Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

The Ecology of Moloch horridus (Lacertilia: Agamidae) in Western Australia

Eric R. Pianka and Helen D. Pianka
Copeia
Vol. 1970, No. 1 (Mar. 2, 1970), pp. 90-103
DOI: 10.2307/1441978
Stable URL: http://www.jstor.org/stable/1441978
Page Count: 14
  • Read Online (Free)
  • Download ($12.00)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
The Ecology of Moloch horridus (Lacertilia: Agamidae) in Western Australia
Preview not available

Abstract

Observations on the ecology of the Australian agamid, Moloch horridus, are described, and the literature on the species is reviewed. Its geographic distribution, which embraces most of the desert interior of Australia, corresponds closely to the distribution of sandy soils. With respect to food, Moloch is among the most specialized of lizards, since analysis of the stomach contents of 103 specimens revealed almost nothing but very small ants (Iridomyrmex). Moloch has a bimodal seasonal pattern of activity, with reduced activity in mid-winter and mid-summer. Evidence is presented for a spring breeding season, during which time individuals travel over great distances, probably increasing their chances of making mating contacts. At least some ovarian eggs become enlarged and yolked in autumn, but, since there is no evidence for autumnal oviducal eggs or egg laying, either sperm storage or arrested embryonic development may occur during the winter. Egg deposition occurs in the spring or early summer. Clutch size varies from three to ten, with a mode of eight. Females reach nearly twice the body weight of males. Natural longevity is often at least six years. Predators on the species include aborigines, bustards, and probably raptors and snakes. The ecology of Moloch is compared with that of its North American ecological analogue Phrynosoma platyrhinos. Although these two ant specialists are morphologically similar, there are a number of striking differences in their ecologies, which can be explained, in part, by the differences between the Australian and the American desert environments.

Page Thumbnails

  • Thumbnail: Page 
90
    90
  • Thumbnail: Page 
91
    91
  • Thumbnail: Page 
92
    92
  • Thumbnail: Page 
93
    93
  • Thumbnail: Page 
94
    94
  • Thumbnail: Page 
95
    95
  • Thumbnail: Page 
96
    96
  • Thumbnail: Page 
97
    97
  • Thumbnail: Page 
98
    98
  • Thumbnail: Page 
99
    99
  • Thumbnail: Page 
100
    100
  • Thumbnail: Page 
101
    101
  • Thumbnail: Page 
102
    102
  • Thumbnail: Page 
103
    103