate along […]