Entwicklung der K?rpermasse nestjunger Braunkehlchen (Saxicola rubetra)

Zusammenfassung 1990–1992 wurden 106 Nestlingen zum Teil mehrmals gewogen (=274 Wägungen). Braunkehlchen schlüpfen mit einer Masse von etwa 2,0 g, nehmen täglich im Mittel 1,63 g zu und erreichen nach neun Tagen eine Körpermasse von 16,8 g. Die Ausfliegemasse lag zwischen 17 g und 19,5 g. Die Masseentwicklung in den ersten 10 Lebenstagen ließ sich mit einer logistischen Wachstumskurve gut beschreiben. Am 5. Lebenstag wurde mit 3,34 g die höchste tägliche Massezunahme erzielt. In den ersten fünf Lebenstagen nahmen Braunkehlchen täglich 40–50 %, danach nur noch 5–15 % der Körpermasse zu.

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Mass development of Whinchat nestlings (Saxicola rubetra)

Summary During 1990 and 1992 masses of 106 nestlings were measured with a Pesola spring scale once to five times (274 measurements). Hatching mass was 2.0 g, fledging mass 17 g to 19.5 g. Mass gained per day by 1.63 g and peaked 16.8 g after nine days. The mass development for the first ten days could be well described by a logistic growth curve (Fig. 3). The maximum daily mass gain was 3.2 g on day five. During the first five days mass gain was between 40 % and 50 % (except on day 4: 25 %), later on between 5 % and 15 % of the body mass. The data are discussed in relation to results from other ground nesting birds as well as to enlarged mortality rates in the first few life days of Whinchats.

     

Effects of changes in farming of subalpine meadows on a grassland bird, the whinchat ( Saxicola rubetra)

The increasing intensity of farming of meadows is supposed to be the major cause for strong declines of many meadow breeding birds. The whinchat, Saxicola rubetra, a Palaearctic migratory bird, is an indicator species of open grassland farmed at a low intensity. Originally widespread throughout Switzerland, it is now restricted to mountain and subalpine grassland. We document the changes in meadow cultivation in subalpine farmland from 1988 to 2002, and the breeding performance and density of the whinchat. We explored the impact of habitat degradation on the population dynamics of this meadow bird. The cultivation of hay meadows changed markedly within the 15 years: the onset of mowing was shifted forward by about 20 days, and farmers applied new techniques such as silage and irrigation. This shift was more pronounced in the favourable farmland in the valley bottom (Pradellas) than on the slopes (Vnà). The percentage of successful whinchat broods, ranging from 5% to 78% in different years, strongly depended on mowing date on both sites. In spite of earlier mowing, birds did not change their time schedule of breeding. Breeding success in Pradellas was too low to compensate for mortality (sink population), but because of immigration the number of breeding pairs did not decrease untill 2000. Population size may therefore be a misleading indicator of local population viability. Based on the breeding schedule of whinchats at different altitudes, we recommend mowing dates in agreement with the reproductive cycle of ground nesting meadow birds.     

Einflu? des Nestlingsalters auf die Nahrungszusammensetzung nestjunger Schwarzkehlchen (Saxicola torquata)

Zusammenfassung 1984–1986 wurden 654 Kotproben mit 3754 Beutetieren bei 1–14tägigen Nestlingen des Schwarzkehlchens gewonnen. Im Laufe der Nestlingszeit stieg die Anzahl der Beutetiere von 2,06 auf maximal 9,61 Individuen pro Kotballen an. Die Nahrung war altersabhängig verschieden zusammengesetzt. Der Spinnenanteil von ca. 50 % in den ersten Nestlingstagen sank gegen Ende der Nestlingszeit unter 10 %; der Anteil der Käfter stieg dagegen von 0 % bis über 50 % an. Eine Abschätzung der Biomasse unterstreicht die große Bedeutung der Raupen als Nahrung für alle Altersstufen. Ihr durchschnittlicher relativer Anteil von 23 % stieg auf 75 % an. Mit fortschreitendem Nestlingsalter stieg der Anteil hart chitinisierter Beutetiere, während der Anteil weich chitinisierter Beutetiere sank. Somit spielten gegenüber der leichten Verdaulichkeit die Abundanz und Erreichbarkeit der Beutetiere für die jagenden Altvögel eine immer größere Rolle.

