[
Aparicio, J. M. & Bonal, R. 2002. Why do some traits show higher fluctuating asymmetry than others? A test of hypotheses with tail feathers of birds. – Heredity 89(2): 139–144.
]Search in Google Scholar
[
Arroyo, B. E. 2008. Diet of Montagu’s Harrier Circus pygargus in central Spain: analysis of temporal and geographic variation. – Ibis 139(4): 664–672. DOI: 10.1111/j.1474-919x.1997.tb04689.x
]Search in Google Scholar
[
Arroyo, B. E. & Garcia, J. T. 2006. Diet composition influences annual breeding success of Montagu’s Harriers Circus pygargus feeding on diverse prey. – Bird Study 53(1): 73–78. DOI: 10.1080/00063650609461418
]Search in Google Scholar
[
Baumel, J. J. 1993. Handbook of avian anatomy: Nomina Anatomica Avium. – Publications of the Nuttall Ornithological Club (USA), no. 23
]Search in Google Scholar
[
Bernays, E. A., Singer, M. S. & Rodrigues, D. 2004. Foraging in nature: foraging efficiency and attentiveness in caterpillars with different diet breadths. – Ecological Entomology 29(4): 389–397. DOI: 10.1111/j.0307-6946.2004.00615.x
]Search in Google Scholar
[
Buij, R. 2012. Pallid Harrier Circus macrourus bird hunting behaviour and capture success in northern Cameroon. – Ostrich 83(1): 27–32. DOI: 10.2989/00306525.2012.680263
]Search in Google Scholar
[
Buij, R., Van der Goes, D., De Iongh, H. H., Gagare, S., Haccou, P., Komdeur, J. & De Snoo, G. 2011. Interspecific and intraspecific differences in habitat use and their conservation implications for Palaearctic harriers on Sahelian wintering grounds. – Ibis 154(1): 96–110. DOI: 10.1111/j.1474-919x.2011.01200.x
]Search in Google Scholar
[
Butet, A. & Leroux, A. A. 1993. Effect of prey on a predator’s breeding success. A 7 year study on common vole (Microtus arvalis) and Montagu’s Harrier (Circus pygargus) in a west France marsh. – Acta Oecologica (Montrouge) 14(6): 857–865.
]Search in Google Scholar
[
Cardador, L., Planas, E., Varea, A. & Mañosa, S. 2012. Feeding behaviour and diet composition of Marsh Harriers Circus aeruginosus in agricultural landscapes. – Bird Study 59(2): 228–235. DOI: 10.1080/00063657.2011.648165
]Search in Google Scholar
[
Clark, C. J., LePiane, K. & Liu, L. 2020. Evolutionary and ecological correlates of quiet flight in nightbirds, hawks, falcons, and owls. – Integrative and Comparative Biology 60(5): 1123–1134. DOI: 10.1093/icb/icaa039
]Search in Google Scholar
[
Clarke, R., Bourgonje, A. & Castelijns, H. 1993. Food niches of sympatric Marsh Harriers Circus aeruginosus and Hen Harriers C. cyaneus on the Dutch coast in winter. – Ibis 135(4): 424–431. DOI: 10.1111/j.1474-919x.1993.tb02115.x
]Search in Google Scholar
[
Clarke, R., Combridge, M. & Combridge, P. 2008. A comparison of the feeding ecology of wintering Hen Harriers Circus cyaneus centred on two heathland areas in England. – Ibis 139(1): 4–18. DOI: 10.1111/j.1474-919x.1997.tb04498.x
]Search in Google Scholar
[
Coles, R. B. & Guppy, A. 1988. Directional hearing in the Barn Owl (Tyto alba). – Journal of Comparative Physiology A, 163(1): 117–133. DOI: 10.1007/bf00612002
]Search in Google Scholar
[
Cramp, S. 1980. Handbook of the birds of Europe, the Middle East, and North Africa: the birds of the western Palearctic, Vol. 2. Hawks to bustards. – Oxford University Press
]Search in Google Scholar
[
Fedriani, J. M., Fuller, T. K., Sauvajot, R. M. & York, E. C. 2000. Competition and intraguild predation among three sympatric carnivores. – Oecologia 125: 258–270. DOI: 10.1007/s004420000448
]Search in Google Scholar
[
Franklin, A. B., Anderson, D. R., Gutiérrez, R. J. & Burnham, K. P. 2000. Climate, habitat quality, and fitness in Northern Spotted Owl populations in northwestern California. – Ecological Monographs 70(4): 539–590. DOI: 10.1890/0012-9615(2000)070[0539:chqafi]2.0.co;2
]Search in Google Scholar
[
Garcia, J. T. & Arroyo, B. E. 2002. Intra- and interspecific agonistic behaviour in sympatric harriers during the breeding season. – Animal Behaviour 64(1): 77–84. DOI: 10.1006/anbe.2002.3035
]Search in Google Scholar
[
Garcia, J. T. & Arroyo, B. E. 2004. Food-niche differentiation in sympatric Hen Circus cyaneus and Montagu’s Harriers Circus pygargus. – Ibis 147(1): 144–154. DOI: 10.1111/j.1474-919x.2004.00377.x
]Search in Google Scholar
[
Gerstell, A. T. & Bednarz, J. C. 1999. Competition and patterns of resource use by two sympatric raptors. – Condor 101: 557–565.
