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Winterschlaf inA den Tropen: Ein Kontinuum an Möglichkeiten Kathrin H. Dausmann Energy Seasonal fluctuations low temperatures limited food availability no open water “Traditional“ daily torpor and hibernation Heldmaier et al. Resp Physiol Neurobio 2004 controlled reduction of metabolic rate & body temperature high energy savings (> 90%) “Traditional“ daily torpor and hibernation Hut et al. JCP B 2002 controlled reduction of metabolic rate & body temperature high energy savings (> 90%) Daily and seasonal fluctuations & unpredictability N D J O F M S A rainy season (= summer) Low temperatures Limited food availability No open water A J J M dry season (= winter) 80 Ta max 35 30 70 60 25 50 20 40 15 30 20 pre 10 5 10 Ta min 0 January 0 June precipitation (mm) temperature (°C) 40 100 km Daubentoniidae Lepilemuridae Lemurs Cheirogaleidae Phaner (4 species) Cheirogaleus (6 species) Allocebus (1 species) Mirza (2 species) Microcebus (16 species) Lemuridae Indriidae Dense humid forest Secondary complex Dense dry forest Mangrove Savannah Swamps Cheirogaleus medius – Obligate hibernation Fat-tailed dwarf lemur Cheirogaleus medius 100 km Cheirogaleus medius – Obligate hibernation Cheirogaleus medius – Obligate hibernation north • Nocturnal, arboreal, 130g • Frugivorous, insectivorous • Social monogamy • Defended territories 100 m fat-tailed dwarf lemur Cheirogaleus Fat-tailed dwarfmedius lemur males Cheirogaleus medius females Dausmann, unpublished Cheirogaleus medius – Obligate hibernation Cheirogaleus medius – Obligate hibernation temperature (°C) 40 30 20 10 0 time (days) passive thermoregulation strong daily fluctuations (up to 30°C) Tb male Ttree tree hole Ta outside Cheirogaleus medius – Obligate hibernation Increasing insulation of tree hole Fluctuating, very flexible patterns of Tb and MR Marmota marmota Arnold Ver. Dtsch. Zool. Ges. 1993 Dausmann et al. Nature 2004 JCP B 2005 Cheirogaleus medius – Obligate hibernation Fluctuating, very flexible patterns of Tb and MR Energy savings independent of hibernacula choice Energy savings = 70 % Tb min = 9.3 °C Dausmann et al. JCP B 2009 Cheirogaleus crossleyi and C. sibreei – Underground hibernators 100 km Marina Blanco Cheirogaleus crossleyi and C. sibreei – underground hibernators 400/300 g high altitude habitat (Ta < 0°C) underground hibernation (5 months ) ~ constant Tb with arousals Cheirogaleus crossleyi and C. sibreei – Underground hibernators 400/300 g High altitude habitat (Ta < 0°C) 40 Temperature (°C) 35 30 25 20 15 10 5 0 Energy savings = 86/89 % Tb min = 7.5/10.5 °C Days Underground hibernation (5 months ) ~ Constant Tb with arousals Blanco et al., unpubl. data Cheirogaleus – Obligate hibernation All dwarf lemurs obligate hibernators „Wie man sich bettet, so schläft man.“ Microcebus griseorufus – Physiological flexibility 100 km 50 g Very seasonal, unpredictable habitat (spiny forest) physiological flexibility Susanne Kobbe Microcebus griseorufus – Physiological flexibility Daily torpor temperature (°C) temperature (°C) Occasional torpor days temperature (°C) temperature (°C) days days Prolonged torpor days Kobbe et al. JCP B 2011 Continuous hibernation Microcebus griseorufus – Physiological flexibility Daily torpor temperature (°C) temperature (°C) Occasional torpor days temperature (°C) temperature (°C) days days Prolonged torpor days Kobbe et al. JCP B 2011 Continuous hibernation Microcebus griseorufus – Physiological flexibility 2014 Daily torpor temperature (°C) temperature (°C) Occasional torpor 2014 days Prolonged torpor days temperature (°C) temperature (°C) days 2014 2015 days Kobbe et al. JCP B 2011 Continuous hibernation Microcebus griseorufus – Physiological flexibility Downwards shift of lower critical temperature during normothermia Summer TTlclc Summer Tlc Winter Tlc Transition period 7.5°C Jack - and master - of all trades: the Cheirogaleidae 50 0 100 km 5 months hibernation 7 months hibernation torpor, hibernation Antananarivo Morondava Ranomafana Tulear Fort Dauphin torpor, hibernation 3 months hibernation Kirindy Dense humid forest Secondary complex Dense dry forest Mangrove Savannah Swamps 5 months hibernation 4 months hibernation torpor, hibernation Jack - and master - of all trades: the Cheirogaleidae • Very seasonal climatic differences • Very arid • Very unpredictable Jack - and master - of all trades: the Cheirogaleidae climatic differences strategy depended on body condition Kobbe et al. JCP B 2011 Jack - and master - of all trades: the Cheirogaleidae Climatic differences Strategy depended on body condition Different reproductive patterns 2x per year Reproduction Lifetime Reproduction Lifetime once every 2 years 100 km Galagos Lorises Daubentoniidae Lepilemuridae Lemurs Cheirogaleidae Phaner (4 species) Cheirogaleus (7 species) Allocebus (1 species) Mirza (2 species) Microcebus (16 species) Lemuridae Indriidae Dense humid forest Secondary complex Dense dry forest Mangrove Savannah Swamps Galago moholi – Torpor as emergency strategy Only 25% of individuals Only subadults, mostly males Singular occasions Not routine seasonal adjustment Julia Nowack Nowack et al. PLoS ONE 2010 Afrotropical heterothermy – a continuum of possibilities Rare Use of Heterothermy Obligate Hibernation 2x per year Gestation: 120d 60d once every 2 years 60d 60d Conclusion Primate species do enter torpid states, even in climates considered tropical Extent of heterothermy varies between closely related species, within species, for individuals of one population, or for individuals during different years – reflecting ecological and evolutionary forces Physiological flexibility particularily important for species living in less predictable habitats climate change? Commission Tripartite, Ministère pour la Production Animale, Département des Eaux et Forêts and ANGAP/MNP of the Malagasy gouvernment Université d'Antananarivo (Département de Biologie Animale, Département d'Anthropologie et de Biologie Evolutive, Département de Biologie et Ecologie Végétale: Prof. Dres. Berthe Rakotosamimanana, Daniel Rakotondravony, Olga Ramilijaona, Charlotte Rajeriarison, Edmond Roger) Parc Botanique et Zoologique de Tsimbazaza Centre de Formation Professionnelle Forestière de Morondava Deutsches Primatenzentrum, Prof. Dr. Peter Kappeler, Dr. Rodin Rasoloarison, Léonard Razafimanantsoa Alpha from Marofandilia, Dr. Joanna Fietz, François from Marofandilia, Peggy Giertz, Dr. Julian Glos, Jean-Claude from Beroboka, Dr. Jutta Schmid, Tina Stahl, Christine Wiedemann Prof. Dr. Gerhard Heldmaier Prof. Dr. Jörg Ganzhorn Deutsche Forschungsgemeinschaft BMZ/GTZ Deutscher Akademischer Austauschdienst WWF Germany and WWF Madagascar Thank you for your attention and for not entering torpor during this talk! "It is well known that within the tropics, the hybernation, or more properly aestivation, of animals is determined not by the temperature, but by the times of drought". The Voyage of the Beagle
