Journal für Ornithologie

In January 1994 observations ofPhoenicurus ochruros on Majorca and investigations of its food indicated that wintering Black Redstarts are not as frequent as expected and show an irregular distribution pattern. Occurrence is concentrated along areas of coastal cliffs chiefly in the NE of the island. The food consists predominantly of small prey and a large portion of vegetable matter (berries of the mastic treePistacia lentiscus). It is presumed that Majorca does not provide attractive food conditions for wintering Black Redstarts. Beobachtungen vonPhoenicurus ochruros auf Mallorca im Januar 1994 und Untersuchungen seiner Nahrung brachten diese Ergebnisse: Überwinternde Hausrotschwänze sind nicht so häufig wie erwartet und sehr ungleichmäßig verteilt; Vorkommen konzentrieren sich in felsigen Küstenabschnitten, vorzugsweise im NE der Insel. Die Nahrung ist gekennzeichnet durch übermäßig kleine Beute und hohen Anteil pflanzlicher Kost (Beeren vonPistacia lentiscus). Es wird angenommen, daß Mallorca keine optimalen Nahrungsbedingungen für überwinternde Hausrotschwänze bietet.

A population of Garden Warbler was studied in a natural habitat in the Urseren valley (1500 m a. s. l.) for 7 years. The aim of this study was to describe the migration phenology and to evaluate if a self-sustainable population of this long distance migrant can exist under unfavourable climatic conditions. In spring, the Garden Warblers arrive about 3 weeks later, but in late summer they leave their territories at the same time as their conspecifics in the lowlands. Possible consequences of the restricted breeding period for juvenile development and migration schedule are discussed. In the study area, a very high breeding density (25 territories/10 ha) was recorded. The birds show a remarkable breeding and natal site fidelity (48 % of adults and 6 % of nestlings returned the following year). The overall breeding success was 48 %. The main causes of failure were predation and bad weather events. The latter were responsible for the annual fluctuations of breeding success. In conclusion, this study confirms that self-sustainable populations of this long-distance migratory species exist in mountain habitats.

We report on some aspects of the breeding biology of the critically endangered Writhed-billed Hornbill (Aceros waldeni) on the island of Panay, Philippines. Observations were made at three nests during 1995–1997. Walling-in of the females commenced in the first week of March. One female remained incarcerated for 77 days, two of three broods completed fledging around May 20 (1995, 1997). Details on fledging of the female and her brood and postfledging care by both parents are reported. The food of the males at two nests was ca. 98% fruits and 2% invertebrates. The plants exploited comprised at least 14 species. Over a third of the fruits delivered were figs of a small number of species. Two males had average feeding rates of 0.56 and 0.88 times per hour respectively, and fed 1 to 66 (median 8) items per feeding visit at the nest. The hourly feeding rate increased after hatching, but the composition of the diet did not change noticeably. As a rule, food items were delivered singly and, during one visit, in runs of one, or rarely up to 3, species. In the three weeks following vacation of the nest, the male appeared to be the sole food provider while the female stayed continually with the 3 young (as sentinel?) in the vicinity of the nest. The nest environs were defended by the male against Tarictic Hornbills (Penelopides panini panini). Six vocalisations of the parents are mentioned. One was used in territorial skirmishes with Tarictic Hornbills. With perhaps less than 30 pairs of the Writhed-bill surviving, the future for the species looks bleak. Only drastic conservation measures can prevent the species' demise. Some have been started by the PESCP.

Ringfunde und Kontrolle von farbmarkierten Eleonorenfalken ergeben, daß Eleonorenfalken-♀ in ihrem 2. Lebensjahr erstmals brüten und dann bereits 30% der Brutpopulation stellen. Sie besetzen jedoch schlechtere Brutplätze als ältere Falken- ♀ und haben einen geringeren Bruterfolg.