Early-life behaviour predicts first-year survival in a long-distance avian migrant

Early-life conditions have critical, long-lasting effects on the fate of individuals, yet early-life activity has rarely been linked to subsequent survival of animals in the wild. Using high-resolution GPS and body-acceleration data of 93 juvenile white storks (Ciconia ciconia), we examined the links between behaviour during both pre-fledging and post-fledging (fledging-to-migration) periods and subsequent first-year survival. Juvenile daily activity (based on overall dynamic body acceleration) showed repeatable between-individual variation, the juveniles'' pre- and post-fledging activity levels were correlated and both were positively associated with subsequent survival. Daily activity increased gradually throughout the post-fledging period, and the relationship between post-fledging activity and survival was stronger in individuals who increased their daily activity level faster (an interaction effect). We suggest that high activity profiles signified individuals with increased pre-migratory experience, higher individual quality and perhaps more proactive personality, which could underlie their superior survival rates. The duration of individuals’ fledging-to-migration periods had a hump-shaped relationship with survival: higher survival was associated with intermediate rather than short or long durations. Short durations reflect lower pre-migratory experience, whereas very long ones were associated with slower increases in daily activity level which possibly reflects slow behavioural development. In accordance with previous studies, heavier nestlings and those that hatched and migrated earlier had increased survival. Using extensive tracking data, our study exposed new links between early-life attributes and survival, suggesting that early activity profiles in migrating birds can explain variation in first-year survival.     

The people of Jabuticabeira II: reconstruction of the way of life in a Brazilian shellmound

Sambaquis are huge shellmounds built along almost the entire Brazilian coast between 8000 and 600 years ago. In the present article, 14 osteological markers from 89 individuals excavated at the Sambaqui Jabuticabeira II (2890±55/2186±60 BP) are analyzed in order to reconstruct the population′s health status and way of life. The present palaeopathological findings (such as lower frequency of degenerative joint diseases in legs, as compared to arms, and the rarity of traumas) together with archaeological findings support the idea of nearby resource abundance and infrequent interpersonal competition. The presence of auditory exostoses mainly in males corroborates previous findings indicating the importance of marine resources. The low caries frequency and the high degrees of dental wear point to a diet poor in cariogenic food, and rich in abrasives such as sand, shell fragments and phytoliths. This suggests a broader diet, based on marine protein as well as plants, than previously thought. The etiology of cribra orbitalia could be explained by gastrointestinal parasites or other sources of physiological stress. These parasites, in turn, could have led to higher frequencies of infectious diseases, either by the debilitation of the immune system or by the direct contact with infectious agents. Despite the periods of illness various individuals experienced, the daily life among the builders of the Sambaqui Jabuticabeira II seems to have been relatively easy due to the abundance and predictability of resources and the paucity of violent traumas.     

Echo 9 virus-induced order-disorder transition of chemotactic response of human polymorphonuclear leucocytes: phenomenology and molecular biology

By means of functional, morphological, and biophysical methods the in vitro interaction of Echo virus, type 9, strain A. Barty with human polymorphonuclear leucocytes (PMNs) was investigated and analyzed by statistical methods. Control cells and virus-treated PMNs (15 min, 37 degrees C; PMN: virus (pfu)-ratio ranging from 1:1 to 1:50) were exposed to a chemotactic gradient (N-formylmethionyl-leucylphenylalanine = f-Met-Leu-Phe, 10(-8) M/mm) in a Zigmond chamber. Whereas the track velocity of the moving PMNs was not affected by the virus, the degree of orientation of virus-treated PMNs declined in a way dependent on the viral dose and on the time of PMN:virus interaction, resulting in a shift from chemotactic to chemokinetic response. This virus-induced order-disorder transition of chemotactic response can be described by a logarithmic law in analogy to the Weber-Fechner law. Parallel to the functional disturbances, virus-induced changes of cell shape, which could be confirmed by additional light and electron microscopy techniques, were also detected using statistical analysis of cytological data (median cell size, anisotropy of cell shape) by means of two-dimensional histograms. To investigate f-Met-Leu-Phe- or/and Echo 9 virus-induced PMN-cell membrane changes, the monomer-excimer technique with pyrenedecanoic acid as fluorescent probe was applied, which gives information about structural changes of the cell membrane. Addition of the chemotactic peptide (10(-8) M) to control PMNs resulted in a higher rate of excimer formation obviously due to the formation of new functional (receptor) units (= activated cell membrane). Echo 9 virus exhibited an opposite effect. Quantitative analysis of these results revealed that the f-Met-Leu-Phe-induced cell membrane changes were extinguished by the addition of 2 pfu Echo 9 virus. So far, we have additional indicators of a virus-induced order-disorder transition of chemotactic response of human PMNs on a molecular biological level.     

Versuche über das Gehör der Noctuiden

Ohne Zusammenfassung     

Dosage effect study of the microsporidian Octosporea muscaedomesticae in the adult black blowfly Phormia regina,with reference to the reproductive cycle of the pathogen

The quantitative pathogenicity of the microsporidian Octosporea muscaedomesticae in adult Phormia regina was studied. Dosage levels ranging from 10² to 10⁶ spores per fly were administered to five and six groups of newly emerged, starved adult flies in two trials. Rates of mortality and infection were determined. A direct relationship between number of spores ingested and subsequent infection rate was found in a 4-day trial while no such relationship was found in an 18-day trial, using the same source of inoculum and host flies from the same colony. The lack of a direct relationship between spore dose and rate of infection in the 18-day trial is explained on the basis of the short spore-to-spore development time of the parasite. New generations of spores formed within the host tissues obscure the results in relation to the spore dose initially administered. An appreciable number of spores in the inoculum is needed to initiate frank infection. The ID₅₀ (median infective dose) was 4.4 × 10⁴ spores per fly after 4 days.     

Zur Bewegungsphysiologie der Nemertinen. I. Emplectonema

Ohne Zusammenfassung     

Über die Morphologische Bedeutung des Leitbündelverlaufes in den Blüten der Rhoeadalen und über das Diagramm der Cruciferen und Capparidaceen

Ohne ZusammenfassungMit 16 Textabbildungen (38 Einzelbildern).Dissertation der Mathematisch-Naturwissenschaftlichen Fakultät der Hamburgischen Universität.