]Search in Google Scholar
[
Güntürkün, O., Diekamp, B., Manns, M., Nottelmann, F., Prior, H., Swartz, A. & Skiba, M. 2000. Asymmetry pays: Visual lateralization improves discrimination success in Pigeons. – Current Biology 10(17): 1079–81. DOI: 10.1016/s0960-9822(00)00671-0
]Search in Google Scholar
[
Hamerstrom, F. 1969. A harrier population study. – In: Hickey, J. J. (ed.) Peregrine Falcon Populations: Their Biology and Decline. – Wisconsin University Press, Wisconsin, pp. 367–383.
]Search in Google Scholar
[
Klingenberg, C. P., Barluenga, M. & Meyer, A. 2002. Shape analysis of symmetric structures: quantifying variation among individuals and asymmetry. – Evolution 56(10): 1909–1920. DOI: 10.1111/j.0014-3820.2002.tb00117.x
]Search in Google Scholar
[
Korpimäki, E. & Norrdahl, K. 1991. Do breeding nomadic avian predators dampen population fluctuations of small mammals? – Oikos 62(2): 195–208. DOI: 10.2307/3545265
]Search in Google Scholar
[
Marquez, E. 2006. Sage: symmetry and asymmetry in geometric data. – Ver 1.0.http://www.personal.umich.edu/~emarquez/morph/
]Search in Google Scholar
[
Millon, A., Bourrioux, J. L., Riols, C. & Bretagnolle, V. 2002. Comparative breeding biology of Hen and Montagu’s Harriers: an eight-year study in north-eastern France. – Ibis 144: 94–105. DOI: 10.1046/j.0019-1019.2001.00009.x
]Search in Google Scholar
[
Nagy, J. & Tökölyi, J. 2014. Phylogeny, historical biogeography and the evolution of migration in accipitrid birds of prey (Aves: Accipitriformes). – Ornis Hungarica 22: 15–35. DOI: 10.2478/orhu-2014-0008
]Search in Google Scholar
[
Nishikawa, K. C. 2002. Evolutionary convergence in nervous systems: insights from comparative phylogenetic studies. – Brain, Behavior and Evolution 59(5–6): 240–249. DOI: 10.1159/000063561
]Search in Google Scholar
[
Newton, I. 1980. The role of food in limiting bird numbers. – Ardea 55(1–2): 11–30.
]Search in Google Scholar
[
Norberg, R. Å. 1978. Skull asymmetry, ear structure and function, and auditory localization in Tengmalm’s Owl, Aegolius funereus (Linné). – Philosophical Transactions of the Royal Society of London, Biological Sciences 282(991): 325–410. DOI: 10.1098/rstb.1978.0014
]Search in Google Scholar
[
Norberg, R. Å. 2002. Independent evolution of outer ear assymmetry among five owl lineages; morphology, function and selection. – In: Newton, I., Kavanagh, R., Olsen, J. & Taylor, I. (eds.) Ecology and Conservation of Owls. – Collingwood, Victoria, Australia: Csiro Publishing, pp. 329–42.
