The Experts below are selected from a list of 675 Experts worldwide ranked by ideXlab platform

Anne-mari Mustonen - One of the best experts on this subject based on the ideXlab platform.

  • maintenance of skeletal muscle energy homeostasis during prolonged wintertime fasting in the raccoon dog Nyctereutes Procyonoides
    Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2015
    Co-Authors: Sanni Kinnunen, Anne-mari Mustonen, Petteri Nieminen, Satu Manttari, Karlheinz Herzig, Samppa Saarela
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is a canid species with autumnal fattening and prolonged wintertime fasting. Nonpathological body weight cycling and the ability to tolerate food deficiency make this species a unique subject for studying physiological mechanisms in energy metabolism. AMP-activated protein kinase (AMPK) is a cellular energy sensor regulating energy homeostasis. During acute fasting, AMPK promotes fatty acid oxidation and enhances glucose uptake. We evaluated the effects of prolonged fasting on muscle energy metabolism in farm-bred raccoon dogs. Total and phosphorylated AMPK and acetyl-CoA carboxylase (ACC), glucose transporter 4 (GLUT 4), insulin receptor and protein kinase B (Akt) protein expressions of hind limb muscles were determined by Western blot after 10 weeks of fasting. Plasma insulin, leptin, ghrelin, glucose and free fatty acid levels were measured, and muscle myosin heavy chain (MHC) isoform composition analyzed. Fasting had no effects on AMPK phosphorylation, but total AMPK expression decreased in m. rectus femoris, m. tibialis anterior and m. extensor digitorum longus resulting in a higher phosphorylation ratio. Decreased total expression was also observed for ACC. Fasting did not influence GLUT 4, insulin receptor or Akt expression, but Akt phosphorylation was lower in m. flexor digitorum superficialis and m. extensor digitorum longus. Three MHC isoforms (I, IIa and IIx) were detected without differences in composition between the fasted and control animals. The studied muscles were resistant to prolonged fasting indicating that raccoon dogs have an effective molecular regulatory system for preserving skeletal muscle function during wintertime immobility and fasting.

  • application of change point analysis to determine winter sleep patterns of the raccoon dog Nyctereutes Procyonoides from body temperature recordings and a multi faceted dietary and behavioral study of wintering
    BMC Ecology, 2012
    Co-Authors: Anne-mari Mustonen, Juha Asikainen, Terttu Lempiainen, Mikko Aspelund, Paavo Hellstedt, Katri Ikonen, Juhani Itamies, Ville Vaha, Jaakko Erkinaro, Mervi Kunnasranta
    Abstract:

    Background A multi-faceted approach was used to investigate the wintertime ecophysiology and behavioral patterns of the raccoon dog, Nyctereutes Procyonoides, a suitable model for winter sleep studies. By utilizing GPS tracking, activity sensors, body temperature (Tb) recordings, change-point analysis (CPA), home range, habitat and dietary analyses, as well as fatty acid signatures (FAS), the impact of the species on wintertime food webs was assessed. The timing of passive bouts was determined with multiple methods and compared to Tb data analyzed by CPA.

  • selective seasonal fatty acid accumulation and mobilization in the wild raccoon dog Nyctereutes Procyonoides
    Lipids, 2007
    Co-Authors: Anne-mari Mustonen, Juha Asikainen, Petteri Nieminen
    Abstract:

    Previous studies on laboratory rodents, rabbits and humans have demonstrated that fatty acid (FA) mobilization from white adipose tissue (WAT) is selective and its efficiency is related to FA structure. Selective FA mobilization was also documented in a carnivore, the farmed raccoon dog (Nyctereutes Procyonoides), fasted for 8 weeks. The present study explored whether similar selectivity of FA mobilization was manifested in wild mammals experiencing seasonal food scarcity and abundance. Fractional mobilization from and incorporation into WAT of a wide spectrum of FA were studied by gas–liquid chromatography from the subcutaneous WAT of free-ranging raccoon dogs with the same individuals sampled in consecutive seasons. The wintertime FA mobilization was selective and mostly confirmed the patterns of FA release in captivity. Mobilization correlated inversely with the FA chain length but increased with unsaturation and when the first double bond was located closer to the methyl end. 18–20C n-3 polyunsaturated FA (PUFA) and 14–17C monounsaturated FA (MUFA) were preferentially mobilized while 19–24C saturated FA and MUFA were preserved during wintering. The summertime FA incorporation correlated inversely with the chain length and increased with unsaturation and in MUFA and PUFA with double bonds closer to the methyl end. The principles of selective FA mobilization were valid in wild mammals. FA incorporation was also selective and reversed the wintertime losses of the preferably mobilized FA.

