著者

LOVICH JEFFREY E. PUFFER SHELLIE R. AGHA MICKEY ENNEN JOSHUA R. MEYER-WILKINS KATHIE TENNANT LAURA A. SMITH AMANDA L. ARUNDEL TERENCE R. BRUNDIGE KATHLEEN D. VAMSTAD MICHAEL S.

出版者

日本爬虫両棲類学会

雑誌

Current herpetology (ISSN:13455834)

巻号頁・発行日

vol.37, no.1, pp.40-57, 2018

被引用文献数

3

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<p>Agassiz's desert tortoise (<i>Gopherus agassizii</i>) reaches the southern edge of its range in the Sonoran Desert of California. The reproductive ecology of this wide-ranging species is understudied here compared to populations in the adjacent Mojave Desert. Understanding potential geographic variation in reproductive ecology is important for effective management of conservation-reliant species like <i>G. agassizii</i>. We studied the fecundity and clutch phenology of female <i>G. agassizii</i> at two study sites in the Sonoran Desert region of Joshua Tree National Park over five years (1997–1999–2015–2016) spanning two of the strongest El Niño events on record and an epic drought. Across all years, mean clutch size was 4.3±1.5 eggs, mean clutch frequency was 1.78 clutches/female/year, and mean X-ray egg width was 36.51±1.56 mm, all of which are comparable to other published studies both in the Sonoran and Mojave deserts of California. Our results generally support earlier published findings that <i>G. agassizii</i> utilize a bet-hedging strategy of consistently producing small clutches almost every year, even during times of low annual primary productivity. A regionally warmer climate in the Sonoran Desert of California appears to have an effect on the timing of egg production, as the earliest dates of egg visibility in our study (April 6) were approximately two weeks earlier than the earliest dates reported for <i>G. agassizii</i> in the Mojave Desert. Shelled eggs were no longer visible in tortoises after mid-June in all years but the El Niño year 1998, when eggs were visible until mid-July.</p>