The Science of Nature

, 102:55 | Cite as

Effects of insularity on digestion: living on islands induces shifts in physiological and morphological traits in island reptiles

  • Kostas Sagonas
  • Panayiotis Pafilis
  • Efstratios D. Valakos
Original Paper


Living on islands entails numerous challenges for animals, among which resource scarcity stands out. In order to survive, animals have to optimize energy acquisition. We examined the impact of insularity on digestion comparing a series of physiological and morphological traits of adult males between insular and mainland populations of the Balkan green lizard. Island lizards had longer gastrointestinal tracts and gut passage times and higher digestive efficiencies. The dissection of the hindgut revealed an unexpected finding, the presence of cecal valves that were more frequent in island lizards. Thanks to all above islanders retain food for longer periods and thus maximize energy income and increase the amount of the extracted nutrients. That way, they secure energy income from the limited, in time and quantity, food resources of the islands.


Island life Cecal valves Digestive efficiency Herbivory Lizards 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Kostas Sagonas
    • 1
  • Panayiotis Pafilis
    • 2
  • Efstratios D. Valakos
    • 1
  1. 1.Department of Human and Animal Physiology, Faculty of BiologyUniversity of AthensAthensGreece
  2. 2.Department of Zoology and Marine Biology, Faculty of BiologyUniversity of AthensAthensGreece

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