  • seasonal rhythms of body temperature in the free ranging raccoon dog Nyctereutes Procyonoides with special emphasis on winter sleep
    Chronobiology International, 2007
    Co-Authors: Anne-mari Mustonen, Juha Asikainen, Tommi Paakkonen, Kaarina Kauhala, Petteri Nieminen
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is the only canid with passive overwintering in areas with cold winters, but the depth and rhythmicity of wintertime hypothermia in the wild raccoon dog are unknown. To study the seasonal rhythms of body temperature (Tb), seven free‐ranging animals were captured and implanted with intra‐abdominal Tb loggers and radio‐tracked during years 2004–2006. The average size of the home ranges was 306±26 ha, and the average 24 h Tb was 38.0±<0.01°C during the snow‐free period (May–November). The highest and lowest Tb were usually recorded around midnight (21∶00–02∶00 h) and between 05∶00–11∶00 h, respectively, and the range of the 24 h oscillations was 1.2±0.01°C. The animals lost approximately 43±6% of body mass in winter (December–April), when the average size of the home ranges was 372±108 ha. During the 2–9‐wk periods of passivity in January–March, the average 24 h Tb decreased by 1.4–2.1°C compared to the snow‐free period. The raccoon dogs were hypothermic for 5 h in ...

  • thermoregulatory adaptations of the overwintering captive raccoon dog Nyctereutes Procyonoides in boreal climate
    Journal of Experimental Zoology Part A: Comparative Experimental Biology, 2005
    Co-Authors: Petteri Nieminen, Juha Asikainen, Tommi Paakkonen, Martina Cittovakontu, Esa Hohtola, Jaakko Mononen, Teija Pyykonen, Anne-mari Mustonen
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is a nocturnal canid thought to utilise passive wintering strategy in the boreal climate. To record the deep body temperature (Tb), 12 farmed raccoon dogs were implanted with intra-abdominal Tb loggers on November 26, 2003. Between December 3, 2003 and January 27, 2004 half of the animals were fasted for 8 weeks. The amplitude of the diurnal Tb oscillations increased due to fasting. However, the mean diurnal Tb was lower in the fasted animals only during two occasions. Unlike observed previously in other species, not only did the raccoon dogs experience hypothermia between 0600 and 1000 hr but also hyperthermia between noon and 1800 hr. The fasted animals were as active as the fed animals measured after 42–43 days of fasting and there was a significant cross-correlation between physical activity and Tb. The nocturnal period of hypothermia is probably an adaptation to save energy during food deprivation. The diurnal hyperthermia could be explained by the opportunistic foraging behaviour of the species. Opposite to the established assumptions, the raccoon dog does not seem to enter winter sleep on fur farms. In the future it is important to determine if true winter sleep occurs in nature in the species. J. Exp. Zool. 303A:776–784, 2005. © 2005 Wiley-Liss, Inc.

Petteri Nieminen - One of the best experts on this subject based on the ideXlab platform.

  • maintenance of skeletal muscle energy homeostasis during prolonged wintertime fasting in the raccoon dog Nyctereutes Procyonoides
    Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2015
    Co-Authors: Sanni Kinnunen, Anne-mari Mustonen, Petteri Nieminen, Satu Manttari, Karlheinz Herzig, Samppa Saarela
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is a canid species with autumnal fattening and prolonged wintertime fasting. Nonpathological body weight cycling and the ability to tolerate food deficiency make this species a unique subject for studying physiological mechanisms in energy metabolism. AMP-activated protein kinase (AMPK) is a cellular energy sensor regulating energy homeostasis. During acute fasting, AMPK promotes fatty acid oxidation and enhances glucose uptake. We evaluated the effects of prolonged fasting on muscle energy metabolism in farm-bred raccoon dogs. Total and phosphorylated AMPK and acetyl-CoA carboxylase (ACC), glucose transporter 4 (GLUT 4), insulin receptor and protein kinase B (Akt) protein expressions of hind limb muscles were determined by Western blot after 10 weeks of fasting. Plasma insulin, leptin, ghrelin, glucose and free fatty acid levels were measured, and muscle myosin heavy chain (MHC) isoform composition analyzed. Fasting had no effects on AMPK phosphorylation, but total AMPK expression decreased in m. rectus femoris, m. tibialis anterior and m. extensor digitorum longus resulting in a higher phosphorylation ratio. Decreased total expression was also observed for ACC. Fasting did not influence GLUT 4, insulin receptor or Akt expression, but Akt phosphorylation was lower in m. flexor digitorum superficialis and m. extensor digitorum longus. Three MHC isoforms (I, IIa and IIx) were detected without differences in composition between the fasted and control animals. The studied muscles were resistant to prolonged fasting indicating that raccoon dogs have an effective molecular regulatory system for preserving skeletal muscle function during wintertime immobility and fasting.

