2009: Soil Organisms

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We test the hypothesis that the relative sizes of the different parts of the brain (brain stem, optic lobes, cerebellum and cerebral hemispheres), measured after body size effects have been removed, are associated with differences in behaviour and ecology across bird species. Tools are traditionally defined as objects that are used as an extension of the body and held directly in the hand or mouth.

Comparisons between myriapod assemblages at mine sites in Upper and Lower Lusatia that had different soil and age conditions revealed that myriapods are good indicators of biological soil quality and are reliable and easy to use. Using soil sampling and subsequent heat extraction of animals, four alder stands in the wetlands of the Biebrza, Narew and Bia³owieŜa national parks, north-eastern Poland, were surveyed for millipedes and centipedes. Among 12 millipede species revealed, Xestoiulus laeticollis, Polydesmus complanatus and Craspedosoma rawlinsii occurred and predominated in all alder woods.

Innovation rate is the best predictor of borderline tool use distribution. Despite the strong concentration of true tool use cases in Corvida and Passerida, independent constrasts suggest that common ancestry is not responsible for the association between tool use and size of the neostriatum and whole brain.

We draw attention to the high degree of inconsistency among empirical findings relating interindividual variation in innovativeness to interindividual variation in learning performance. We go on to propose a model that reconciles the possible (but perhaps controversial) existence of positive associations between cognition and innovation at the cross-taxon level with inconsistent associations at the within-species level.

When a value shifts substantially out of its reference range, a change of the system state is probable, especially if this applies for two or more parameters simultaneously. Three examples are given for considerable changes of the annelid community due to land-use change or natural succession. The detection of substantial changes of the community is based mainly on the species composition, but is supported by quantitative parameters using the reference ranges.

Karger AG, Basel. A further intensive study was made with millipedes and centipedes which need – like earthworms – a longer time for immigration.

The centipede fauna was very poor, altogether represented by four species, only Lithobius curtipes being shared by all sites. The myriapod communities from the swampy alder woods (Ribeso nigri Alnetum) at Biebrza and in the Bia³owieŜa Primeval Forest were mainly under the influence of fertility soil parameters (available and total phosphorus contents) while the assemblage from an alder swamp at Narew was largely affected by soil humidity. Apparently, the community from an ash-alder alluvial wood (Fraxino-Alnetum) sampled in the Bia³owieŜa Primeval Forest mostly depended on soil pH. Comparing all available information, the structure of myriapod assemblages seems to be quite similar even over distant regions in Central Europe.

Manakin displays vary across species in terms of behavioural complexity, differing in number of unique motor elements, production of mechanical sounds, cooperation between displaying males, and construction of the display site. Historically, research emphasis has been placed on neurological specializations for vocal aspects of courtship, and less is known about the control of physical, non-vocal displays. By examining brain evolution in relation to extreme acrobatic feats such as manakin displays, we can vastly expand our knowledge of how sexual selection acts on motor behaviour.

gerd knaebe

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