Commercial harvesting of giant lizards: The biology of water monitors Varanus salvator in southern Sumatra

Commercial harvesting of giant lizards: The biology of water monitors Varanus salvator in... The Asian water monitor Varanus salvator is the second-largest lizard species in the world (to > 1 m SVL, 2·5 m total, 20 kg), and is heavily exploited (> 1 million skins per annum). In the course of three trips between August 1993 and April 1995, we gathered information on 166 water monitors captured in southern Sumatra for the commercial skin trade. Relatively equal numbers of males and females were captured, but the males were almost all adults whereas half of the females were juveniles. Sex ratios and body sizes did not vary significantly among the three trips. Males grow larger than females, but the largest animals are not used in the leather trade. Males mature at around 40 cm SVL (= 1 m total, 1 kg), and females at around 50 cm. Maturation thus occurs at a small proportion of maximum size, as is typical for large species of reptiles. Adult males are more heavy-bodied than females, and have longer tails, but fat stores did not differ between the sexes. Prey items included crustaceans, rats and other varanids, but most lizards were kept for so long prior to slaughter that the stomach was empty of food. All adult-size males had active gonads, but testes were larger in April than in October. All adult females in the August and April samples were reproductively active, but less activity was evident in October. The egg-laying season extends from April to October (at least), and most female water monitors in southern Sumatra produce multiple clutches each year. Larger females begin to breed earlier in the year than do smaller animals. Clutch sizes ranged from five to 22, and were positively correlated with maternal body size. We measured stretched and dried skins from processed lizards to establish a predictive equation linking lizard SVL to skin width. The persistence of water monitors in southern Sumatra, despite intense harvesting, reflects the large area of suitable habitat with low human densities, combined with the monitors' ecological flexibility (in habitat and diets), their high reproductive rate (early maturation and frequent reproduction), and (perhaps) the concentration of commercial harvesting on adult males. At current levels, the commercial trade may extirpate varanids from local areas but will not drive the species to extinction. Biological Conservation Elsevier

Commercial harvesting of giant lizards: The biology of water monitors Varanus salvator in southern Sumatra

Loading next page...
Copyright © 1996 Elsevier Ltd
Publisher site
See Article on Publisher Site


  • Goanna
    Green, B.; King, D.
  • The reproduction and husbandry of the water monitor Varanus salvator at the Gladys Porter Zoo, Brownsville
    Hairston, C.S.; Burchfield, P.M.
  • Sexual dimorphism in snake tail length: sexual selection, natural selection, or morphological constraint?
    King, R.B.
  • Ecological and evolutionary implications of diet in monitor lizards
    Losos, J.B.; Greene, H.W.

You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial