Since my last post, when I reported sugar consumption at my feeders of 24
g/day average 17-Apr to 4-May, the rate has increased to 33 g/day average
5-May to 17-May, then to 65 g/day average 18-May to 23-May and again 24-May
to 1-Jun.



If I assume that the feeding patterns remain somewhat the same (on 4-May
there seemed to about 24 birds in the evening), then the head count has
increased by about 40 birds over two weeks or so. This could be the first
crop of juveniles, plus females taking a break from nesting.



If I assume that the birds burn about 10 kCal/day (a range of 7-12 kCal/Day
is given at http://www.wintuaudubon.org/Documents/feeding_hummingbirds.htm),
then the 1 g of sugar (3.75 kCal) per day per bird figure would indicate
that they are getting about one-third of their calories from my feeders -
this seems to be a reasonable risk / reward ratio. I am going to use this
figure in the second post.



Dave Nuttall

N.W. Bellevue, WA

MailTo:dave_nuttall at yahoo.com