  • selective seasonal fatty acid accumulation and mobilization in the wild raccoon dog Nyctereutes Procyonoides
    Lipids, 2007
    Co-Authors: Anne-mari Mustonen, Juha Asikainen, Petteri Nieminen
    Abstract:

    Previous studies on laboratory rodents, rabbits and humans have demonstrated that fatty acid (FA) mobilization from white adipose tissue (WAT) is selective and its efficiency is related to FA structure. Selective FA mobilization was also documented in a carnivore, the farmed raccoon dog (Nyctereutes Procyonoides), fasted for 8 weeks. The present study explored whether similar selectivity of FA mobilization was manifested in wild mammals experiencing seasonal food scarcity and abundance. Fractional mobilization from and incorporation into WAT of a wide spectrum of FA were studied by gas–liquid chromatography from the subcutaneous WAT of free-ranging raccoon dogs with the same individuals sampled in consecutive seasons. The wintertime FA mobilization was selective and mostly confirmed the patterns of FA release in captivity. Mobilization correlated inversely with the FA chain length but increased with unsaturation and when the first double bond was located closer to the methyl end. 18–20C n-3 polyunsaturated FA (PUFA) and 14–17C monounsaturated FA (MUFA) were preferentially mobilized while 19–24C saturated FA and MUFA were preserved during wintering. The summertime FA incorporation correlated inversely with the chain length and increased with unsaturation and in MUFA and PUFA with double bonds closer to the methyl end. The principles of selective FA mobilization were valid in wild mammals. FA incorporation was also selective and reversed the wintertime losses of the preferably mobilized FA.

  • seasonal rhythms of body temperature in the free ranging raccoon dog Nyctereutes Procyonoides with special emphasis on winter sleep
    Chronobiology International, 2007
    Co-Authors: Anne-mari Mustonen, Juha Asikainen, Tommi Paakkonen, Kaarina Kauhala, Petteri Nieminen
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is the only canid with passive overwintering in areas with cold winters, but the depth and rhythmicity of wintertime hypothermia in the wild raccoon dog are unknown. To study the seasonal rhythms of body temperature (Tb), seven free‐ranging animals were captured and implanted with intra‐abdominal Tb loggers and radio‐tracked during years 2004–2006. The average size of the home ranges was 306±26 ha, and the average 24 h Tb was 38.0±<0.01°C during the snow‐free period (May–November). The highest and lowest Tb were usually recorded around midnight (21∶00–02∶00 h) and between 05∶00–11∶00 h, respectively, and the range of the 24 h oscillations was 1.2±0.01°C. The animals lost approximately 43±6% of body mass in winter (December–April), when the average size of the home ranges was 372±108 ha. During the 2–9‐wk periods of passivity in January–March, the average 24 h Tb decreased by 1.4–2.1°C compared to the snow‐free period. The raccoon dogs were hypothermic for 5 h in ...

