Reptielen als voer voor jonge buizerds
RAVON , Volume 14 - Issue 4 p. 74- 79
Reptiles as food for Buzzard chicks In the Netherlands, reptiles are routinely taken as food by buzzards (Buteo buteo) during the breeding season, although their proportion in the summer diet differs strongly between years, between regions and between pairs. On the Veluwe, in central Netherlands, reptiles were much less commonly caught than in the northern province of Drenthe. In 2012, snakes and slow worms (Anguis fragilis) were particularly common (N=32) among their prey (N=114) in Drenthe. Of these, all 8 adders (Vipera berus), 6 of 8 slow worms and 13 of 16 grass snakes (Natrix natrix) were found in a single nest, in an area with woodland and heathland harbouring a rather high density of reptiles. Fixed transects in the heathland, partly with refuges, produced sightings of 3,684 reptiles during 2004-2010, mostly adders (37.7%) but also viviparous lizards (Zootoca vivipara)(26.9%), slow worms (20.3%, almost exclusively beneath the refuges) and grass snakes (15.1%). Neither abundance nor catchability of other prey species, notably small mammals and birds, is known for this region. Hence, the question of whether this buzzard pair has a specialised diet cannot be answered. It is more likely that the basking behaviour of reptiles was influenced by the specific conditions of spring 2012. Long periods of cool, wet and windy weather were interspersed with short sunny periods, when the reptiles emerged in high numbers to bask. In their summer diet, as found on Veluwe and in Drenthe, the top three prey are Rabbit (Oryctolagus cuniculus), nestling Carrion Crow (Corvus corone) and Mole (Talpa europaea), together almost half of the total biomass.
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