Body Temperatures of Rain Forest Mammals — Rudd 
473 
capture of 377 individuals of 21 species with 
a total capture-recapture record of 2,6l6. Many 
individuals were recaptured five or more times. 
To minimize trauma of handling, temperatures 
were never taken oftener than once a week in 
frequently captured animals. Normally, how- 
ever, the vagaries of recapture did not allow 
for temperature readings oftener than once 
every three or four weeks. A few additional 
temperature measurements came from individ- 
uals collected away from the grid area. 
All temperatures were taken rectally with a 
Schultheis rapid-recording thermometer read 
to 0.1° C. Insertion of the entire bulb well past 
the lip of the column was simple enough for 
all but the smallest species (Tylonycteris ) . 
Even so, the temperatures recorded for this 
small bat are believed to be accurate. Data from 
obviously ill or moribund animals are not in- 
cluded in Table I. However, where these data 
might suggest critical temperatures they are in- 
cluded later in the discussion. There was no 
direct attempt to determine critical tempera- 
tures nor to determine metabolic responses to 
changing ambient temperatures. Confidence 
limits were calculated only when the sample 
constituted 10 or more individual readings. 
RESULTS AND DISCUSSIONS 
I hdividual V aviation 
Single healthy individuals irrespective of sex 
regularly varied within a two or three degree 
range over long periods of time. Yet the range 
on the temperature spectrum, while being con- 
sistent for individuals, often differed between 
them. Consistent behavioral differences seemed 
to correlate well with these individual patterns. 
The following tabulation shows repeated tem- 
perature readings of single individuals over 
many months. The individuals were selected 
because their behavior deviated sufficiently 
from the norm of the species to warrant men- 
tion in field notes. Only animals of the same 
sex and equivalent weigths are compared. 
Rattus rajah 
$ Docile 36.5; 36.5; 35.1; 36.3; 35.5; 
36.2; 37.8; 35.9; 36.8; 37.9; 36.4 (x = 
36.44;; r= 35.1-37.9) 
$ Aggressive 36.4; 38.7; 38.9; 38.0 (x = 
38.00; r = 36.4-38.9) 
Rattus muelleri 
$ Docile 35.0; 35.4; 35.2; 35.8; 36.3 (x = 
35.56; r = 35.0-36.3) 
$ Aggressive 37.8; 37.3; 38.6; 38.1; 38.1; 
36.4 (x== 37.71; r = 36.4-38.6) 
Rattus sabanus 
$ Docile 35.3 ; 36.1 ; 37.5 ; 35.2 ; 34.8; 36.3; 
35.3; 37.4; 36.8; 36.5; 37.9 (x = 36.28; 
r r= 34.8-37.9) 
$ Aggressive 36.6; 36.2; 37.3; 37.8; 37.5; 
35.8; 39.2; 39.4; 38.4; 38.3 (x = 37.65 ; 
r = 35.8-39.4) 
$ Docile 36.6 ; 36.7 ; 36.8 ; 36.9 ; 36.2; 36.3 ; 
34.8; 37.2 (x = 36.45 ; r = 34.8-37.2) 
9 Aggressive 35.2; 37.1; 37.4; 35.4; 37.1; 
37.3; 36.1; 36.0; 38.0; 37.8; 38.2; 37.9; 
38.9 (x = 37.10; r = 35.2-38.9) 
In these instances mean temperature readings 
between individuals of like species, sex, and 
weight varied as much as 1.5° C. Yet, essential 
consistency characterized the body temperatures 
of these and most other individuals of groups 
generally regarded as having a high ability to 
regulate temperature. Only in one group other 
than rodents are repeated readings available. 
In the insectivore Hylomys the temperature 
range in individuals was slightly wider than in 
most rodents. One adult male with seven read- 
ings showed a variation of 2.8° C (33.6°- 
37.4°); an adult female with eight readings 
showed a variation of 3.0° (35.1°— 38.1°). 
The possible influence of the trapping regime 
on temperature was checked in 16 repeatedly 
taken individuals of four species of Rattus. 
Since trapping and handling procedures were 
standardized, it was assumed that individuals 
captured 20 or more times might become 
habituated and therefore show less variation in 
temperature. The first three and the last three 
temperature readings were graphed against 
body weight. Although changes in both mea- 
sures occurred, in no case was there a consistent 
pattern of temperature change. The range of 
temperature remained as great after several 
months of trapping as at the beginning. 
Relation of Temperature to Reproductive State 
and Sex 
In the first weeks of trapping a few indi- 
viduals showed signs of recent lactation. How- 