  • thermoregulatory adaptations of the overwintering captive raccoon dog Nyctereutes Procyonoides in boreal climate
    Journal of Experimental Zoology Part A: Comparative Experimental Biology, 2005
    Co-Authors: Petteri Nieminen, Juha Asikainen, Tommi Paakkonen, Martina Cittovakontu, Esa Hohtola, Jaakko Mononen, Teija Pyykonen, Anne-mari Mustonen
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is a nocturnal canid thought to utilise passive wintering strategy in the boreal climate. To record the deep body temperature (Tb), 12 farmed raccoon dogs were implanted with intra-abdominal Tb loggers on November 26, 2003. Between December 3, 2003 and January 27, 2004 half of the animals were fasted for 8 weeks. The amplitude of the diurnal Tb oscillations increased due to fasting. However, the mean diurnal Tb was lower in the fasted animals only during two occasions. Unlike observed previously in other species, not only did the raccoon dogs experience hypothermia between 0600 and 1000 hr but also hyperthermia between noon and 1800 hr. The fasted animals were as active as the fed animals measured after 42–43 days of fasting and there was a significant cross-correlation between physical activity and Tb. The nocturnal period of hypothermia is probably an adaptation to save energy during food deprivation. The diurnal hyperthermia could be explained by the opportunistic foraging behaviour of the species. Opposite to the established assumptions, the raccoon dog does not seem to enter winter sleep on fur farms. In the future it is important to determine if true winter sleep occurs in nature in the species. J. Exp. Zool. 303A:776–784, 2005. © 2005 Wiley-Liss, Inc.

  • thermoregulatory adaptations of the overwintering captive raccoon dog Nyctereutes Procyonoides in boreal climate
    Journal of Experimental Zoology Part A: Comparative Experimental Biology, 2005
    Co-Authors: Petteri Nieminen, Juha Asikainen, Tommi Paakkonen, Martina Cittovakontu, Esa Hohtola, Jaakko Mononen, Teija Pyykonen, Anne-mari Mustonen
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is a nocturnal canid thought to utilise passive wintering strategy in the boreal climate. To record the deep body temperature (Tb), 12 farmed raccoon dogs were implanted with intra-abdominal Tb loggers on November 26, 2003. Between December 3, 2003 and January 27, 2004 half of the animals were fasted for 8 weeks. The amplitude of the diurnal Tb oscillations increased due to fasting. However, the mean diurnal Tb was lower in the fasted animals only during two occasions. Unlike observed previously in other species, not only did the raccoon dogs experience hypothermia between 0600 and 1000 hr but also hyperthermia between noon and 1800 hr. The fasted animals were as active as the fed animals measured after 42–43 days of fasting and there was a significant cross-correlation between physical activity and Tb. The nocturnal period of hypothermia is probably an adaptation to save energy during food deprivation. The diurnal hyperthermia could be explained by the opportunistic foraging behaviour of the species. Opposite to the established assumptions, the raccoon dog does not seem to enter winter sleep on fur farms. In the future it is important to determine if true winter sleep occurs in nature in the species. J. Exp. Zool. 303A:776–784, 2005. © 2005 Wiley-Liss, Inc.

Sven Klimpel - One of the best experts on this subject based on the ideXlab platform.

  • climatic niche comparison of raccoons procyon lotor and raccoon dogs Nyctereutes Procyonoides in their native and non native ranges
    Mammal Review, 2021
    Co-Authors: Judith Kochmann, Sarah Cunze, Sven Klimpel
    Abstract:

    During the last century, the practice of fur farming in Europe led to the introduction of two mammal species from opposite ends of the world With their subsequent unintentional escape from captivity or intentional releases, the process of slow expansion and establishment in Europe began The raccoon Procyon lotor and the raccoon dog Nyctereutes Procyonoides are included on the European Union’s list of invasive alien species We characterised the current climatic niches of the two species in their native ranges in North America and Asia, and compared them with their non-native-range niches in Europe, where we also projected climatic suitability The aim was to locate suitable habitats beyond their current ranges and assess where a range expansion can be expected Niche comparison and the projection of climatic suitability in Europe were based on eight bioclimatic variables and presence records from the Global Biodiversity Information Facility database For niche modelling, we applied the maximum entropy approach (Maxent) and used the native-range data for training Minimum temperature of the coldest month (bio06) was identified as the most important bioclimatic variable in the habitat suitability models for both species Different tolerance levels regarding this variable might explain small differences between the species’ projected ranges, especially in the north and east of Europe The high niche unfilling for both species in Europe suggests a potential for expansion beyond their present ranges With only little understanding of their ecological impacts in their new ranges, including the potential risk of Nyctereutes Procyonoides as SARS-CoV-2 reservoir hosts, further research and management is required at various spatial scales in Europe © 2021 The Authors Mammal Review published by Mammal Society and John Wiley & Sons Ltd

  • de novo genome assembly of the raccoon dog Nyctereutes Procyonoides
    Frontiers in Genetics, 2021
    Co-Authors: Luis J Chueca, Judith Kochmann, Tilman Schell, Carola Greve, Axel Janke, Markus Pfenninger, Sven Klimpel
    Abstract:

