RECORD: Darwin, C. R. 1856.10.15. Talking with Mr Thompson. CUL-DAR205.2.145. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 5.2022. RN1
NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR205.2 contains notes on means of distribution.
The brown crayon number '18' indicates that this document was filed by Darwin in his portfolio for the subject of Migration.
John Thompson (1810/11-1859), Superintendent of the Zoological gardens in London from 1852-1859.
[145]
18
Oct 15 /56/ Talking with Mr Thompson & several Keepers it seems time very uncertain at which Hawks, Eagles & Owls throw up pellet. Sometimes 24 hours, some after 48 or 72, or even 4 days & Mr Thompson alone thinks even longer viz a week- Thinks owls throw up rather sooner than Hawks.
Say even 50 hours
say per hour 25 miles 25 / 1250 miles
say 60 hours 250 / 1500 miles.
It is quite possible Hawks free wd throw up quicker?
It deserves notice that seeds thus sown wd be well manured.
[145b]
Even if Hawk blown into sea, wd. float some distance: I have seen a Polyborus cast up by sea.—
All Hawks & owls & Vultures (except Condor) throw up pellets in Zoolog. Gardens. (So do Shrikes but these do not concern me)
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 25 September, 2022