Behavior of Yaranus Komodoensis 
303 
Table 1. Population parameters of adult 
Varanus komodoensis (Komodo only) 
Habitat type 
Approximate 
Area 
(Km2) 
Approximate 
Monitor 
Population/ 
Km2 
Tropical deciduous forest 
57 
14 
Forest — savanna ecotone 
10 
16 
Savanna 
103 
9 
Tropical steppe 
60 
6 
Core Areas 
Most studies of carnivorous lizards show 
that individuals spend approximately half 
their time in a fairly small core area (Rand, 
1967), compared to the total area visited 
during the course of a day. The core area is 
that part of the total range most heavily 
used and has the least overlap with ranges 
of other individuals of the same species. 
The core area for a mature Komodo moni- 
tor is where it spends most of its time and 
in which it is concerned with predation on 
live animals and maintenance of the pair 
bond. Often included within the core area 
are one or more knolls or hills extensively 
used by the resident. Collectively these sites 
constitute the activity center of the individ- 
ual's core area and are important in thermo- 
regulatory behavior and surveillance. 
Few individuals (described below) were 
found to have activity patterns fitting the 
definition of core area, at least when applied 
to a time period of several months. The 
Komodo Island population is comprised of 
many transient and relatively few resident 
individuals. Only a few of the 300 individuals 
observed in our Komodo study area were 
regularly seen during the study period. Most 
remained in the area from only a few days 
to a few weeks. All residents were large 
adults, while transients included the whole 
range, from hatchlings to unusually large 
animals (Table 2). Almost none of the transi- 
ents were adult females. Thus, the transients 
(including many mature males) represented 
a dynamic faction in the local population, 
with new individuals constantly entering new 
Table 2. Size and sex of transient and resident 
V. komodoensis in the southern part of Loho Liang, 
Komodo, 1969-1970. 
Sizes Classes 
Residents 
Transients 
( Total length 
in mm) 
(freq. and sex) 
(freq. and sex) 
1.1-1.5 
M 
1 
12 
F 
0 
5 
1.6-2.0 
M 
1 
14 
F 
2 
2 
2.1-2.25 
M 
1 
4 
F 
1 
1 
2.6-3.0 
M 
1 
0 
F 
0 
0 
Totals 
7 
38 
areas and interacting with residents and 
other transients. 
The core areas of resident male and female 
adults often broadly overlapped. In such 
cases there is believed to be a pair bond (see 
below). Core area overlap of presumably 
pair-bonded individuals was estimated as 
nearly 80 percent in the two cases for which 
sufficient data were available. Overlap be- 
tween nonpair-bonded individuals (n=27) 
is 5.7 percent. 
Although adult male oras generally stay 
within their mutually exclusive core areas, 
they are often seen in one another’s scaveng- 
ing ranges (see below). The fact that carrion 
occurs within the core area of a resident 
adult male does not discourage intrusion of 
the core by nonresidents of any sex or size. 
Because all long-term residents of estab- 
lished core areas are adults, it can be pre- 
sumed that residency does not normally occur 
until the individuals are at least 7 years old. 
Evidence suggests that some large V. 
komodoensis may live around one core area 
for periods as long as 25 to 40 years (Auffen- 
berg, MS). Unfortunately, it is not known 
how residency is established or lost, or what 
behavioral and physical characteristics en- 
able certain individuals to become residents 
Presumably aggression plays a major role. 
