1911-12.] Body Temperature of Diving and Swimming Birds. 35 
16 0, 5 C. in the shade. Care was taken that they should not be unduly 
exercised before the thermometer was introduced. 
Ducks. Drakes. 
I. 
. 4D1 c. 
I. 
. 41-6 C. 
II. 
. 42-0 
II. 
. 41-8 
III. 
. 41-6 
III. 
. 41-1 
IV. 
. 41-7 
y. 
. 4D4 
Mean 41 5 
yi. 
. 41-8 
Mean 41 - 6 
Here there is practically no difference between the mean temperature of 
the tame ducks alive and that of the wild ducks immediately after being 
shot. In the latter there is a greater range (minimal 40 o, 4, maximal 42 0, 6), 
but this one would expect considering that in the one group the observa- 
tions were made on the same day and at the same hour, and in the other 
under widely different conditions regarding hour of day and outside 
temperature, etc. It is not probable, therefore, that the difference in 
temperature between the Sulidse and the Phalacrocoracidse is to be entirely 
accounted for by the methods adopted in taking the temperature, although 
it may be to some extent. 
Y. Summary. 
Observations were made on the body temperature of a large number of 
diving and swimming birds of eighteen different species in the Orkney 
Islands and Firth of Forth, Scotland, and on and around Cayuga Lake, N.Y., 
U.S.A., immediately after they were killed by shooting. 
1. In all the species' examined, where the sex was determined, it was 
found that the rectal temperature of the male was slightly below that of 
the female. 
2. Of the orders examined the highest temperatures were found in the 
Longipennes and the lowest in the Tubinares. When arranged according to 
body temperature the series does not run parallel with the zoological series. 
In conclusion, I wish to express my indebtedness to Dr H. D. Reed and 
Dr A. H. Wright for help in identifying the specimens obtained from 
Cayuga Lake and the surrounding district. 
{Issued separately February 16, 1912.) 
