Ultraviolet signals ultra-aggression in a lizard

Understanding the role of multiple colour signals during sexual signalling is a central theme in animal communication. We quantified the role of multiple colour signals (including ultraviolet, UV), measures of body size and testosterone levels in settling disputes between male rivals in an elaborately ornamented, African lizard, played out in a large 'tournament' in the wild. The hue and brightness (total reflectance) of the UV throat in Augrabies flat lizards, Platysaurus broadleyi, as well as body size, were consistent and strong predictors of 'fighting ability'. Males with high fighting ability were larger and displayed a UV throat with low total reflectance. In contrast, males with low fighting ability were smaller and had violet throats with broader spectral reflectance curves (higher total reflectance). As fighting ability is associated with alternative reproductive tactics in this system (territorial versus floater), we also examined the role of colour signals in predicting male reproductive tactic. Territorial males had UV throats with higher chroma but had poorer body condition than floater males, probably because of the energetic costs of maintaining a territory. Although testosterone was not a significant predictor of fighting ability or reproductive tactic, it was correlated with the hue of the UV throat, suggesting that testosterone may impose some constraint on signal expression. Lastly, we show that within the context of the natural signalling environment, UV-reflective throats constitute a conspicuous, effective signal that male Augrabies flat lizards use to advertise their status honestly to rivals. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

What needs to be done? Occupational therapy responsibilities and challenges regarding human rights

Background: Addressing human rights issues brings forth ethical and political responsibilities for occupational therapists and requires new epistemological and educational approaches. The way occupational therapists have faced these challenges has depended upon historical, cultural and social contexts. Aim and method: By means of literature review and historical analysis, this paper reflects on how occupational therapists have dealt with human matters issues and on the contemporary changes within the profession. Results and discussion: The paper portrays how Latin American occupational therapists have engaged in social transformation by choosing not to transform ethical and political problems into technical matters. Taking into account experiences and views from South Africa, Brazil and Chile, the paper outlines the importance of developing political literacy and interdisciplinary professional/postprofessional education to prepare the new generation of occupational therapists to engage in social transformation. Addressing issues of invisibility and lack of access to human rights, the paper reflects on the need of developing conceptual tools and strategies for change, and discusses the transformations being produced in contemporary occupational therapy. Conclusion: Occupational therapists and scientists need to be attentive to human rights issues. They also need to answer the call for interconnectedness in the present-day complex societies, and engage in networking and a cross-bordering dialogue. Nevertheless, although necessary and welcome, international cooperation requires a permanent exercise of cultural sensitivity, political awareness and self-awareness.