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Effect of age on composition of the diet of nestling Stonechats (Saxicola torquata)

Summary 654 droppings of 1 to 14 days old nestlings were sampled during the breeding seasons 1984 through 1986 in a lowland valley in North-Rhine-Westfalia. The number of 3754 prey items could be verified. The number of prey item per dropping increased from 2,06 to the maximum of 9,61 during the nestling period. Diet composition changed significantly as a function of nestling age. The proportion of spiders of 50 % in the first days after hatching decreased to a proportion of 10 %, while coleoptera increased from 0 % to more than 50 %. The biomass was estimated for the main taxonomic prey categories. The result underlined the special importance of caterpillars as nestling diet over the whole nestling period. The average proportion of 23 % rose to 75 % with respect of the biomass. It could be demonstrated that the proportion of hard chitinised food increased with nestling age while the proportion of soft chitinised food decreased. As the nestlings grew older the abundance and availability of prey got more important for the hunting adult Stonechats than the easy digestibility of food.

     

Pratincola rubetra als Spottvogel

Ohne Zusammenfassung     

Whinchat Saxicola rubetra reproductive success according to hay cutting schedule and meadow passerine density in alluvial and upland meadows in France

In France, whinchat Saxicola rubetra populations now rarely breed at altitudes below 1,000 m except in flooded alluvial plains. Whinchat reproductive success, the timing of haymaking and meadow bird density were assessed in 2003 in six areas selected in three different flooded plains, in five areas from two massifs at altitudes ranging from 990 to 1,250 m, and in 2004 in six areas of three flooded plains, in seven areas from three massifs at altitudes ranging from 1,200 to 2,000 m. The percentage of whinchat territories in which juveniles were observed was negatively correlated with mown areas at the time when 80% of hatched broods (observation of prey carryings by adults) would theoretically be fledged. Additionally, assessed hatching success was negatively correlated with early haymaking in 2003 and with meadow passerine territory density in 2004. In upland meadows, whinchat populations exhibited either low reproductive success and low density (1,200 m) or high reproductive success and high density (1,200 m). In lowland flooded meadow however, high density could match low reproductive success and whinchat population then acts as a sink population. We conclude that adequate agri-environmental policy should not focus only on lowland meadows, even if the highest meadow bird diversity is often found there.     

Revierbesetzung, Reproduktion und menschliche Verfolgung in einer Population des HabichtsAccipiter gentilis

In southern Bavaria all GoshawkAccipiter gentilis territories were checked in an area of 6690 km² during a long-term study. The number of breeding pairs fluctuated within short periods, the percentage of females breeding only once increased. 1989–1997 the number of breeding pairs decreased from 83 to 34. The average annual reproduction was 1.59 per female, for females breeding once 1.14, for females breeding at least in two (up to 12) consecutive years 2.04. The lifetime reproduction per female was 2.44. Among 489 females 21 % had no offspring, whereas ca. 16 % produced 50 % of the total offspring (including single females with more than 20 fledglings). Sex ratio among nearly fullgrown nestlings was balanced, varying with annual reproduction rate. The breeding population suffers from modern forestry management and regular persecution particularly in areas with released Pheasants. Regional differences in turnover among territorial Goshawks and reproduction rates could be mapped. Core areas for the population form only minor parts of the area inhabited by breeding Goshawks.     

Brutzeit und zeitliche Verteilung der Bruten einer Population der Ringeltaube (Columba palumbus)

Zusammenfassung Von einer kleinen in Straßenbäumen nistenden Population in der Agrarlandschaft bei Braunschweig wurden 1961–65 sämtliche Bruten erfaßt.Die Legezeit erstreckte sich von (April) Mai bis September, wobei 69% (s=13,2%) der Gelege (n=106) in den Monaten Juli—September begonnen wurden und der Juli in allen Jahren Maximum und Median aufwies.Es besteht Übereinstimmung mit den umfassenden Ergebnissen an englischen Ringeltauben (Murton). In Deutschland wurde der Schwerpunkt der Legezeit mit Mai-Anfang Juli (Niethammer 1942) bisher allgemein zu früh angenommen.

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Breeding season and distribution of egg-laying in a population of Woodpigeons(Columba palumbus)

Summary A small population nesting in roadside trees in rural country near Brunswick, Northern Germany, was studied from 1961 to 1965.Egg-laying occurred from (April) May to September. However 69% (s=13,2%) of all clutches (n=106) were started in the second half of the period (July–September).There is large correspondence with the findings ofMurton in England. In Germany up to now, egg-laying was thought to take place mainly from May to early in July. It is pointed out, that this view was caused by the lack of quantitative studies.

