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Population (Replaces BWP)From migration counts and studies in different countries, numbers seem to be more fluctuating than stable. However, estimates of populations and trends are difficult because of secretive habits during the breeding cycle. Therefore, the keyquestion is still whether Honey Buzzard populations tend towards stability (Glutz et al. 1971) or fluctuate (Galushin 1974). The answer seems to be that both st

rategies are used. Honey Buzzards are long-lived raptors: oldest ringed bird 28years 10 months. They are strongly K-selected with low reproductive output and often markedly philopatric. Some nests and territories were used for more than 20years (Kostrzewa 1985). Extraordinarily, a 1-year-old bird was proved breeding,while data from lifetables indicate shorter lifespans. Mean life expectation fo

r first-year birds was calculated at 2.2 years and for older birds 3.6 years (Bijlsma et al. 1993; n = 27). Swedish birds show first-year survival of 48.8%, second-year 85.8%, and adult 86% which will give a much higher lifespan (Tjernbergand Ryttmann 1994). However, Lakhani and Newton (1983) showed that lifespans calculated solely from lifetables and ignoring field observations of individually marked birds can overestimate mortality. In Russia, Honey Buzzards seemed to be not philopatric at all. Galushin (1974) found birds during the breeding season c.

1000 km (SD 375 km) from their ringing sites. This suggests possible nomadism.The hypothesis, therefore, is that Honey Buzzards show philopatry in optimal habitat (i.e. on dry soils with a good wasp population) but are more nomadic in suboptimal habitat with changing food resources (Kostrzewa 1987). In the German study area, weather during spring and early summer proved to be a limiting factor for territory numbers (Kostrzewa 1989).Population StudiesFour areas in The Netherlands showed slightly different trends (Bijlsma et al. 1993): in ZW-Drenthe, numbers slowly increased from 1970 onwards (2-12 pairs in 1991), two Veluwe areas were fairly stable (11-23 pairs in 1979-91, and 10-18 in1973-90, with maximum of 20 in several years, respectively), and the Nijmegen and Reichswald area was stable with a small decline from mid-1970s to mid-1980s (6-9 pairs 1969-92, with maximum of 10 in 1970). In Germany, two areas showed stro

ngly decreasing numbers: in the Rhineland, pairs declined from a maximum of 19 to a minimum of 4 pairs (1988) during 1979-89 (Kostrzewa 1991a), in the Mnsterlandpairs declined from 44 (1977) to 15 (1985) with a minimum of 10 pairs in 1984 (

F Csters in litt.). This decline continued during the 1990s (AG-Greifvgel, 1999).One area in Jutland (Denmark) also showed a decline, from 12 pairs in 1974 to 8in 1987 with a minimum of 5 and 4 pairs in 1983 and 1984, respectively (Rasmussen and Storgard 1981). In Germany and Denmark, minimum figures were nearly parallel during 1983-5. These years were characterized by extremely bad weather with high rainfall during May (1983 and 1984) and June (1985). Nevertheless, the Netherlands study areas showed only very small declines in numbers of pairs during these years. Probably the dry and sandy soils in these areas had a positive effectwhile especially in Germany the moist soil in the nesting territories was soake

d and parts of the woodland were flooded. (Studies with less than 100 pair-yearsor less than 10 years were not included.)Population DensityDespite large-scale counts or estimates, there is also a requirement for densityfigures for suitable habitat or for whole landscapes of several hundred square

kilometres in size. The mean size of woodland per pair was c. 1000 ha (23 areasin central Europe: Kostrzewa 1985, Table 2). Data from 48 different sources gavea mean density of 4.52 + 5.37 pairs per 100 km2 and a median of 2.57. However,

small areas were greatly over-represented in this sample. Nine areas were smaller than 50 km2 and three smaller than 100 km2, totalling up to 25% of all areas checked, while mean size was c. 200 km2. A log-corrected value gave a more realistic density figure for large areas of c. 1 pair per 100 km2 (Kostrzewa 1991a) (Fig. 5). This is much less than the density of Goshawks (2.0 pairs per 100 km2) o

r Common Buzzards (14.0 pairs per 100 km2) estimated by similar methods (Kostrzewa and Speer 1995, Table 19).Numbers

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Britain8-15 pairs in 1980s. Increasing during 1990s, now 50-60 pairs (Roberts et al., 1999).France8000-12 000 pairs. Belgium. 300-450 pairs in 1989-91; increase?Luxembourg100-150 pairs in 1993.

Netherlands630-760 pairs in 1985-92 (Bijlsma et al. 1993).Germany3600 pairs in the early 1990s (Kostrzewa and Speer 1995) or 3800 (Mebs 1994). Data in Rheinwald (1993, old atlas) of 7700 overestimate the population by not taking too small census areas into account.Denmark600-700 pairs in 1988.Norway500-1000 pairs in 1970-90.Sweden5000-10 000 in the late 1980s.

Finland4000-8000 pairs in the late 1980s.Estonia600-1000 pairs in 1991.Latvia1500-2500 pairs in 1980s.Lithuania130-160 pairs.Polandc. 2500 pairs in 1990 (after Mebs 1994).Czech Republicc. 700 pairs in 1990 (after Danko, Hudec, and Mrilik in Mebs 1994).Slovakia

700-1000 pairs in 1973-94, another estimate is c. 800 in 1990 (see Czech Republic).Hungaryc. 300 in 1993 (after Haraszthy in Mebs 1994).Austria1500 pairs in 1993 (A Gamauf).Switzerland500 pairs in 1990, declining (Schmid 1990).Spain1000-2000 pairs 1980s to early 1990s.Portugal10-100 pairs in 1989.Italy500-800 pairs in 1983-93.Greece300-500 pairs (perhaps more).AlbaniaPerhaps 10-100 pairs in 1963.Yugoslavia: CroatiaPerhaps 150-250 pairs.Yugoslavia: Slovenia600-800 pairs.Bulgaria50-100 pairs; decreasing?Rumania

At least 100-250 pairs in 1986-92.Russiac. 100 000 pairs; stable or locally increasing?

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Belarus900-1000 pairs in 1990.Ukraine320-350 pairs in 1988; slightly decreasing?Moldovia30-50 pairs in 1989; slight decline?Turkey

50 pairs. These counts and estimates add up to a minimum figure of 135 188 and amaximum of 153 385 pairs (cf. Movements).

Conservation (New section)Hunting has been reported as a main threat along the migration routes for many years. There are reports from Orgambideska Pass (France); Strait of Messina (Italy; Giordano 1989); Lebanon and other countries around the Mediterranean, where hunting and poaching have a long tradition. Because existing legislation to protect raptors cannot be enforced in most countries, the main threat is still shooting on migration (Bijlsma 1987). Another serious threat is the rapid progress inhabitat destructionespecially of rain forestin western Africa (Kostrzewa and Speer1995). In European breeding grounds raptors are still illegally hunted [Bijlsma

et al. (1993) found most birds were shot in The Netherlands] or poisoned. Tjernberg and Ryttmann (1994) presumed that hunting lowered survival of Swedish birdssignificantly. For a stable population a recruitment of 0.67 young per pair peryear was required, but without hunting this could by lowered to 0.34 keeping a

stable population. Honey Buzzards are also sometimes shot from their nests whenconfused with young Goshawks (A Kostrzewa).Probably little affected by organochlorine pesticides. Four eggs from Belgium (1969-74) showed low contamination (p.p.m., dry mass: HCB 0.05, Lindan 0.15, DDE 0.35, PCB 3.0, HE 0.3, Diel 0.2; Joins and Delbeke 1981), as did four eggs from the Rhineland (p.p.m., dry mass: HCB 0.037, Lindan traces, DDE 1.06, PCB 6.36, HEnil, Diel nil, data 1981-2, two unsuccessful nests; Kostrzewa 1984). It is prob

able that PCBs were increasing during the 1970s and early 1980s as in most raptor species.