Estrus and estrogen changes in mated and unmated free-living European ground squirrels

Eva Millesi, Susanne Huber, Katharina Pieta, Manfred Walzl, Walter Arnold, John Dittami

    Publications: Contribution to journalArticlePeer Reviewed

    Abstract

    The course of behavioral and vaginal estrus and patterns of circulating estrogens were followed in free-living European ground squirrels (Spermophilus citellus) after their emergence from hibernation. Normally mating females were compared to a second group in an area where males had been removed from the population before female emergence. Both groups showed vaginal estrus, but the patterns differed. Mating shortened vaginal estrus to a 3-day period compared to 8 days in unmated females. The extent (cell number) of cell cornification during estrus and the cellular components (percentage distribution) of metestrus did not differ between the two groups. Females in the area without males had significantly higher estrogen levels during estrus and metestrus compared to those in the control area. European ground squirrels were found to be monestrous, as none of the unmated females reentered estrus after met- or diestrus was detected. The prolongation of vaginal estrus in unmated females can be viewed as either a physiological inevitability or an adaptation to low mate availability. The extension is still relatively short compared to other sciurid species and perhaps a product of constraints producing a strict time frame for reproduction. (C) 2000 Academic Press.
    Original languageEnglish
    Pages (from-to)190-197
    Number of pages8
    JournalHormones and Behavior
    Volume37
    Issue number3
    DOIs
    Publication statusPublished - 2000

    Austrian Fields of Science 2012

    • 1060 Biology

    Fingerprint

    Dive into the research topics of 'Estrus and estrogen changes in mated and unmated free-living European ground squirrels'. Together they form a unique fingerprint.

    Cite this