     

Materialien zu einer Revision des GenusCampephaga Vieill

Ohne Zusammenfassung     

Gonadal status upon spring arrival in long-distance and short-distance migrating stonechats (Saxicola torquata)

Long-distance migration is often associated with relatively short breeding seasons and a start of reproductive activities shortly after arrival. The full activation of the reproductive system from the regressed state takes, however, several weeks and must, therefore, be initiated in the winter quarters or during spring migration. Hence, long-distance migrants face a potential conflict between the energetic and temporal requirements of migration and the preparation for reproduction. We studied long-distance migratory Siberian stonechats in northern Kazakhstan and short- distance migratory European stonechats in Slovakia. We hypothesized that migratory distance and gonadal status at the time of arrival are related. We found that males of both populations arrived with gonads that were not fully developed. However, the populations neither differed in gonadal state at the time of arrival, nor in the rate of testicular development to the fully active state at the time of egg laying. The rate of the last stages of gonadal development may be determined by physiological constraints rather than by a trade-off between migration and reproduction. Within populations, passage migrants and local breeders could not be distinguished on the basis of their testicular development. However, passage migrants showed higher variation in gonadal size than local breeders, which could relate to the differences in migratory distance and hence reproductive timing.     

Untersuchungen an einer stabilen Neunt?terpopulation(Lanius collurio)

Ohne Zusammenfassung     

Social foraging and habitat use by a long-distance passerine migrant, Whinchat Saxicola rubetra, at a spring stopover site on the SE Adriatic coast

The preference for foraging in groups and the effect of physiognomic factors of a habitat on its use by foraging Whinchats (Saxicola rubetra) was studied during spring migration stopover in a mosaic cultural landscape at the SE Adriatic coast. Every record of spatially distinct Whinchats, either a solitary individual or a group, was referred to as a Whinchat unit. The units were classified as intensively foraging, less intensively foraging or non-foraging and divided into four size classes. The effect of physiognomic habitat factors on use of habitat by foraging Whinchat units was modelled. All possible additive models using logit link function were constructed from five independent physiognomic variables: (1) natural perches (NP), (2) artificial perches (AP), (3) high herbal vegetation (HHV), (4) open bushes (OB) and (5) heterogeneity of vegetation types (HVT). Variables HHV and OB were included simultaneously in the models. Models that were substantially supported by the data were selected according to second order Akaike’s information criterion AIC_c. Two such models contained variable(s) (1) NP and (2) NP + AP. The relative importance weights of physiognomic variables NP, AP, HVT, HHV and OB were 1, 0.38, 0.24, 0.13 and 0.13, respectively. Perches were thus the most important physiognomic habitat factor affecting habitat use by Whinchats in a mosaic cultural landscape. The great majority of Whinchats foraged in groups and the proportion of intensively foraging Whinchat units increased with unit size, leading to the conclusion that Whinchats preferred social to solitary foraging on the spring stopover at the SE Adriatic coast.     

Freilandbeobachtungen und Versuch einer Bestandsaufnahme des Bali-StarsLeucopsar rothschildi

Zusammenfassung Der Bali-Star kommt heute nur mehr in einem 10 000 ha großen Rückzugsgebiet an der NW-Küste Balis (seit 1970 Naturschutzgebiet) vor. Der Bestand ist auf sicher weniger als 1000 Tiere zusammengeschmolzen und wird sich unter den gegenwärtigen Bedingungen auch nicht erholen, sondern eher zurückgehen. Erhaltungsmaßnahmen könnten erfolgreich sein, verlangen jedoch eine völlige Umstrukturierung des betreffenden Landstriches von einem ökonomisch genutzten zu einem echten Schutzgebiet.

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Some observations on the White Bali Mynah(Leucopsar rothschildi) in its natural environment

Summary The White Bali Mynah today is only living in a small area on the north-eastern coast of Bali; its number has decreased to utmost 1000 individuals and it has disappeared in great parts of its former habitat mainly due to human overpopulation. A conservation program for this species only will be successful if circumstances would change positively for the whole fauna and flora in the protected area called Nature Reserve Bali Barat.

     

Studien anLaburnum Adami

Ohne ZusammenfassungMit 21 Textfiguren.     

Die Jugendmause europ?ischer und afrikanischer Schwarzkehlchen (Saxicola torquata rubicula undaxillaris) sowie von F1-Hybriden

Summary In a constant 12 h, 50 min equatorial photoperiod postjuvenile moult started earlier and lasted shorter in European stonechats than in their African conspecifics. F₁-hybrids showed an intermediary time course of moult indicating that the differences found between these two subspecies are genetically determined.     

DieMusophagidae. Monographische Studien

Ohne Zusammenfassung     

Phylogenetisch-systematische Studien an Bombyliiden (Diptera)

For the first time 16 subfamilies (26 genera) of the Bombyliidae are analyzed for their phylogenetic relationship, using the egg-laying system as principal criterion. It is concluded that the generally held division of the family into two subgroups should be abandoned, because a monophyletic group is only represented by the B. tomophthalmae. The assemblage of all Bombyliidae possessing a soil chamber to coat the eggs is proposed as B. psammophoridae.     

