HABITAT USE BY YOSEMITE TOADS: LIFE HISTORY TRAITS AND IMPLICATIONS FOR CONSERVATION

作者：Morton Martin L^*; Pereyra Maria E

来源：Herpetological Conservation and Biology, 2010, 5(3): 388-394.

• Bufo canorus
• core areas
• habitat splitting
• ovarian cycles
• Yosemite Toad

In the 1970s we studied habitat use and reproductive biology in Yosemite Toads (Bufo canorus) in the Sierra Nevada Mountains of California. Our surveys of four zones of terrestrial habitat in the post-breeding period provided a sample of 654 toads and revealed population and gender differences in distribution. Wet-meadow bottoms containing breeding pools were occupied by the majority (immatures and adults combined = 58%). Interestingly, the next most occupied zone was at the highest part of the meadow environment where it contacted talus slopes, more than 800 m from the nearest breeding pools (immature and adults combined = 26%). Adult females tended to be located there (108 of 237; 46%), but not adult males (7 of 225; 3%). Ovaries of post-breeding females were only partially developed before they entered hibernation. This suggests that storing enough energy during the brief high altitude summer to provide for both hibernation and reproduction in successive years is difficult and may cause irregular breeding in B. canorus, especially in females because they invest more than males in gonadal mass. We hypothesize that this asymmetry in energy requirements of adults may be the fundamental cause of differential dispersal.

• 出版日期2010-12