Exploratory behaviour plays an important role in most animals for gathering information about their environment. If it constitutes an adaptation to different environmental conditions exploratory behaviour should differ between species. This has been tested with several hypotheses. Sixty‐one parrot species (Psittacidae) from eight tribes with different diets and habitat preferences were investigated in aviaries. Two tests were carried out. First, a novel object (wooden ring) in the familiar aviary was presented on two test days in the exploration test. Latencies until first contact with the object and the duration of exploration were recorded. Secondly, in the neophobia test, novel objects were placed beside the feeding dish and latencies until first food intake were recorded. The exploration and neophobia data were related to 12 (13) ecological variables using multiple regression analyses. Phylogenetic relationships were considered. Species that inhabit complex habitats, such as forest edges, or that feed on buds or species from islands showed the shortest latencies in the exploration test. In contrast, long latencies were related to a diet including a great amount of seeds and/or flowers. The longest duration of exploration occurred in species eating nuts or originating from islands, whereas short durations were related to feeding on seeds. Neophobia was positively related to a diet consisting of insects, and negatively to a diet of leaves. There was no relationship between measures of exploration and neophobia. Exploration and neophobia seem to be tightly related to the ecology of a species.

The global prevalence of red and black fruits has still not been explained. Hypotheses based on innate consumer preferences have been tested and rejected. Though colour itself plays an important role in animal foraging, it is only one component of signals.Another major component are colour contrasts against background achieving the conspicuousness of signals. In order to evaluate which signal component determines consumers behaviour, we measured fruit colour and colour contrasts of 43 species against their natural background under ambient light conditions. Red and black fruits exhibit stronger contrasts and are therefore more conspicuous to consumers than fruits of other colours. Subsequently, trials were carried out to determine whether colour or conspicuousness influences avian food choice. Four bird species strongly preferred contrasting red Á/green or black Á/green over uni-coloured red, green, or black fruit displays, while no preference for particular hues was found. We therefore hypothesize that conspicuousness determines avian food selection and define the contrast hypothesis: Diurnal dispersers select fruit colours based on their conspicuousness and not their colour itself.Because colour vision is an ancient trait, the entire heterogeneous group of frugivorous birds most likely perceives conspicuousness uniformly over evolutionary time spans. Conspicuousness has thus the potential to explain the global prevalence of red and black fruits.

Haring, E. (2006). A preliminary revision of the genus Plecotus (Chiroptera, Vespertilionidae) based on genetic and morphological results.-Zoologica Scripta , 35 , 187-230. The phylogenetic relationships within the genus Plecotus were assessed using molecular as well as morphological methods. With only three species missing, our study is based on an almost comprehensive taxonomic sampling. The genetic analysis comprised 151 individuals from throughout the range. Sequences of two mitochondrial sections, parts of the 16S rRNA gene (16S) and of the control region (CR) were analysed. The morphological analysis of cranial and external characters comprised 697 individuals, including 10 holotypes and one lectotype. Data from 15 craniometric characters of 442 specimens were used in the multivariate analyses. The molecular data identified nine primary clades representing 11 species, 10 of which could be assigned to described taxa, whereas one was described as a new species, Plecotus strelkovi Spitzenberger sp. nov. The tree based on 16S revealed two major lineages, one consisting of only one primary clade restricted to the Mediterranean, the other consisting of eight primary clades representing Eurasian taxa. The morphological analysis revealed five additional species, two of them not described. Together with the recently described P. taivanus , P. sardus and P. balensis , which were not included in our analysis, the genus Plecotus comprises at least 19 more or less cryptic species. Phylogenetic and phenetic analyses resulted in similar but not completely concordant arrangements of the species. The proposed classification relies mainly on the tree based on 16S sequences. The current distribution indicates that 16 species can be linked to arboreal refugia, three to eremial refugia. We assume that speciation within the gleaning, rather slow flying long-eared bats is due to a multitude of disruption and isolation processes within a formerly continuous range of the broad-leaved Arcto-Tertiary forest in which Plecotus probably originated. An exact calibrated molecular dating of the splits is not possible. The Early Oligocene age of the presumed ancestor of the Plecotini and a correlation of the molecular diversifications with palaeogeographic reconstructions suggest that the divergence of the two major lineages may have occurred already during the Middle Miocene, 14.5 Mya.

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2003. Testing the defence trade-off hypothesis: how contents of nutrients and secondary compounds affect fruit removal. -Oikos 102: 318-328.Fruit removal has been attributed to the contents of nutrients and secondary compounds. We tested two alternative models of the chemical defence of fruits for the contents of nutrients, phenols, and condensed tannins and the nutrient content pypothesis stating that nutrient rich fruits are preferably removed. The defence trade-off hypothesis assumes that the retention of deterrent secondary metabolites in ripe fruits reflects a trade-off between defence against pests and attraction of dispersers. The removal-rate model of this hypothesis predicts a negative relationship of nutrients and levels of secondary compounds due to short persistence and thus low infection risk of fruits. The nutrient-toxin titration model postulates a positive relationship assuming that profitable fruits are able to afford high levels of protection due to a compensatory effect of high nutrient levels for consumers. Fruit removal by the entire frugivorous community for 33 plant species was best described by a dose-response curve, mediated by the stimulating effects of lipid, carbohydrate, and nitrogen contents, while the contents of phenols and water deterred removal. Moreover, traits that stimulated removal prevailed in ripe fruits except for nitrogen, unripe fruits had higher contents of phenols and nitrogen. Profitable fruits were quickly removed and had low phenolic contents. Thus, fruit removal was characterised by the nutrient content hypothesis and pulp contents by the removal-rate model. The selective pressure of 84 frugivorous species integrated into an unidirectional preferential removal of nutrient rich fruits. The consistency of consumers' preferences implies the potential for habitat shaping processes due to differential recruitment of plant species based on dispersers' choices.