References
- Bautista, L. M., García, J. T., Calmaestra, R. G., Palacin, C., Martín, C. A., Morales, M. B., Bonal, R. & Viñuela, J. 2004. Effect of weekend road traffic on the use of space by raptors. – Conservation Biology 18(3): 1–7. DOI: 10.1111/j.1523-1739.2004.00499.x
- Bibby, C., Jones, M. & Marsden, S. 1999. Expedition Field Techniques. – Bird Surveys. Royal Geographical Society, London
- Bijleveld, M. 1974. Birds of Prey in Europe. – The MacMillan Press Ltd., London
- BirdLife International 2021. Species factsheet: Aquila heliaca. – http://www.birdlife.org on 06/03/2021.
- Bisson, I. A., Ferrer, M. & Bird, D. M. 2002. Factors influencing nest-site selection by Spanish Imperial Eagles. – Journal of Field Ornithology 73(3): 298–302. DOI: 10.1648/0273-8570-73.3.298
- Bondev, Z. 1991. Flora in Bulgaria. – Publishing House “Kliment Ohridsky”, Sofia (in Bulgarian)
- Castano, J. P. & Guzman, J. A. 1995. Reproductive aspects of Aquila adalberti and Aquila chrysaetos in eastern Sierra Morena. – Ardeola 42(1): 83–89.
- Demerdzhiev, D., Horváth, M., Kovács, A., Stoychev, S. & Karyakin, I. 2011a Status and population trend of the Eastern Imperial Eagle (Aquila heliaca) in Europe in the period 2000–2010. – Acta Zoologica Bulgarica Suppl. 3: 5–14.
- Demerdzhiev, D., Dobrev, D., Popgeorgiev, G., Stoychev, S. in press. Landscape alteration affecting the demography of an endangered avian predator by reducing the habitat quality. – Journal of Avian Research
- Demerdzhiev, D. A., Gradev, G. Zh., Stoychev, S. A., Ivanov, I., Petrov, Tz. & Marin, S. A. 2011b Increase of the population of the Eastern Imperial Eagle (Aquila heliaca) in Bulgaria. – Acta Zoologica Bulgarica Suppl. 3: 41–54.
- Demerdzhiev, D., Stoychev, S., Dobrev, D., Spasov, S. & Terziev, N. 2014. Conservation measures undertaken to improve the population status of Eastern Imperial Eagle (Aquila heliaca) in Bulgaria. – Slovak Raptor Journal 8(1): 27–39. DOI: 10.2478/srj-2014-0007
- Dobrev, D. 2009. Some aspects of nest etology of the Eastern Imperial Eagle (Aquila heliaca) (Aves: Accipitridae) in Sakar mountain. – Ecologia Balkanica 1: 60–66.
- Fernandez, C. & Azkona, P. 1993. Human disturbance affects parental care of Marsh Harriers and nutritional status of nestlings. – Journal of Wildlife Management 57(3): 602–608. DOI: 10.2307/3809289
- Fernandez-Juricic, E. 2002. Can human disturbance promote nestedness? A case study with breeding birds in urban habitat fragments. – Oecologia 131(2): 269–278. DOI: 10.1007/s00442-002-0883-y
- Ferrer, M. & Harte, M. 1997. Habitat selection by immature Spanish Imperial Eagles during the dispersal period. – Journal of Applied Ecology 34(6): 1359–1364. DOI: 10.2307/2405253
- Ferrer, M., Negro, J., Casado, E., Muriel, R. & Madero, A. 2007. Human disturbance and the conservation of the Spanish Imperial Eagle: A response to Gonzalez et al. 2006. – Animal Conservation 10(3): 293–294. DOI: 10.1111/j.1469-1795.2006.00090.x
- Forsman, D. 2005. Eastern Imperial Eagle plumages. – Alula 4: 147–152.
- Fraser, J. D., Frenzel, L. & Mathisen, J. E. 1985. The impact of human activities on breeding Bald Eagles in north-central Minnesota. – Journal of Wildlife Management 49: 585–592. DOI: 10.2307/3801676
- Gonzalez, L. M., Arroyo, B., Margalida, A., Sanchez, R. & Oria, J. 2006. Effect of human activities on the behaviour of breeding Spanish Imperial Eagle (Аquila adalberti): management implications for the conservation of a threatened species. – Animal Conservation 9(1): 85–93. DOI: 10.1111/j.1469-1795.2005.00016.x
- Gonzalez, L. M., Bustamante, J. & Hiraldo, F. 1990. Factors influencing the present distribution of the Spanish Imperial Eagle (Aquila adalberti). – Biological Conservation 51(4): 311–319. DOI: 10.1016/0006-3207(90)90116-7
- Gonzalez, L. M., Bustamante, J. & Hiraldo, F. 1992. Nesting habitat selection by the Spanish Imperial Eagles Aquila adalberti. – Biological Conservation 59(1): 45–50. DOI: 10.1016/0006-3207(92)90712-V
- Grier, J. W. & Fyfe, R. W. 1987. Preventing research and management disturbance. – In: Pendleton, B. A. G., Millsap, B. A., Cline, K. W. & Bird, O. M. (eds.) Raptor Management Techniques Manual. – Scientific Technical Ser. No. 10, National Wildlife Federation, pp. 173–182.
- Grubb, T. G. Bowerman, W. W., Giesy, J. P. & Dawson, G. A. 1992. Responses of breeding Bald Eagles Haliaetus leucocephalus to human activities in northcentral Michigan. – Canadian Field-Naturalists 106(4): 443–453.
- Grubb, T. G. & King, R. M. 1991. Assessing human disturbance of breeding Bald Eagles with classification tree models. – Journal of Wildlife Management 55(3): 500–511. DOI: 10.2307/3808982
- Heath, M. F. & Evans, M. I. (eds.) 2000. Important Bird Areas in Europe: Priority Sites for Conservation. – BirdLife Conservation Series No. 8., BirdLife International, Cambridge, UK
- Holmes, T. L., Knight, R. L., Stegall, L. & Craig, G. R. 1993. Responses of wintering grassland raptors to human disturbance. – Wildlife Society Bulletin 21: 461–468.
- Horváth, M., Fehérvári, P., Szitta, T., Harnos, A., Kabai, P. & Moskát, Cs. 2009. Effects of infrastructural network on the distribution of Imperial Eagles in the Hungarian Plain. – In: Horváth, M. Habitat and prey selection in Imperial Eagles (Aquila heliaca). – PhD thesis chapter, Faculty of Science, Biological Institute, Eötvös Loránd University
- Jenny, D. 1992. Bruterfolg und Bestandsregulatione iner alpinen Population des Steinadlers Aquila chrysaetos [Breeding success and population regulation in the alpine population of the Golden Eagle Aquila chrysaetos]. – Der Ornithologische Beobachter 89: 1–43. (in German)
- Martínez-Abraín, A., Oro, D., Jiménez, D., Stewart, J. & Pullin, A. 2010. A systematic review of the effect of recreational activities on nesting birds of prey. – Basic and Applied Ecology 11(4): 312–319. DOI: 10.1016/j. baae.2009.12.011.
- McClure, Ch. J. W., Westrip, J. R. S., Johnson, J. A., Schulwitz, S. E., Virani, M. Z., Davies, R., Symes, A., Wheatley, H., Thorstrom, R., Amar, A., Buij, R., Jones, V. R., Williams, N. P., Buechley, E. R. & Butchart, S. H. M. 2018. State of the world’s raptors: Distributions, threats, and conservation recommendations. – Biological Conservation 227: 390–402. DOI: 10.1016/j.biocon.2018.08.012
- McGarigal, K., Anthony, R. G. & Isaacs, F. B. 1991. Interactions of human and Bald Eagles on the Columbia Riverestuary. – Wildlife Monographs 115: 3–47.
- McGrady, M. 1997. Aquila chrysaetos Golden Eagle. – BWPUpdate 1: 99–114.
- Patev, P. 1950. Birds in Bulgaria. – BAS, Sofia (in Bulgarian)
- Pauli, B., Spaul, R. & Heath, J. 2016. Forecasting disturbance effects on wildlife: Tolerance does not mitigate effects of increased recreation on wildlands. – Animal Conservation 20(3): 251–260. DOI: 10.1111/acv.12308
- Perona, A., Urios, V. & López-López, P. 2019. Holidays? Not for all. Eagles have larger home ranges on holidays as a consequence of human disturbance. – Biological Conservation 231: 59–66. DOI: 10.1016/j. biocon.2019.01.010
- Richardson, C. T. & Miller, C. K. 1997. Recommendations for protecting raptors from human disturbance: a review. – Wildlife Society Bulletin 25: 634–638.
- Ruddock, M. & Whitfield, D. 2007. A review of disturbance distances in selected bird species. – A report from Natural Research (Projects) Ltd. to Scottish Natural Heritage
- Ruhlen, T. D., Abbott, S., Stenzel, L. E. & Page, G. W. 2003. Evidence that human disturbance reduces Snowy Plover chick survival. – Journal of Field Ornithology 74(3): 300–304. DOI: 10.1648/0273-8570-74.3.300
- Stalmaster, M. V. & Newman, J. R. 1978. Behavioral responses of wintering Bald Eagles to human intrusion. – Journal of Wildlife Management 42(3): 506–513. DOI: 10.2307/3800811
- Statsoft 2011. STATISTICA (data analysis software system), version 10. – www.statsoft.com.
- Steidl, R. J. & Anthony, R. G. 1996. Responses of Bald Eagles to human activity during the summer in interior Alaska. – Ecological Applications 6(2): 482–491. DOI: 10.2307/2269385
- Swarthout, E. C. H. & Steidl, R. J. 2001. Flush responses of Mexican Spotted Owls to recreationists. – Journal of Wildlife Management 65(2): 312–317. DOI: 10.2307/3802910
- Verhulst, S., Oosterbeek, K. & Ens, B. J. 2001. Experimental evidence of effects of human disturbance on foraging and parental care in Oystercatchers. – Biological Conservation 101(3): 375–380. DOI: 10.1016/S0006-3207(01)00084-2
- Watson, J. 1994. Golden Eagle Aquila chrysaetos. – In: Tucker, G. M. & Heath, M. F. (eds.) Birds in Europe: Their Conservation Status. – BirdLife Conservation Series No 3., Cambridge, U.K., pp. 180–181.
- White, C. & Thurow, T. L. 1985. Reproduction of Ferruginous Hawks exposed to controlled disturbance. – Condor 87: 14–22.
- Zuberogoitia, I., Zabala, J., Martínez, J. A., Martínez, J. E. & Azkona, A. 2008. Effect of human activities on Egyptian Vulture breeding success. – Animal Conservation 11(4): 313–320. DOI: 10.1111/j.1469-1795.2008.00184.x.
- Zuberogoitia, I., Zabala-Albizua, J., Martínez, J., González-Oreja, J. & López-López, P. 2014. Effective conservation measures to mitigate the impact of human disturbances on the endangered Egyptian Vulture. – Animal Conservation 17(5): 410–418. DOI: 10.1111/acv.12107.