The role of mosaic grasslands in agricultural systems for preserving feeding sites of Rollers (Coracias garrulus)
Abstract
Decline in populations of farmland and grassland birds has been attributed to the recent changes of agricultural practice in Europe. These changes may affect the availability and quality of food resources. The usage of traditional grassland farming methods and conservation of the remains of natural grasslands may contribute to the preservation of feeding sites of insectivorous bird species. In this study we compared abundance and seasonal trends of food supply and breeding parameters of Roller (Coracias garrulus) in mosaic grasslands and an extensive, natural grassland. During the nestling period, the combination of pitfall traps and sweep-net sampling was used to estimate arthropod abundance in the study plots. We checked nest-boxes of rollers weekly to determine breeding parameters. Frequency of Orthopteras collected by sweep-netting had significant effect on hatching, fledging and reproductive success. The total amount of Orthoptera’s dry biomass collected by sweep-netting was higher in the extensive natural grassland, but sampling dates had no effect. The seasonal changes in food supply were similar in both of the habitats and declined during the nestling period. However, arthropods’ dry biomass, collected by pitfall traps, did not differ in the two sites. Clutch size, number of hatchlings and fledglings, and reproductive success did not differ significantly between the two habitats. Our results supported the idea that mosaic grasslands in agricultural systems can serve as food reservoirs for insectivorous birds.
References
Avilés, J. M., Sanchez, J. M., Sanchez, A. & Parejo, D. (1999): Breeding biology of the Roller Coracias garrulus in farming areas of the southwest Iberian Peninsula. – Bird Study 46: 217–223.
Avilés, J. M. & Pajero, D. (2004): Farming practices and Roller Coracias garrulus conservation in south-west Spain. – Bird Conservation International 14: 173–181.
Benton, T. G. , Bryant, D. M. , Cole L. & Crick H. Q. P. (2004): Linking agricultural practice to insect and bird populations: a historical study over three decades. – Journal of Applied Ecology 39: 673–687.
BirdLife International (2004): Birds in Europe: population estimates, trends and conservation status. BirdLife International, Cambridge, UK (BirdLife Conservation Series no. 12)
Britschgi, A., Spaar, R. & Arlettez, R. (2006): Impact of grassland farming intensification on the breeding ecology of an indicator insectivorous passerine, the Whinchat Saxicola rubetra: Lessons for overall Alpine meadowland management. – Biological Conservation 130: 193–205.
Cramp,S., Perrins ,C. M. & Brooks, D. J. (szerk.) (1993): Handbook of the birds of Europe, the Middle East and North Africa-birds of the Western Palearctic Volume 7. Oxford University Press
Di Giulio, M., Edwards, P. J. & Meister, E. (2001): Enhancing insect diversity in agricultural grasslands: the roles of management and landscape structure. – Journal of Applied Ecology 38: 310–319.
Donald, P. F., Sanderson F. J., Burfiel, I. J. & Bommel, F. P. J. (2006): Futher evidencie of continent-wide impacts of agricultural intensification on European farmland birds, 1990-2000. – Agriculture, Ecosystems & Environment – 116: 189–196
Fry, C. H. & Fry, K. (1999): Kingfishers, Bee-Eaters & Rollers. Christopher Helm, A & C Black. London.
Fuller, R. J., Hill, D. & Tucker, G. (1991): Feeding the birds down on the farm: perspectives from Britain. – Ambio 20: 232–237.
Golawski, A. & Golawski, S. (2008): Habitat preference in territories of the Red-backed Shrike Lanius Collurio and their food richness in an extensive agriculture landscape. – Acta Zoologica Academiae Scientiarum Hungaricae 54(1): 89–97.
Hagemeijer, W. J. M. & Blair, M. J. (szerk.) (1997): The EBCC Atlas of European Breeding Birds. Their distribution and abundance. London: T. and A. D. Poyser.
Mand, R., Tilgar, V., Lohmus A. & Leivits, A. (2005): Providing nest boxes for hole-nesting birds- Does habitat metter? – Biodiversity and Conservation 14: 1823–1840.
Molnár, Gy. (1998): A szalakóta (Coracias garrulus) költésbiológiájának és táplálkozásának vizsgálata a Dél-Alföldön mesterséges telepítése kapcsán. – Ornis Hungarica 8(Suppl. 1): 119–124.
Newton, I. (2004): The recent declines of farmland bird populations in Britain: an appraisal of causal factors and conservation actions. – Ibis 146: 579–600.
Rodrigez, J., Avilés, J. M. & Pajero, D. (2011): The value of nestboxes in the conservation of Eurasian Rollers Coracias garrulus in southern Spain. – Ibis 153: 735–745.
Snow, D. W. & Perrins C. M. (1998): The birds of the Western Palearctic. Concise edition. Oxford University Press.
Tucker, G. M. & Evans, M. I. (1997): Habitats for birds in Europe: a conservation strategy for the wider environment. Cambridge, U.K.: BirdLife International (BirdLife Conservation Series no. 6)
Vickery, J. A., Tallowin, J. R., Feber, R. E., Asteraki, E. J., Atkinson, P. W., Fuller, R. J. & Brown, V. K. (2001): The management of lowland neutral grasslands in Britain: effects of agricultural practices on birds and their food rescources. – Journal of Applied Ecology 38: 647–664
