9 research outputs found
Morphology, geographical variation and the subspecies of marsh tit Poecile palustris in Britain and central Europe
Capsule: All British Marsh Tits belong to subspecies Poecile palustris dresseri, being smaller than nominate P. p. palustris of central Europe.
Aims: Determining the subspecies of Marsh Tit in Britain to test whether ssp. P. p. palustris occurs in northern England and Scotland, by assessing regional variation in size compared with central European birds.
Methods: 1147 wing length and 250 tail length measurements from 953 Marsh Tits were compared between eight British locations to test for regional variation. Biometrics were compared between birds from Britain and six locations within the continental European range of ssp. palustris.
Results: There was no regional variation in wing or tail lengths among British Marsh Tits, indicating that all resident birds belong to ssp. dresseri. There was no evidence supporting the existence of ssp. palustris in northern England. British birds were significantly smaller than those from continental Europe, with proportionately shorter tails, consistent across all age and sex classes.
Conclusion: All British Marsh Tits should be considered as ssp. dresseri, with ssp. palustris being limited to continental Europe. With no evidence of regional variation in size within Britain, reliable sexing methods based on biometrics could be applied in demographic studies throughout the country
Probability of TCD-Normalization in the “Drepagreffe” Trial Comparing Transplantation to Chronic Transfusion in Sickle Cell Anemia Children with Abnormal-Transcranial Doppler Is Associated with Lower Ang-2 and BDNF Plasma Levels.
CERVOXYInternational audienc
Monkey and dung beetle activities influence soil seed bank structure
We investigated the influence of Neotropical dung beetles on soil seed bank structure after primary dispersal by the red howler monkey (Alouatta seniculus). We collected seeds from soil samples (up to 15 cm depth) in defecation versus control areas and showed that seed number and diversity increased with monkey frequentation. Seed numbers decreased with depth. Seed viability, ascertained from seed coat integrity, decreased with depth and was higher in sites rarely visited by monkeys compared to control areas or sites frequently visited by monkeys. In field experiments, we incorporated plastic beads (1.3 – 5.8 mm) to fresh dung and monitored bead fate: the proportion of beads found in the soil top 10 cm increased with bead size and this effect was more pronounced in sites more frequently visited by monkeys. The same conclusions were drawn by comparing the beads found in the topsoil and the beads found deeper. We explored bead processing behaviour in several tunneller and roller species by performing experiments involving one species at a time. We showed that selectivity was highly variable: bead exclusion from dung reserves was higher in small than in large beetle species, higher for large than for small beads. Differences in selectivity between medium an