July 12, 1963 
Dear Bob, 
Since Karsranna and Kaxlne are quite busy today I a*^kln£ the liberty of 
writing to make eure that you raoelve the information ft the Sooty Tom in 
plenty of time. This letter will presumably reach you early next week and 
if at that time you find that you need additional details please let ue know 
If ^his la the ease please state very specifically what infor* 
mation you need. We will send it to you at the hotel on Viake as soon as we 
are able to oon^ile what you request. 
The incubation period of the Sooty Tern Is 26 days. This fact was determ¬ 
ed by J, B, Watson in 190? from observations made on 16 nests on the Dry Tox^ 
tugas* The figure is quoted widely in other literature but I hare been unable 
to locate any indication that other workers have attempted to verify it. At 
that time the same persdb r^oirtod that the young were completely feathered 
at the end of 30 days and " as the birds get older they begin to fly short 
distances. At the end of 35 days they can cover 30 to hO feet very rapidly 
by a series of fl>’lng hops." Sprunt who also studied ttie birds on the Dry 
Tortugas says that the young are on the wing in two months. Watson also 
states that incubation Is by both saxes with each bird sitting for 24 hours 
wt^ the ehangs-over oooxxrrlng at nl^t. After hatching the young are brood¬ 
ed by a parent for the first three days; this careful protection Is followed 
by feeding by both parents and a considerable Increase in mobility of the 
yo’jng birds. They learn to i*un to the bushes ren;ai.'iing motionless after 
sticking their heads into the ctetoh of a bush or depressing the body against 
any convenient object. The parents soon leam to recognlxe their own young 
and the young leam to respond to their own parents, Saoh parent feeds its 
own young and attacks the young of any other bird which invades its territory, 
^Is leads to many fights among the adults and much morta^lity among the 
young, 
I hope that this information is what you want and will provs useful. If 
not let us know and we will pull together and send anything else you De4d if 
available. 
Sincerely, 
Robert A. Sundell 