    The raccoon dog, Nyctereutes Procyonoides (NCBI Taxonomy ID: 34880, Figure 1a) belongs to the family Canidae, with foxes (genus Vulpes) being their closest relatives (Lindblad-Toh et al., 2005; Sun et al., 2019). Its original distribution in East Asia ranges from south-eastern Siberia to northern Vietnam and the Japanese islands. In the early 20th century, the raccoon dog was introduced into Western Russia for fur breeding and hunting purposes, which led to its widespread establishment in many European countries, Figure 1b. Together with the raccoon (Procyon lotor), it is now listed in Europe as an invasive species of Union concern (Regulation (EU) No. 1143/2014) and member states are required to control pathways of introductions and manage established populations. Open in a separate window Figure 1 (a) Picture of an adult specimen of raccoon dog (Nyctereutes Procyonoides), copyright © Dorian D. Dorge. (b) Native (orange) and introduced (purple) distributions ranges of raccoon dog (source IUCN red list). (c) Workflow of genome assembly and annotation followed in this study. (d) Blob plot showing read depth of coverage, GC content and size of each scaffold. Size of the blobs correspond to size of the scaffold and color corresponds to taxonomic assignment of BLAST (blue = Carnivora). (e) Whole genome synteny, obtained with Jupiterplot, between the Canis lupus familiaris chromosome-level assembly (on the left) and the raccoon dog genome assembly obtained in this study (on the right). The lines indicate aligned regions between the two assemblies.

Marek Switonski - One of the best experts on this subject based on the ideXlab platform.

Juha Asikainen - One of the best experts on this subject based on the ideXlab platform.

  • application of change point analysis to determine winter sleep patterns of the raccoon dog Nyctereutes Procyonoides from body temperature recordings and a multi faceted dietary and behavioral study of wintering
    BMC Ecology, 2012
    Co-Authors: Anne-mari Mustonen, Juha Asikainen, Terttu Lempiainen, Mikko Aspelund, Paavo Hellstedt, Katri Ikonen, Juhani Itamies, Ville Vaha, Jaakko Erkinaro, Mervi Kunnasranta
    Abstract:

    Background A multi-faceted approach was used to investigate the wintertime ecophysiology and behavioral patterns of the raccoon dog, Nyctereutes Procyonoides, a suitable model for winter sleep studies. By utilizing GPS tracking, activity sensors, body temperature (Tb) recordings, change-point analysis (CPA), home range, habitat and dietary analyses, as well as fatty acid signatures (FAS), the impact of the species on wintertime food webs was assessed. The timing of passive bouts was determined with multiple methods and compared to Tb data analyzed by CPA.

  • selective seasonal fatty acid accumulation and mobilization in the wild raccoon dog Nyctereutes Procyonoides
    Lipids, 2007
    Co-Authors: Anne-mari Mustonen, Juha Asikainen, Petteri Nieminen
    Abstract:

    Previous studies on laboratory rodents, rabbits and humans have demonstrated that fatty acid (FA) mobilization from white adipose tissue (WAT) is selective and its efficiency is related to FA structure. Selective FA mobilization was also documented in a carnivore, the farmed raccoon dog (Nyctereutes Procyonoides), fasted for 8 weeks. The present study explored whether similar selectivity of FA mobilization was manifested in wild mammals experiencing seasonal food scarcity and abundance. Fractional mobilization from and incorporation into WAT of a wide spectrum of FA were studied by gas–liquid chromatography from the subcutaneous WAT of free-ranging raccoon dogs with the same individuals sampled in consecutive seasons. The wintertime FA mobilization was selective and mostly confirmed the patterns of FA release in captivity. Mobilization correlated inversely with the FA chain length but increased with unsaturation and when the first double bond was located closer to the methyl end. 18–20C n-3 polyunsaturated FA (PUFA) and 14–17C monounsaturated FA (MUFA) were preferentially mobilized while 19–24C saturated FA and MUFA were preserved during wintering. The summertime FA incorporation correlated inversely with the chain length and increased with unsaturation and in MUFA and PUFA with double bonds closer to the methyl end. The principles of selective FA mobilization were valid in wild mammals. FA incorporation was also selective and reversed the wintertime losses of the preferably mobilized FA.

