Anwendung der Hasse-Diagrammtechnik

Using four dynamic criteria, the following environmental changes were evaluated: Global warming; destruction, of the stratospheric ozone layer; eutrophication and acidification of aquatic ecosystems; photochemical smog; reduction of the available area of agricultural soils; loss of species diversity; consumption of resources; reduction of crop yield; forest decline; noise, and smell. These ecosystem changes, or negative effects, were characterized by four dynamic criteria: 1) Regional importance, 2) extent of alteration, 3) resilience and 4) irreversibility. A multi-criteria assessment, accounting simultaneously for all four criteria, requires a generalized concept of order. Here, the concept of partially ordered sets, visualized by Hasse diagrams, was used to derive a priority list of environmental changes. Highest priority was equally assigned to the loss of species diversity, the consumption of resources and the destruction of the ozone layer. However, these ecosystem changes are incomparable to each other concerning the four criteria used and thus require different management strategies.     

Shoaling decisions in three-spined sticklebacks (<Emphasis Type="Italic">Gasterosteus aculeatus</Emphasis>)—familiarity,kinship and inbreeding

Shoaling with familiar kin is a well-known phenomenon. It has been described both for adult and for fry of three-spined sticklebacks (Gasterosteus aculeatus). However, evidence of preference for kin independent of familiarity is scarce. Furthermore, inbreeding effects have not been studied for shoaling preferences and there is a lack of studies about changes in individuals’ ability to recognise kin during different phases of life history. We gave inbred and outbred, nonreproductive sticklebacks of different age the choice to shoal with a group of familiar siblings vs unfamiliar non-siblings and with unfamiliar siblings vs unfamiliar non-siblings. Subadult sticklebacks preferred to shoal with familiar kin over unfamiliar non-kin, but inbred and outbred individuals had similar preferences. When given the choice between unfamiliar siblings and unfamiliar non-sibs, adult outbred fish preferred the shoal of kin, while inbred fish behaved indifferently. Body characteristics of the group such as body mass, standard length and condition of its members did not significantly explain the shoaling preferences for kin. Thus, sticklebacks were capable of recognising familiar and unfamiliar kin. The latter capability was lost by inbreeding.     

Can faecal glucocorticoid metabolites be used to monitor body condition in wild Upland geese Chloephaga picta leucoptera?

The measurement of faecal glucocorticoid metabolites is used as a non-invasive technique to study stress in animal populations. They have been used most widely in mammals, and mammalian studies have also treated issues such as sample stability and storage methods. In birds, faecal corticosterone metabolite (CM) assays have been validated for a small number of species, and adequate storage under field conditions has not been addressed explicitly in previous studies. Furthermore, while it is well-established that baseline plasma corticosterone levels in birds rise with declining body condition, no study so far investigated if this relationship is also reflected in faecal samples. We here present data of a field study in wild Upland geese Chloephaga picta leucoptera on the Falkland Islands, testing different storage methods and investigating the relationship of faecal CM concentrations to body condition and reproductive parameters. We found that faecal CM measures are significantly repeatable within individuals, higher in individuals with lower body condition in both male and female wild Upland geese and higher in later breeding females with smaller broods. These results suggest that measuring faecal CM values may be a valuable non-invasive tool to monitor the relative condition or health of individuals and populations, especially in areas where there still is intense hunting practice.