Spanish Sparrow (Passer hispaniolensis) Science Article 1 abstract […]. The study was carried out in May and June 2000 in Castro Verde, Southern Portugal (37 deg 41?N, 08 deg 03?W). The Castro Verde region is a cereal crop steppe, alternating with fallow grounds, which are usually grazed by sheep and cattle. The sparrows nest in […]
Category: Eurasia
Spanish Sparrow Passer hispaniolensis breeding success in 2002 in southern Portugal
Spanish Sparrow (Passer hispaniolensis) Science Article 2 abstract […]. During the breeding season of 2002 (from May to June), the breeding biology of the Spanish Sparrow was studied in the region of Castro Verde (37 deg 41?N, 08 deg 03?W, Alentejo, Southern Portugal). The Castro Verde region is a cereal steppe with cereal crops alternating […]
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 […]
Biometrics of the Southern Grey Shrike Lanius meridionalis in relation to age and sex.
Southern Grey Shrike (Lanius meridionalis) Science Article 1 abstract The biometrics of Southern Grey Shrike Lanius meridionalis and differences from the closely related Great Grey Shrike L. excubitor are poorly characterised. The aim of this study was to describe sex and age variation in external biometric measurements for the nominate Southern Grey Shrike L. m. […]
Diet composition and prey choice of the Southern grey shrike Lanius meridionalis L. in South-eastern Spain: the importance of vertebrates in the diet
Southern Grey Shrike (Lanius meridionalis) Science Article 2 abstract The Southern grey shrike consumes several beetle types, grasshoppers, and, during the breeding period, lizards. Birds and small mammals are captured incidentally. It consistently rejects prey smaller than 10 mm long, and prey are larger during the breeding period and summer. Compared with other populations of […]
Blue eggs do not reduce nest predation in the song thrush,Turdus philomelos
Song Thrush (Turdus philomelos) Science Article 2 abstract Many passerine birds with open cup-shaped nests lay blue or blue-green eggs. In thrushes, blue eggs may be cryptic and provide camouflage by imitating spots of light on green leaves. Alternatively, egg coloration may be selectively neutral because nest predators detect nests and not eggs, or it […]