]Search in Google Scholar
[
Oatley, G., Simmons, R. E. & Fuchs, J. 2015. A molecular phylogeny of the harriers (Circus, Accipitridae) indicate the role of long distance dispersal and migration in diversification. – Molecular Phylogenetics and Evolution 85: 150–160. DOI: 10.1016/j.ympev.2015.01.013
]Search in Google Scholar
[
Parés-Casanova, P. M. & Salas-Bosch, J. 2020. Comparison of orbital asymmetries among some raptor species: “when size does not matter”. – Slovak Raptor Journal 14(1): 23–27. DOI: 10.2478/srj-2020-0005
]Search in Google Scholar
[
Pecsics, T., Laczi, M., Nagy, G., Kondor, T. & Csörgő, T. 2018. Analysis of skull morphometric characters in Owls (Strigiformes). – Ornis Hungarica 26(1): 41–53. DOI: 10.1515/orhu-2018-0003
]Search in Google Scholar
[
Peters, J. L. 1931. Check-list of Birds of the World. – Harvard University Press, Cambridge
]Search in Google Scholar
[
Redpath, S. M. 1992. Behavioural interactions between Hen Harriers and their moorland prey. – Ornis Scandinavica 23(1): 73–80. DOI:10.2307/3676429
]Search in Google Scholar
[
Rice, W. R. 1980. Acoustical localization of concealed prey by the diurnal harrier (Circus cyaneus). – PhD Dissertation, Corvallis, Oregon, Oregon State University
]Search in Google Scholar
[
Rice, W. R. 1982. Acoustical location of marsh hawk: adaptations to concealed prey. – Auk 99: 403–413.
]Search in Google Scholar
[
Rohlf, F. J. 2010. TpsDig, version 2.16. – Department of Ecology and Evolution, State University of New York, Stony Brook, USA
]Search in Google Scholar
[
Russell, R. W. 1991. Nocturnal flight by migrant “diurnal” raptors. – Journal of Field Ornithology 62(4): 505–508.
]Search in Google Scholar
[
Simmons, R. E. 2000. Harriers of the World: Their Behaviour and Ecology, Oxford Ornithology Series, 11. – Oxford University Press on Demand
]Search in Google Scholar
[
Sun, Y., Si, G., Wang, X., Wang, K. & Zhang, Z. 2018. Geometric morphometric analysis of skull shape in the Accipitridae. – Zoomorphology 137: 445–456. DOI: 10.1007/s00435-018-0406-y
]Search in Google Scholar
[
Terraube, J., Arroyo, B., Madders, M. & Mougeot, F. 2011. Diet specialisation and foraging efficiency under fluctuating vole abundance: a comparison between generalist and specialist avian predators. – Oikos 120(2): 234–244. DOI: 10.1111/j.1600-0706.2010.18554.x
]Search in Google Scholar
[
Thiollay, J. M. 1994. Accipitridae (Hawks and eagles). – In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D. A. & de Juana, E. (eds.) 1992–2011. Handbook of the Birds of the World, Vol. 2. New World Vultures to Guineafowl. – Lynx Edicions, Barcelona, pp. 52–206.
]Search in Google Scholar
[
Torcida, S., Gonzalez, P. & Lotto, F. 2016. A resistant method for landmark-based analysis of individual asymmetry in two dimensions. – Quantitative Biology 4(4): 270–282. DOI: 10.1007/s40484-016-0086-x
]Search in Google Scholar
[
Tornberg, R. & Haapala, S. 2013. The diet of the Marsh Harrier Circus aeruginosus breeding on the isle of Hailuoto compared to other raptors in northern Finland. – Ornis Fennica 90(2): 103–116.
]Search in Google Scholar
[
Van Grouw, K. 2012. I. Accipitres. – In: The Unfeathered Bird. – Princeton University Press, pp. 30–51. DOI: 10.1515/9781400844890.30
]Search in Google Scholar
[
Zelditch, M., Swiderski, D., Sheets, D. H. & Fink, W. 2004. Geometric Morphometrics for Biologists: A primer. – Elsevier Academic Press, Waltham, MA.
]Search in Google Scholar
[
Zusi, R. L. 1993. Patterns of diversity in the avian skull. – In: Hanken, J. & Hall, B. K. (eds.) The Skull, Vol. 2. Patterns of Structural and Systematic Diversity. – University of Chicago Press, Chicago, pp. 391–437.
]Search in Google Scholar
[
Zweers, G. A., Berkhoudt, H. & Berge, J. V. 1994. Behavioral mechanisms of avian feeding. – In: Bels, V. L., Chardon, M. & Vandewalle, P. (eds.) Biomechanics of Feeding in Vertebrates. – Springer, Berlin, Heidelberg, pp. 241–279.
]Search in Google Scholar
