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Black-billed Magpies possess distinctive patterns of black and white on their flight feathers which have been suggested to be family-specific. Such a phenomenon could potentially provide a simple field-method for recognising related or unrelated offspring. Using a combination of wing plumage patterns and multilocus DNA fingerprinting the relationship between plumage variation and genetic relatedness in the European Black-billed Magpie was investigated. The plumage of nestmates was more similar to each other than to young in other nests. However, extra-pair offspring could not be identified from nestmates through plumage differences. Within brood similarity may be explained by full-siblings sharing plumage characteristics through random inheritance, or through a shared rearing environment. Extra-pair offspring may resemble their half-sibs due to shared maternal plumage characteristics and a common rearing environment.
Acta Ornithologica
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1997
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tom 32
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nr 1
121-126
Magpie Pica pica is widely distributed over the built-up areas of Berlin. A population increase is observed at least from the 60s up to now. Over about 20 years population changes are documented in different parts of Berlin. Some main lines of increase are shown for two different habitat types: residential district and closed built-up zone of the city. The method of territory mapping was applied including search for nest stands. The population changes are different for both parts (less steep in the residential district). Recent abundances in the central block building districts exceed those from the residential districts, however, the new top number ist 32 p/km² for a high-rise building area. Since 1991, winter birds were censused in different habitats of Berlin since 1991, during the winter periods 1991 and 1992 with varying plot size, and from 1993 to 1995 on 5ha plots. Magpie uses the residential district with high frequency and abundance. There is some concern about comparability of abundances from winter and breeding seasons. The daily range of a roosting winter community of up to 420 birds is estimated at about 12 km², which means an abundance of up to 3,5 ind./10ha rather near to numbers found on 5ha plots, however, exceeding numbers expected from the breeding season. Henceforth, during winter time Magpies may prefer other habitat types than in the breeding season.
The Black-billed Magpie, Pica pica sericea, was introduced in Japan from Korea about 400 years ago. It inhabits a restricted area in northern Kyushu, but has relatively high nesting density in some areas (> 20 pairs per km²). Most nests are built in the vicinity of human habitation, even in the midst of cities. Most clutches are laid in March and April. Mean clutch size (6.2) and mean number of hatchlings (4.2) are within the ranges of values for European and North American races. Nesting success is low, with only 18% of clutches surviving to fledge. Predation, mainly by crows, is a major cause of failure, accounting for 81% of clutch loss and 84% of brood loss. Low nesting success may have taken place in recent years. Nests on utility poles are more successful than those in trees. Nesting on utility poles has been increasing, occupying more than 50% of total number of nests. The range of the Black-billed Magpie has been gradually expanding in Japan.
Research on the Magpie Pica pica was conducted in the limits of urbanized part of Lvov (66.5km2) in the summer of 1994-1995, and the winters of 1993/94 and 1994/95. The work was based on an ecological (landscape mosaic) division of the city. The number of breeding Magpies was estimated to be 520 pairs (0.8 pair/10ha). The highest density of birds was recorded in parks and areas of one family houses (1.2 pair/10ha), less in the modem housing estates (0.7 pair/10ha), and the lowest in the central and industrial districts (0.4 pair/10ha). The number of wintering Magpies in Lvov is about 2000 (3 ind./10ha). The highest density was recorded in rural zones of the town (8.4 ind./10ha), the least in the industrial zones (1.8 ind./10ha). In winter outside of the town Magpies were counted at a communal roost, which gathered up to 1700 individuals.
The height, chosen tree species and location of 1316 Magpie nests in 11 towns and 6 farmland plots were examined in 1992. t-tests revealed a difference significant at p < 0.001 for the heights at which nests were located, with those in urban areas (x̅ = 13.2m, SD = 3.7, N = 513) being higher than those in suburban areas (x̅ = 11.3, SD = 4.1, N = 232), those in villages (x̅ = 9.6, SD = 3.7, N = 433) and those on farmland (outside villages) (x̅ = 9.0, SD = 3.7, N = 138). The heights of nests in villages and on farmland outside villages did not differ significantly. The percentage distribution of chosen trees showed a predominance of similarities (using Renkonen's Index) for the biotopes compared: urban and suburban areas (Re = 73%), villages and farmland outside villages (Re = 77%). The percentage distribution of nest locations (single trees/shrubs, clumps of trees/shrubs, parks/cemeteries, gardens/orchards, avenues, rows of trees/hedgerows) also showed a predominance of similarities for urban areas, suburban areas, villages and farmland outside villages (Re values between 75% and 85%). The data indicate substantial ecological plasticity in the selection of nest sites by Magpies and suggest that differences are due to local variations in nesting habitat rather than real differences between urban and rural populations.
Magpie in Warsaw is sedentary and ubiquitous species inhabiting all types of urban habitats. This study (1986-1990) estimated the breeding population in the entire area of Warsaw (485km²) at 6-8 p./km², and in winter (on the area of plots 245km²) — at 11-17 ind./km². The frequency of distribution in both seasons was 92-93% in the whole area 92-93%, and 100% in the inner city plots. Density in the inner city (52km² —19 p./km², in winter — 29 ind./km²) was 3 times higher than in the outer urban zone (150km² — 7 p./km², in winter 54km² 11 ind./km²) and 4-5 times higher than in outskirts (283km² — 5 p./km², in winter 139km² — 6 ind./km²). Density of population in winter decreased on outskirts and increased in inner city areas. The highest abundance was in green riverside belt (24 p. and 38 wintering ind./km²), in housing estates (21-25 p., 32 ind./km²) and in city parks (20-23 p., 36-37 ind./km²). The lowest was in peripheral forest parks and agriculture areas (2-4 p., 4-7 ind./km²). Colonization of the inner Warsaw by Magpie began in 1950-ties. Since then its population in this area (52km²) increased from few pairs to 800-1200 pairs. It reached the position of subdominant in the bird community, and its success is probably most dynamic among all species of the avifauna of Warsaw.
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