2. Home rcttige 



Home range is here defined as the 

 area encompassed by the trap sites 

 of capture. Each trap site, as the 

 basis of tabulating home range, was 

 a square of sides 50 feet, or an area 

 of 2.500 square feel. Home range 



was estimated by multiplying this 

 area by the number of trap sites 

 within the area of capture. Onh 

 those rats which were trapped nine 

 or more times were used in this 

 estimation, The results are shown m 

 Table 2. 



Taui.i 2 

 Home range. 



l ag number 



Sex 



Number captv 



Number siles 



Home range (sq. yds. 



806 



F 



11 



3 



K44 



S12 



F 



13 



8 



4,170 



813 



f- 



15 



1 1 



6,110 



817 



F 



9 



7 



2,780 



825 



F 



12 



9 



4.170 



838 



M 



1 1 



5 



3.060 



844 



M 



11 



5 



1,390 



3. Comparisons of morphological 

 features. 



(a) Sex differences. 



Body measurements of males of 

 the island population were compared 

 to those of females by means of a 



'Student's t-test". As is shown in 

 I able 3'| a difference was found only 

 in body weight. Skull measurement-, 

 were compared in the same manner 

 There were no .significant differences 

 between sexes for all skull meavuK 

 mcnts taken. 



Tauli 3. 



Body measurements of island population. 





Mean 



ttesull 



Female 



Male 



Weight (gms.) 



Head-body 

 leneth (mm. ) 

 lail length 

 (mm.) 

 Hind-fool 

 length (mm.) 

 Kar length 

 (mm.) 



189.6 

 174.4 

 181.2 

 37.9 

 24.1 



213.4 

 178.0 

 186.9 

 37.4 

 23.4 



Difference al 5% level of significance 

 No significant difference. 



.. 



(b) Comparison of skull measure- 

 ments between Glcnnie. Uipps- 

 land and Portland populations. 



The results of a statistical com- 

 parison of skull measurements are- 

 shown in Table 4. Skull measure- 



ments used aie shown in the dia- 

 gram. Since the Glennie population 

 has larger skulls than the other IW> 

 populations, a similar comparison ul 

 some ratios of skull measuremenh 

 was made. This is summarised in 

 Table 5. 



j.1 



Vict. Nat Vol 88 



