Editing Common buzzard (section)

===Nesting territories and density===
Home ranges of common buzzards are generally {{cvt|0.5|to|2|sqkm}}.<ref name= Brown/> The size of breeding territory seem to be generally correlated with food supply.<ref name= Brown/><ref name= Kruger>Krüger, O. (2004). ''The importance of competition, food, habitat, weather and phenotype for the reproduction of Buzzard Buteo buteo''. Bird Study, 51(2), 125–132.</ref> In a German study, the range was {{cvt|0.8|to|1.8|sqkm}} with an average of {{cvt|1.26|sqkm}}.<ref name= Schindler/> Some of the lowest pair densities of common buzzards seem to come from [[Russia]]. For instance, in [[Kerzhenets Nature Reserve]], the recorded density was 0.6 pairs per {{cvt|100|sqkm}} and the average distance of nearest neighbors was {{cvt|3.8|km}}.<ref>Novikova, L. (2009). ''Number and Distribution of the Common Buzzard in the Kerzhenskiy State Nature Reserve, Russia''. Raptors Conservation, (16).</ref> The [[Snowdonia]] region of northern [[Wales]] held a pair per {{cvt|9.7|sqkm}} with a mean nearest neighbor distance of {{cvt|1.95|km}}; in adjacent [[Migneint]], pair occurrence was {{cvt|7.2|sqkm}}, with a mean distance of {{cvt|1.53|km}}.<ref>Dare, P. J., & Barry, J. T. (1990). ''Population size, density and regularity in nest spacing of Buzzards Buteo buteo in two upland regions of North Wales''. Bird Study, 37(1), 23–29.</ref> In the [[Macizo de Teno|Teno massif]] of the [[Canary Islands]], the average density was estimated as 23 pairs per {{cvt|100|sqkm}}, similar to that of a middling continental population.<ref name= Rodriguez>Rodríguez, B., Siverio, F., Rodríguez, A., Siverio, M., Hernández, J. J., & Figuerola, J. (2010). ''Density, habitat selection and breeding biology of Common Buzzards Buteo buteo in an insular environment''. Bird Study, 57(1), 75–83.</ref> On another set of islands, on [[Crete]] the density of pairs was lower at 5.7 pairs per {{cvt|100|sqkm}}; here buzzards tend to have an irregular distribution, some in lower intensity harvest olive groves but their occurrence actually more common in agricultural than natural areas.<ref>Tzortzakaki, O., Simaiakis, S., & Xirouchakis, S. (2012). ''Abundance of common buzzards (Buteo buteo) in olive monocultures in the island of Crete''. Journal of Biological Research, 17, 44.</ref> In the Italian [[Alps]], it was recorded in 1993–96 that there were from 28 to 30 pairs per {{cvt|100|sqkm}}.<ref name= Sergio/> In central Italy, density average was lower at 19.74 pairs per {{cvt|100|sqkm}}.<ref>Cerasoli, M., & Penteriani, V. (1996). ''Common Buzzards (Buteo buteo) in Central Italy''. J. Raptor Res., 30(3), 130–135.</ref> Higher density areas are known than those above. Two areas of [[the Midlands]] of [[England]] showed occupancies of 81 and 22 territorial pairs per {{cvt|100|sqkm}}. High buzzard densities there were associated with high proportions of unimproved pasture and mature woodland within the estimated territories.<ref name=Sim/> Similarly high densities of common buzzards were estimated in central [[Slovakia]] using two different methods, here indicating densities of 96 to 129 pairs per {{cvt|100|sqkm}}.<ref name= Sotnar2>Šotnár, K., & Topercer, J. (2009). ''Estimating density, population size and dynamics of Common Buzzard (Buteo buteo) in the West Carpathian region by a new method''. Slovak Raptor Journal, 3, 1–12.</ref> Despite claims from the study of the English midlands were the highest known territory density for the species, a number ranging from 32 to 51 pairs in wooded area of merely {{cvt|22|sqkm}} in [[Czech Republic]] seems to surely exceed even those densities. The Czech study hypothesized that fragmentation of forest in human management of lands for [[Mouflon|wild sheep]] and [[deer]], creating exceptional concentrations of prey such as voles, and lack of appropriate habitat in surrounding regions for the exceptionally high density.<ref name= Sim/><ref>Voříšek, P. (2000). ''An extremely high population density of common buzzard (Buteo buteo) in Biosphere Reserve Pálava (Czech Republic) and its possible causes''. Buteo, 11, 51–56.</ref>

