A simplified method for monitoring progestagens in African elephants under field conditions

Authors

  • Elizabeth W. Freeman,

    Corresponding author
    1. Center for Species Survival, Conservation & Research Center, National Zoological Park, Front Royal, VA 22630, USA
    2. New Century College, George Mason University, Fairfax, VA 22030, USA
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  • F. Nicole Abbondanza,

    1. Center for Species Survival, Conservation & Research Center, National Zoological Park, Front Royal, VA 22630, USA
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  • Jordana M. Meyer,

    1. Center for Species Survival, Conservation & Research Center, National Zoological Park, Front Royal, VA 22630, USA
    2. Department of Biology, Georgia Southern University, Statesboro, GA 30460, USA
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  • Bruce A. Schulte,

    1. Department of Biology, Georgia Southern University, Statesboro, GA 30460, USA
    2. Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA
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  • Janine L. Brown

    1. Center for Species Survival, Conservation & Research Center, National Zoological Park, Front Royal, VA 22630, USA
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Correspondence author. E-mail: efreeman@gmu.edu

Summary

1. Hormone analyses are frequently used to support management of wildlife; however, current techniques are not very field-friendly. In situ hormone monitoring is often expensive, time consuming and logistically difficult. Thus, a new method for assessing ovarian cycle activity non-invasively in free-ranging African elephants was developed.

2. The technique involves handshaking faecal samples in common organic solvents, use of environmentally stable antibody-coated microtitre plates and assessment of progestagen concentrations based on a visual colour change.

3. Studies using ex situ African elephants determined that handshaking faeces in a solution of isopropyl alcohol was effective for extracting the faecal progestagens (efficiency >90%).

4. Antibody-coated plates were stable for up to 3 months under a range of temperatures (4 to >38 °C) and the resulting faecal oestrous cycle progestagen profiles corresponded significantly to those of serum (r = 0·89, P < 0·01).

5. This field-friendly technique provided qualitative hormone data without the need for expensive equipment. Although developed for progestagen analyses in elephants, this approach should be adaptable to other steroids in a myriad of species. As such, it could facilitate how hormones are measured in species under field conditions and provide new tools for making sensible conservation management decisions.

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