Mueller J.: Welchen Beitrag leisten Naturwaldreservate zum Schutz von Waldvogelarten? Near-natural Strict Forest Reserves: What do they contribute to the protection of woodland birds?

In Bavaria in 153 near-natural Strict Forest Reserves timber is not being used anymore. This report compares breeding bird communities of eight broad-leaved deciduous Strict Forest Reserves using data from quantitative raster mappings. Both the comparison of gildes and the ordination show a progression of the reserves along a gradient of their near-natural status. Old oak tree high forest stands and reserves with trees showing huge crowns of former coppice with a standard system in a landscape of deciduous woods are very close to natural conditions. Clearly reserves with a proportion of conifer trees in a landscape of coniferous forests are further away from natural conditions. Reserves dominated by beech show fewer indicators of near-natural status, where old growing trees are still missing. With an increasing degree of near-natural status also the species richness, shown in a Shinozaki graph, is also increasing. Judged by the degree of threat, reserves with a good near-natural status are also of high value to bird protection. Middle Spotted Woodpecker, Collared Flycatcher, and Pied Flycatcher with their high breeding densities proved to be appropriate indicators for near-natural broad-leaved woods. In the reserve "Eichhall" breeding densities of 2.6 pairs/10 ha were found for the Middle Spotted Woodpecker, 3.1 pairs/10 ha for the Collared Flycatcher and 6 pairs/10 ha for the Pied Flycatcher. Thus for the protection of woodland birds larger reserves with old and huge crowned oak trees in broad-leaved woods are most important, smaller reserves in conifer woods rather serve as stepping stones for the spread of rare birds.

For further information please contact: Joerg Mueller, Bayerische Landesanstalt für Wald und Forstwirtschaft, Am Hochanger 11, D-85354 Freising; e-mail: mue@lwf.uni-muenchen.de

Utschick, H.: Saisonale Veränderungen der Raumnutzungsmuster von mittelschwäbischen Waldvogelzönosen. Seasonal distribution pattern dynamics of a bird community in a Mid-Swabian forest landscape.

Combined grid (90 units of 6.25 ha) and polygon mapping (92 forest stands from 0.3 to 29.7 ha) of a bird community on 562 ha of a Mid-Swabian forest landscape (2 test areas of 250 ha each near Ettenbeuren/Krumbach and Oberschönegg/Ottobeuren; 1 area of 62.5 ha near Edelstetten, Southern Bavaria) was used to analyse the influence of stand composition and management intensity on the time-space-distribution of forest birds (time-standardized monthly counts; Mar 1999 to Feb 2000). Main results are:

• Bird communities of forest stands depend on stand characteristics and on the local character of the surrounding forest landscape as well. During the breeding period, stand characteristics (in small stands those of the neighbouring stands too) are more important. During summer (fledgling period) and autumn (migration) landscape variables like stand distribution patterns, and mainly in winter, the local space-pattern of climatic site-conditions strongly influence local distribution of forest birds.
• Habitat preferences of forest birds fluctuate within a year between nearly all stand classes (tree composition, age, structure, intensity of use) of the tested, very productive and heavily used forest area. Same was found at the tree species level, where the distribution pattern of large-dimensioned oaks, leaf trees (without beech) or larches is very important.
• In a managed spruce-dominated landscape mature nature reserves and similar broadleaved stands of sufficient size are necessary for a high bird species diversity due to founder population effects. At all seasons, such stands specially increase the value of local bird communities when situated on slopes with southern exposition at margins of extensive forest areas.

The consequences for using forest bird data in nature conservancy problems (for example in creating management strategies following an evaluation impact study or in planning the conservation and development of reserves) should lay emphasis on non-breeding aspects (at least winter aspects) and on forest characteristics at the landscape level (connectivity aspects at least at the km²-level). The most suitable method is a quantitative grid mapping with subunits (stand polygons within the grid), but this method has rarely been used to date due to difficulties getting comparable data standards at different landscape levels.
What is important for the forestry management in the Mid-Swabian, spruce-dominated forest landscapes, is that the time-space patterns, specially those of coniferous bird guilds, are well supported by the existing management system (Altersklassenwald) based on rotating qualities (time, space) of small sized forest stands (average 6 ha). But high bird community diversity can only be reached, if this system is be completed by a narrow grid of mature broadleaved stands or reserves (4-10 ha), especially on sunny slopes (very important mainly for winter birds) and at forest margins, and an enrichment of leave trees and larch within many spruce stands.

