Global warming and Bergmann’s rule: do central European passerines adjust their body size to rising temperatures?

Recent climate change has caused diverse ecological responses in plants and animals. However, relatively little is known about homeothermic animals’ ability to adapt to changing temperature regimes through changes in body size, in accordance with Bergmann’s rule. We used fluctuations in mean annual temperatures in south-west Germany since 1972 in order to look for direct links between temperature and two aspects of body size: body mass and flight feather length. Data from regionally born juveniles of 12 passerine bird species were analysed. Body mass and feather length varied significantly among years in eight and nine species, respectively. Typically the inter-annual changes in morphology were complexly non-linear, as was inter-annual variation in temperature. For six (body mass) and seven species (feather length), these inter-annual fluctuations were significantly correlated with temperature fluctuations. However, negative correlations consistent with Bergmann’s rule were only found for five species, either for body mass or feather length. In several of the species for which body mass and feather length was significantly associated with temperature, morphological responses were better predicted by temperature data that were smoothed across multiple years than by the actual mean breeding season temperatures of the year of birth. This was found in five species for body mass and three species for feather length. These results suggest that changes in body size may not merely be the result of phenotypic plasticity but may hint at genetically based microevolutionary adaptations

Offene Offsetkorrektur bei symptomatischem Cam-Impingement. Therapie über einen minimalinvasiven anterolateralen Zugang

BACKGROUND Surgical treatment of femoroacetabular impingement (FAI) is nowadays achieved by either open surgical hip dislocation or hip arthroscopy. However, drawbacks of both procedures include the invasiveness of the open procedure and a high learning curve to successfully perform arthroscopic treatment. In our institution, we established a minimally invasive, arthroscopically assisted, antero-lateral approach for the correction of cam type FAI. OBJECTIVES The goal of the study was to describe the surgical technique and highlight the short-term clinical outcome in a consecutive series of patients operated between 2011 and 2014 in our institution. MATERIALS AND METHODS In total, 77 patients were included in this study. The patients were allocated to two groups (Toennis = 0: Group I; Toennis 1 and 2: Group II). Clinical and radiographic follow up was obtained at 6 and 12 weeks postoperatively. Clinical outcome was assessed using the Hip-Outcome-Score. RESULTS The mean age of patients in Group I was 25 (16-48) years and in Group II 38 (17-50) years respectively. Internal rotation (IR) in 90° flexion increased by 11 degrees from pre- to postoperatively in Group I (p < 0.001) and by 14° in Group II (p < 0.001). The Hip Outcome Score revealed the ability to perform sports with reduced pain at three months follow up. Subjectively, all patients benefitted in terms of pain and hip function in both groups (p < 0.001). There were no complications with long-term morbidity during the perioperative course. CONCLUSION Arthroscopically assisted cam resection using a minimally invasive anterolateral approach is a safe technique for the treatment of FAI. At short term follow up, nearly all operated patients seem to benefit in terms of pain and hip function. The influence of progression of osteoarthritis still has to be shown