2022
Switch van adulte Scholeksters Haematopus ostralegus van agrarisch naar stedelijk gebied en het effect ervan op het broedsucces
Publication
Publication
Adult Oystercatchers Haematopus ostraleugus switching from rural to urban habitat, and its impact on reproductive success
In northern Drenthe, 15 adult female Oystercatchers breeding in farmland were captured on the nest. Twelve of these birds remained site-faithful for on average slightly more than four years after ringing, after which they disappeared. Nesting success in farmland was poor, with 31% of the pairs hatching their eggs and raising on average 0.09 young/pair. Three females that switched from farmland to an urban breeding site (breeding dispersal 0.9, 2.6 and 3.6 km) improved their nesting success considerably, from 20% (1 out of 5 nests raising at least one fledgling) to 64% (18 out of 28). In terms of young raised per pair, the difference was even larger, namely respectively 0.2 and 0.75 young raised per egg-laying pair. Nesting on low roofs (<6.5 m) was more successful than nesting on higher roofs (12 m), probably because in the latter case chicks departed only after they were fully fledged, whereas chicks on lower roofs jumped long before they were able to fly. In the course of the study, the farmland population declined from 12-13 pairs in 2008-09 to less than 4 in 2022 (797 ha), whereas the urban population doubled from 35 to a peak of 70 in 2019 (704 ha). In recent years urban numbers remained stable at slightly less than 70 pairs, an indication that all suitable breeding places in Assen are now being occupied. Replacements of lost breeding birds in farmland are recruited from the urban supply, but nevertheless the decline in farmland is continuing and nearing its nadir.
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Drentse vogels | |
CC BY 3.0 NL ("Naamsvermelding") | |
Organisation | Werkgroep Avifauna Drenthe |
B. Dijkstra, & R. Dillerop. (2022). Switch van adulte Scholeksters Haematopus ostralegus van agrarisch naar stedelijk gebied en het effect ervan op het broedsucces. Drentse vogels. |