AVIS-IBIS

Birds of Indian Subcontinent

Breeding biology of Montagu's Harrier Circus pygargus L. in agricultural environments of southwest Spain; comparison with other populations in the western Palearctic

Publication Type:Journal Article
Year of Publication:1997
Authors:Corbacho, C, Sánchez, JM, Sánchez, A
Journal:Bird Study
Volume:44
Date Published:1997
ISBN Number:0006-3657
Keywords:Accipitridae, Circus, Circus pygargus, Spain
Abstract:We studied the breeding biology of Montagu's Harrier in an agricultural habitat at various breeding sites in Extremadura (southwest Spain). Clear latitudinal trends were observed on laying date and clutch size compared to other Western Palearctic populations: as laying starts earlier, clutch size declines in southern populations. Climate and feeding could be the main factors involved. In addition to natural factors, the species' use of cultivated areas as nesting habitat at Southern latitudes is the major determinant of breeding success. Artificial nest management at harvest time has been shown to be effective in reducing losses due to farming activities. Such conservation measures reduce the mortality rate of nestlings and consequently increase the reproductive success of breeding pairs. Nevertheless, endogenous factors related to individual breeding condition limit the effect of artificial nest management. Mediterranean populations of Montagu's Harrier seem to be highly dependent on conservation measures because of the high failure rates for breeding in the absence of such intervention.We studied the breeding biology of Montagu's Harrier in an agricultural habitat at various breeding sites in Extremadura (southwest Spain). Clear latitudinal trends were observed on laying date and clutch size compared to other Western Palearctic populations: as laying starts earlier, clutch size declines in southern populations. Climate and feeding could be the main factors involved. In addition to natural factors, the species' use of cultivated areas as nesting habitat at Southern latitudes is the major determinant of breeding success. Artificial nest management at harvest time has been shown to be effective in reducing losses due to farming activities. Such conservation measures reduce the mortality rate of nestlings and consequently increase the reproductive success of breeding pairs. Nevertheless, endogenous factors related to individual breeding condition limit the effect of artificial nest management. Mediterranean populations of Montagu's Harrier seem to be highly dependent on conservation measures because of the high failure rates for breeding in the absence of such intervention.
URL:http://www.tandfonline.com/doi/abs/10.1080/00063659709461052
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith