be no older than four months; if one accepts their hatching as having 

 been in the March-April period of this year. Such small specimens 

 have been observed several times by Lhe members of the expedition. 

 However, the youngest of the monitors caught by us have attained a 

 length of 115 to 125 cm., i.e., they have been 16 to 18 months old 

 and probably hatched in March and April 1961. The measurement and 

 marking of the young monitors which we did (see table 1) will permit 

 in subsequent captures obtaining data on migrations and intensity 

 of their growth in nature. The marking of the animals has been done 

 by a standard method, by cutting off the terminal phalanges of the 

 digits. The sites of release of the marked monitors on the Island 

 of Komodo are indicated in the figure. 



Judging from the data that are to be had, males make up a 

 considerable part of the monitor population on the island of Komodo. 

 Of the 17 specimens acquired here by Americans in 1926, 14 were males, 

 and there were only 3 females (Dunn, 1927). Judging from the measure- 

 ments of this author, two skeletons found in abandoned traps set by 

 local residents belonged to males. Proceeding from the dimensions 

 of the body (females of the mammoth monitor do not exceed 2 m. in 

 length), six of the nine skins from the Island of Komodo examined 

 by us at the Bogor Zoological Museum on Java also belonged to males. 

 Two males from Komodo were delivered in 1935 to the zoological garden 

 of the city of Surabaja (Tanzer and Heurn, 1938). Finally, among 

 the 26 specimens caught on Komodo by our expedition, ?2 were males 

 and 4 females. Thus, at least 46 of the 56 monitors acquired on the 

 Island of Komodo at various times, i.e., more than 80 percent have been 

 males. In other words, the ratio between the sexes on this island 

 is approximately 6:1. It may be noted that chiefly males have been 

 acquired in different zoological gardens, the same as on the islands 

 of Rintja and Flores. The clear predominance of male specimens 

 in the island population of monitors apparently is no accident, but 

 rather reflects the actual ratio of the sexes existing in nature. 

 It is possible that the sharp reduction in number of females is 

 the manifestation of a special mechanism of regulation of the number 

 which prevents overpopulation of the monitors on the island. The 

 small territory of the island, together with the limited amount of 

 food (carrion), as well as the great length of life of the monitors 

 themselves, might fully play the role of factors that have 

 produced in the process of evolution the selection of such a mechanism. 



Feeding Habits 



The feeding habits of the giant monitor have been studied rather 

 fully. According to the data of Burden (1927, 1928), Hoogerwerf 

 (1954, 19^8), and Pfeffer (1959), and also according to the observa- 

 tions of our expedition, the monitor's food is composed primarily of 

 the carrion that appears more or less regularly on the islands as a 

 result of the natural death of the red deer that have been guided here 

 ( Cervus r usa timorensis ) , of the wild hogs ( Sus s c rofa subsp), and of 

 wild buffaloes and horses. The specialized sense of smell, together 