Der Flug des Nektarvogels (Cinnyris)

Ohne Zusammenfassung     

Habitatwahl des Baumpiepers (Anthus trivialis)

Zusammenfassung 1975–1985 wurden die Habitat- und Nistplatzansprüche des Baumpiepers im Nordostteil des Kreises Soest/Mittelwestfalen (51° 40 N/08° 25 E) in 493 Revieren und an 141 Nestern analysiert. Der Baumpieper toleriert maximal eine Baumschichtdeckung <=80 %; 88,4 % der Reviere weisen Deckungsgrade von <=60 % auf. Baummischbestände verschiedener Altersklassen werden gemieden. Reviere mit einem hohen Eichenanteil werden bevorzugt. 80 % weisen Strauchschicht-Deckungsgrade <=30 % auf. Habitate mit einer Krautschicht-Deckung <50 % sind ungeeignet; in 50 % der Reviere deckte die Krautschicht >90 % der Fläche. Am häufigsten lagen Nester unter Bulten vonCalamagrostis epigeios (38 %) undBrachypodium silvaticum (37 %). Der Neststand wurde u. a. in Abhängigkeit von der Vegetationshöhe der Krautschicht ( =50,1±21,3 cm) ausgewählt. Nester waren bevorzugt in wetterabgewandter Richtung (ENE) exponiert, auf Freiflächen signifikant stärker als in geschlossenen Beständen. Nester lagen bevorzugt randnah. Abundanz und Krautschicht-Deckung waren positiv korreliert. In Jahren mit hoher Siedlungsdichte werden häufiger suboptimale Reviere besiedelt. Möglicherweise sind versteckte Nesteinpassung und mikroklimatisch günstige Nistplatzwahl in Verbindung mit ausgeprägter Brutpflege Ursache dafür, daß die Art einen höheren Bruterfolg als andere Pieper und viele Singvogelarten aufweist.

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On the habitat selection of the Tree Pipit (Anthus trivialis)

Summary In 1975–1985 the habitat- and nest site selection of the Tree Pipit (Anthus trivialis) was investigated in the NE of county Soest/central Westphalia (51° 40 N/08° 25 E). 493 territories and 141 nests were analysed. The Tree Pipit tolerates a canopy-cover of up to 80 % at a maximum; 88,4 % of the territories showed a percentage of cover of up to 60 %. The species avoids woods where the trees vary in age. Territories with a high percentage of oaks are preferred. Tree Pipit habitats are characterized by lower shrub; 80 % show a cover of up to 30 %. Habitats with field layer up to 50 % are unsuitable; in 50 % of the territories the field layer covered >90 %. The Tree Pipit breeds mainly under tussocks ofCalamagrostis epigeios (38 %) andBrachypodium silvaticum (37 %). The nest site is selected depending on the height of the field layer ( =50,1±21,3 cm). Nests are facing mainly ENE, this being the opposite of the main weather direction. This direction is more strongly preferred in clearings than in woods. Nests are built mainly in the vicinity of wood rows. The coverage of the field layer is positively correlated with population density. In years with a high population density less suitable territories are more often occupied. The combination of well hidden nests, suitable nest site selection, and highly developed parental care is possibly the reason that the Tree Pipit has a higher breeding success than other pipits and many other songbirds.

     

Taxonomic status and evolutionary history of the Saxicola torquata complex

We explored variation in mitochondrial ND2 gene sequences from 171 stonechats (Saxicola torquata complex) collected from 27 Eurasian and 3 African localities. We found that two widespread neighboring Eurasian subspecies of Siberian stonechat, Saxicola maura maura and S. m. stejnegeri, although very similar in appearance, are not each other’s closest relatives. Eastern Asian S. m. stejnegeri appears to have split from other Palearctic, African, and island stonechats well before differentiation occurred among the latter taxa. Our data indicate that European (S. t. rubicola), central Palearctic (S. m. maura) and eastern Palearctic (S. m. stejnegeri) are independently evolving, and could each warrant separate species status, as assumed earlier for S. rubicola, S. maura and S. torquata. However, we found three localities at which individuals from different major groups occurred. Thus, although these are likely phylogenetic species it is unclear whether they are biological species. There was little phylogeographic structure within the three major Palearctic clades, although samples from Spain might be showing incipient divergence. We maintain that the topology of a mtDNA gene tree is a valid means to discern taxonomic limits.