The British Herpetological Society

The Herpetological Journal is the Society's prestigious quarterly scientific journal. Articles are listed in Biological Abstracts, Current Awareness in Biological Sciences,Current Contents, Science Citation Index, and Zoological Record.

The 2017/18  impact factor of The Herpetological Journal is 1.268

ISSN 0268-0130


pdf 03. Changes in plasma oestradiol, testosterone and progesterone concentrations during an annual reproductive cycle in wild Aldabra giant tortoises (Aldabrachelys gigantea)

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https://doi.org/10.33256/hj30.4.197201

pp. 197-201

Authors: Maya S. Kummrow, Richard Baxter, Gabriela Mastromonaco, Nancy Bunbury, Marcus Clauss, Dennis Hansen & Jean-Michel Hatt

Abstract: Aldabra giant tortoises (Aldabrachelys gigantea) are currently listed as Vulnerable on the IUCN Red List of Threatened Species. However, negative impacts of sea-level rise are predicted to result in an overall population decline of 40-65 % over the next 100 years, rendering the species Endangered. Captive propagation is an important tool for in- and ex-situ species conservation, but breeding success outside the tortoises’ native island habitats has been very limited. Until now, the reproductive cycle of Aldabra tortoises has only been described in anatomic and behavioural studies. During a one-year period, plasma of four female and four male wild tortoises on Aldabra Atoll were examined monthly for levels of gonadal steroid hormones (oestradiol, testosterone, progesterone). Plasma oestradiol and testosterone values as well as meteorological data of the sampling period corresponded to previously published reports on seasonal changes in anatomy, behaviour and climate on the Aldabra Atoll.
Seasonal changes in plasma testosterone were evident in males, with high values from January through April, reflecting previously described testicular growth and breeding season, followed by a nadir in August and September. In females, plasma oestradiol levels displayed seasonal changes, coinciding with reported ovarian growth from January to May. The obtained data provide prerequisite knowledge for endocrinological monitoring of reproductive processes and management of breeding programs, both ex-situ as in-situ, to establish reserve- and rewilded populations.

Keywords: Aldabra giant tortoise, Aldabrachelys gigantea, reproduction, seasonality, steroid hormone

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IMPORTANT NOTE - JUNE 2020

Please note that as from Volume 31 Number 1 (January 2021) on, the Herpetological Journal will be available as an online publication only - the last print edition will be Volume 30 Number 4.   

Aligning with this change, it is now no longer possible to purchase a subscription that includes a print copy of the HJ.  All members who have existing HJ print subscriptions that remain active as at end June 2020 will receive the full four 2020 print editions.  New subscribers or renewals after this time will only have option to subscribe to the online only subscription package.  Subscription pricing has been amended to reflect the content changes.