We also have a property on the south side of Oak Bay, between Port Ludlow
and Port Hadlock. I have had feeders out there for several years, but did
not start weighing them until this year. Currently I have five feeders (two
96 oz, two 48 oz, and one 32 oz) deployed, and am using 50 Brix sugar
solution. There is a large Rufous population, with activity at the feeders
all day long, and a mass feeding frenzy in the late evening.



Peak sugar consumption has been about 800 g/day average 14-May to 26-May,
and has declined to about 700 g/day average 26-May to 31-May. The peak
corresponds to about 3000 kCal/day - enough for two adult female humans. If
I assume that each bird requires 10 kCal/day, and that all their energy is
supplied from the feeders, then the peak population would be about 300. If
they follow the same pattern as in Bellevue (about 1 g/day of sugar) then
the peak would be about 800. My guess is that the females nest nearer to the
feeders than in Bellevue, and hence utilize them more, so the peak number is
probably about 600.



I think that the recent peak then drop-off in sugar consumption is due to
the first batch of young fledging, and then some of the adults feeding up
and moving on northwards. How to keep tabs on all this activity is the
subject of the third (and final) post.



Dave Nuttall

Oak Bay, WA

MailTo:dave_nuttall at yahoo.com