For further information please contact: Dr. Hans Utschick, Lehrstuhl für Landnutzungsplanung und Naturschutz, Am Hochanger 13, D-83354 Freising; e-mail: Hans.Utschick@lrz.tum.de

Reichholf, J. H.: Brut- und Schlafplätze hinter Wasserfällen: Evolutionsbiologische Betrachtung des außergewöhnlichen Verhaltens der brasilianischen Rußsegler Cypseloides senex.
Breeding and Roosting behind Waterfalls: Evolutionary Aspects of the Exceptional Behaviour of the Brazilian Great Dusky Swift Cypseloides senex

Great Dusky Swifts, Cypseloides (Aerornis) senex, nest and roost behind waterfalls in subtropical and tropical South America. This exceptional behaviour may not be simply the result of a step by step approach to the falls from the sides but it could be interpreted differently according to the ecological conditions during the Pleistocene era when water discharge of the rivers there was much lower than at present and also more seasonal. Swifts by their very nature have a number of predispositions for the use of waterfalls and coping with increasing amounts of water pouring over the falls should not have posed too big a problem for them. A striking convergence is found in the Southeast Asian Swiftlets of the Collocalia-group with the Waterfall Swiftlet Collocalia (Hydrochous) gigas, to which the evolutionary model presented here for the Great Dusky Swift is applicable likewise.

For further information please contact: Prof. Dr. Josef H. Reichholf, Zoologische Staatssammlung, Münchhausenstr. 21, D-81247 München; e-mail: reichholf.ornithologie@zsm.mwn.de

Nitsche, G.: Die Brutvogelfauna des Auer Weidmooses, Landkreis Rosenheim (Oberbayern): Langfristige Veränderungen und Effizienzkontrolle der Naturschutzgebiets-Ausweisung. The breeding bird populations of the Auer Weidmoos, district of Rosenheim (Upper Bavaria): Long-term changes and efficiency-control of the designation as nature conservation area.

Changes in the breeding bird population and their possible causes over 50 years in a fen in Upper Bavaria will be discussed. Furthermore, the consequences of the designation of a nature conservation area (NSG) in 1979 on the bird population after more than 20 years will be examined. The NSG contains a remaining part of the original moor (76.5 ha). Drainage and cultivation of the fen led to significant changes in the structure of the landscape with drastic consequences on typical bird species: Corncrake and Great Grey Shrike had very likely disappeared before the designation, the Black Grouse with certainty. For the Snipe this was the case after the designation as NSG, the remaining moor offers the Curlew suitable habitats for only two breeding pairs. In consideration of the successive dehydration of the fen area also other typical birds like Lapwing, Meadow Pipit and Whinchat also show decreases in their breeding numbers. The Teal lost its habitat because of succession processes in small peat banks. The disappearance of Golden Oriole and Common Whitethroat as breeding birds could be due to the location of the site at the border of their distribution ranges. For Grasshopper Warbler, Reed and Marsh Warbler as well as for the Reed Bunting no large population changes have been observed.
Waterfowl, which have colonized a new small fish pond, are Little Grebe, Tufted Duck and Moorhen. The immigration of the Stonechat has to be seen in the light of the recent expansion of its breeding range in Bavaria. The probable occurrence of the Woodcock was possible after the development of small woodlands. For the Quail the NSG represents an ideal habitat in the intensively used meadows around the area. It probably benefits from the designation of the NSG because of the regular biotope management. The increase in shrubs and trees by natural succession has probably led to an increase in songbird populations. In the light of the negative population development of the characteristic birds of fens and wet meadows, improvements of habitat management in the future are proposed. The focal point is re-wetting of parts of the fen.