Philippe Razafinjatovo

Bio: Philippe Razafinjatovo is an academic researcher. The author has contributed to research in topics: Biodiversity & Endemism. The author has an hindex of 1, co-authored 1 publications receiving 135 citations.

Climate change adaptation for conservation in Madagascar

Abstract: Madagascar's imperilled biota are now experiencing the effects of a new threat—climate change ([Raxworthy et al . 2008][1]). With more than 90% endemism among plants, mammals, reptiles and amphibians, the stakes are high. The pristine landscapes that allowed this exceptional biodiversity to

Extreme vulnerability of smallholder farmers to agricultural risks and climate change in Madagascar

Abstract: Across the tropics, smallholder farmers already face numerous risks to agricultural production. Climate change is expected to disproportionately affect smallholder farmers and make their livelihoods even more precarious; however, there is limited information on their overall vulnerability and adaptation needs. We conducted surveys of 600 households in Madagascar to characterize the vulnerability of smallholder farmers, identify how farmers cope with risks and explore what strategies are needed to help them adapt to climate change. Malagasy farmers are particularly vulnerable to any shocks to their agricultural system owing to their high dependence on agriculture for their livelihoods, chronic food insecurity, physical isolation and lack of access to formal safety nets. Farmers are frequently exposed to pest and disease outbreaks and extreme weather events (particularly cyclones), which cause significant crop and income losses and exacerbate food insecurity. Although farmers use a variety of risk-coping strategies, these are insufficient to prevent them from remaining food insecure. Few farmers have adjusted their farming strategies in response to climate change, owing to limited resources and capacity. Urgent technical, financial and institutional support is needed to improve the agricultural production and food security of Malagasy farmers and make their livelihoods resilient to climate change.

Museum national d'histoire naturelle

Abstract: Plasma protein electrophoresis is now commonly recognized to be a very reliable diagnostic tool in avian medicine. However, the influence of circannual phenomena such as molt on protein electrophoregrams is poorly documented. Yet, the molt is a period of heavy hormonal and metabolic change in birds. The purpose of this study was to investigate the effects of molt on total protein concentration and electrophoresis patterns in birds. Nineteen bar headed geese (Anser indicus) were blood sampled from mid May to mid August, at 15 day intervals. At the same time, the birds’ molting stage was checked. Total protein concentrations were measured and plasma agarose gel electrophoresis were performed on these samples. The geese were chosen as a model, because these birds molt over a very short period. The total protein concentration, albumin, alpha-2, beta and gamma fractions were at their minimum values during molt, whereas the prealbumin and alpha-1 fractions rose to their maximum levels. This study provides baseline information relevant to changes occurring in avian proteinograms throughout the molt. The increase in the prealbumin and alpha-1 fractions may be related to an increase in plasma thyroid hormones during molt. The decrease observed in albumin, alpha-2, beta and gamma fractions may be related to a protein and energy shift, directed towards feather growth, as well as to an expansion of the circulatory system located around the feather follicles. From a clinical point of view, the observed changes associated with molting were less significant than initially expected, and are not likely to be strong enough to mislead the practitioner.

Adaptive phenotypic plasticity and resilience of vertebrates to increasing climatic unpredictability.

Abstract: As ecosystems undergo global changes, there is increasing interest in understandinghow organisms respond to changing environments. Recent evidence drawn from available vertebratestudies suggests that most of the phenotypic responses to climate change would be due to plasticity.We hypothesize that organisms that have evolved in unpredictable environments inform us about themechanisms of phenotypic plasticity which provide an adaptive response to climate instability. As cli-mate changes increase climatic hazards, these resilience mechanisms are expected to spread withinspecies, populations and communities. We review studies that have demonstrated the importance ofphenotypic plasticity in different life-history traits in overcoming climate uncertainty. We focus onorganisms from unstable, recurrently energetically restrictive environments which possess a varietyof morphological, physiological and/or behavioural adaptations to climate-driven selective pressures.First, we treat plastic morphological changes in response to fluctuating food availability. Adjustmentof morphometric traits and/or organ size to energy supply would be essential in harsh environments.Second, we review the role of flexible energy-saving mechanisms, such as daily torpor, hibernationand energy storage, in overcoming climate-driven energetic shortages. Lastly, we address the role ofplastic modulation of reproduction in fine-tuning the energy allocation to offspring productionaccording to environmental conditions, with an emphasis on opportunistic breeding. Overall, we pre-dict that species (or genotypes) possessing these efficient physiological mechanisms of resilience tounpredictable water and food fluctuations will be selectively advantaged in the face of increasingclimatic instability.KEY WORDS: Physiological flexibility · Global change · Environmental variability · Extreme climaticevents · Morphology · Energy saving · Reproduction