RELATIONSHIP BETWEEN GRAZING INTENSITY, VEGETATION STRUCTURE AND SURVIVAL OF NESTS IN SEMI-NATURAL GRASSLANDS

One of the causes of decline of farmland birds in Europe is the loss of broods. Here, we investigated if region, cattle grazing intensity, habitat edges and vegetation structure around artificial nests influence predation, the major cause of broods’ loss. We placed artificial open ground nests (N =...

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Bibliographic Details
Main Authors: Erdos, S., Baldi, A., Batary, P.
Format: Article in Journal/Newspaper
Language:English
Published: 2011
Subjects:
630
Online Access:http://resolver.sub.uni-goettingen.de/purl?gs-1/7787
Description
Summary:One of the causes of decline of farmland birds in Europe is the loss of broods. Here, we investigated if region, cattle grazing intensity, habitat edges and vegetation structure around artificial nests influence predation, the major cause of broods’ loss. We placed artificial open ground nests (N = 304) resembling the nests of Skylark (Alauda arvensis), baited by one plasticine and one Quail egg in inside and edge habitats of extensively and intensively grazed grasslands in three regions in Hungary in 2003. Interestingly, none of the three factors (region, grazing intensity, edge effect) had significant effects on brood loss according to the generalised linear mixed model, however, interactions between region and management and among region, management and edge effect were significant. This suggests that the effect of management is not the same in different regions, and edge effect depends on both region and management. We also found that nest predation rate is lower if nests are placed in tall grass and greater vegetation cover. This pattern indirectly supports the negative effects of intensive grazing, which can remove most of the vegetation. Therefore, we suggest that extensive grazing should be favoured to conserve ground nesting birds, however, it is essential to avoid duplicating management regimes from one region to another, due to regional differences in the pattern of survival probability. peerReviewed