  • seasonal rhythms of body temperature in the free ranging raccoon dog Nyctereutes Procyonoides with special emphasis on winter sleep
    Chronobiology International, 2007
    Co-Authors: Anne-mari Mustonen, Juha Asikainen, Tommi Paakkonen, Kaarina Kauhala, Petteri Nieminen
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is the only canid with passive overwintering in areas with cold winters, but the depth and rhythmicity of wintertime hypothermia in the wild raccoon dog are unknown. To study the seasonal rhythms of body temperature (Tb), seven free‐ranging animals were captured and implanted with intra‐abdominal Tb loggers and radio‐tracked during years 2004–2006. The average size of the home ranges was 306±26 ha, and the average 24 h Tb was 38.0±<0.01°C during the snow‐free period (May–November). The highest and lowest Tb were usually recorded around midnight (21∶00–02∶00 h) and between 05∶00–11∶00 h, respectively, and the range of the 24 h oscillations was 1.2±0.01°C. The animals lost approximately 43±6% of body mass in winter (December–April), when the average size of the home ranges was 372±108 ha. During the 2–9‐wk periods of passivity in January–March, the average 24 h Tb decreased by 1.4–2.1°C compared to the snow‐free period. The raccoon dogs were hypothermic for 5 h in ...

  • thermoregulatory adaptations of the overwintering captive raccoon dog Nyctereutes Procyonoides in boreal climate
    Journal of Experimental Zoology Part A: Comparative Experimental Biology, 2005
    Co-Authors: Petteri Nieminen, Juha Asikainen, Tommi Paakkonen, Martina Cittovakontu, Esa Hohtola, Jaakko Mononen, Teija Pyykonen, Anne-mari Mustonen
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is a nocturnal canid thought to utilise passive wintering strategy in the boreal climate. To record the deep body temperature (Tb), 12 farmed raccoon dogs were implanted with intra-abdominal Tb loggers on November 26, 2003. Between December 3, 2003 and January 27, 2004 half of the animals were fasted for 8 weeks. The amplitude of the diurnal Tb oscillations increased due to fasting. However, the mean diurnal Tb was lower in the fasted animals only during two occasions. Unlike observed previously in other species, not only did the raccoon dogs experience hypothermia between 0600 and 1000 hr but also hyperthermia between noon and 1800 hr. The fasted animals were as active as the fed animals measured after 42–43 days of fasting and there was a significant cross-correlation between physical activity and Tb. The nocturnal period of hypothermia is probably an adaptation to save energy during food deprivation. The diurnal hyperthermia could be explained by the opportunistic foraging behaviour of the species. Opposite to the established assumptions, the raccoon dog does not seem to enter winter sleep on fur farms. In the future it is important to determine if true winter sleep occurs in nature in the species. J. Exp. Zool. 303A:776–784, 2005. © 2005 Wiley-Liss, Inc.

  • thermoregulatory adaptations of the overwintering captive raccoon dog Nyctereutes Procyonoides in boreal climate
    Journal of Experimental Zoology Part A: Comparative Experimental Biology, 2005
    Co-Authors: Petteri Nieminen, Juha Asikainen, Tommi Paakkonen, Martina Cittovakontu, Esa Hohtola, Jaakko Mononen, Teija Pyykonen, Anne-mari Mustonen
    Abstract:

    The raccoon dog (Nyctereutes Procyonoides) is a nocturnal canid thought to utilise passive wintering strategy in the boreal climate. To record the deep body temperature (Tb), 12 farmed raccoon dogs were implanted with intra-abdominal Tb loggers on November 26, 2003. Between December 3, 2003 and January 27, 2004 half of the animals were fasted for 8 weeks. The amplitude of the diurnal Tb oscillations increased due to fasting. However, the mean diurnal Tb was lower in the fasted animals only during two occasions. Unlike observed previously in other species, not only did the raccoon dogs experience hypothermia between 0600 and 1000 hr but also hyperthermia between noon and 1800 hr. The fasted animals were as active as the fed animals measured after 42–43 days of fasting and there was a significant cross-correlation between physical activity and Tb. The nocturnal period of hypothermia is probably an adaptation to save energy during food deprivation. The diurnal hyperthermia could be explained by the opportunistic foraging behaviour of the species. Opposite to the established assumptions, the raccoon dog does not seem to enter winter sleep on fur farms. In the future it is important to determine if true winter sleep occurs in nature in the species. J. Exp. Zool. 303A:776–784, 2005. © 2005 Wiley-Liss, Inc.