Predation of incubator birds (Megapodius freycinet) by Komodo dragons (Varanus komodoensis)



A short study was made of the nesting habits of a species of megapode, Megapodius freycinet on the island of Komodo. The birds were found to build giant nesting mounds (0.95 × 7.15 m) in scrub and woodland close to the seashore or alongside river beds; 23 active and 19 abandoned mounds were located in an area of 250 ha.

The mounds were apparently added to from year to year, and consisted of dry sand and soil, plus leaves and sticks in most cases. The upper parts of the mounds were invariably exposed to the direct rays of the sun; the temperature within the active mounds was 33–37° C and slightly less in mounds not in use by the birds. According to the local people the nesting season of the megapodes extended from late August to November, and the chicks were hatched before the arrival of the rains in December. Up to four eggs had been recovered from a single mound.

The active mounds were all spaced apart by at least a 100 m, and the closest ones were usually separated by a river bed. This pattern suggested the species was territorial. One or two birds were often seen scraping at a mound or feeding close by, and their behaviour was recorded.

The Komodo dragon, Varanus komodoensis, was a frequent visitor to the nesting mounds of the megapodes, and was able to burrow into them and steal the eggs.