In the North-Estonian [[Neeruti Landscape Conservation Area|Neeruti landscape reserve]] (area 1250 ha), Marek Vahula found 9 populated nests in 1989 and 1990. One nest was found in 1982 and is apparently the oldest known nest that is still populated today.{{Citation needed|date=February 2023}}

[[File:Buteo buteo (553474414).jpg|thumb|left|A territorial dogfight between three buzzards in the [[Azores]].]]
Common buzzards maintain their territories through flight displays. In Europe, territorial behaviour generally starts in February. However, displays are not uncommon throughout year in resident pairs, especially by males, and can elicit similar displays by neighbors.<ref name= Ferguson-Lees/><ref name= Brown/> In them, common buzzards generally engage in high circling, spiraling upward on slightly raised wings. Mutual high circling by pairs sometimes go on at length, especially during the period prior to or during breeding season. In mutual displays, a pair may follow each other at {{cvt|10|-|50|m}} in level flight. During the mutual displays, the male may engage in exaggerated deep flapping or zig-zag tumbling, apparently in response to the female being too distant. Two or three pairs may circle together at times and as many as 14 individual adults have been recorded over established display sites.<ref name= Ferguson-Lees/><ref>Forsman, D., & Solonen, T. (1984, January). ''Censusing breeding raptors in southern Finland: methods and results''. In Annales Zoologici Fennici (pp. 317–320). Finnish Academy of Sciences, Societas Scientiarum Fennica, Societas pro Fauna et Flora Fennica and Societas Biologica Fennica Vanamo.</ref> Sky-dancing by common buzzards have been recorded in spring and autumn, typically by male but sometimes by female, nearly always with much calling. Their sky-dances are of the rollercoaster type, with upward sweep until they start to stall, but sometimes embellished with loops or rolls at the top. Next in the sky-dance, they dive on more or less closed wings before spreading them and shooting up again, upward sweeps of up to {{cvt|30|m}}, with dive drops of up to at least {{cvt|60|m}}. These dances may be repeated in series of 10 to 20. In the climax of the sky dance, the undulations become progressive shallower, often slowing and terminating directly onto a perch. Various other aerial displays include low contour flight or weaving among trees, frequently with deep beats and exaggerated upstrokes which show underwing pattern to rivals perched below.<ref name= Ferguson-Lees/><ref>Negro, J. J., & Galván, I. (2018). ''Behavioural Ecology of Raptors''. In Birds of Prey (pp. 33–62). Springer, Cham.</ref> Talon grappling and occasionally cartwheeling downward with feet interlocked has been recorded in buzzards and, as in many raptors, is likely the physical culmination of the aggressive territorial display, especially between males.<ref name= Brown/><ref>Simmons, R. E., & Mendelsohn, J. M. (1993). ''A critical review of cartwheeling flights of raptors''. Ostrich, 64(1), 13–24.</ref> Despite the highly territorial nature of buzzards and their devotion to a single mate and breeding ground each summer, there is one case of a [[Polyandry in animals|polyandrous]] trio of buzzards nesting in the [[Canary Islands]].<ref>Barrientos, R., & López-Darias, M. (2006). ''A case of a polyandrous trio of Eurasian buzzards (Buteo buteo) on Fuerteventura Island, Canary Islands''. Journal of Raptor Research, 40(4), 305–306.</ref>