I've had 6 assorted "Perky Pet" brand hummingbird feeders up scattered around
the porch and yard all winter as usual, and as usual the place swarms with a
dozen or so Anna's all winter long. Over the years, I've noticed that when
the feeders are full and/or when one is just refilled, the pace or urgency to
attend that one or those newly filled feeders initially drops off and the
little buggers opt for those half full and especially those nearly empty.
So, I guess I am wondering if the hummingbirds "notice" when a feeder is full
as opposed to one that is nearly empty. If one is full, then maybe they
"know" they have plenty of time. Those getting light then take on a
precedence less any one individual hummer might miss out to one of the other
competitors. Those feeders that are down to their last drops really do get
attacked the hardest until they're dry.

At first, I thought maybe the 4:1 water/sugar mix just had to sit there and
'ripen' for a few days in the feeders that were full to the top. Then I
tried an experiment this winter. Just fill some of the feeders half full or
less and see what happens. The moment I refill feeders half or less and
rehang them, the hummingbirds are on those feeders in an instant. I can't
even get back in the door or even back off 3 feet before they attack since
all they do all winter long from the first hint of dawn to the last hint of
dusk is constantly commute back and forth between perching, pooping, and
hiding in the rhodies and zipping to the feeders only a few feet away. I've
frequently seen as many as six Anna's all happily getting along in one of my
rhodies nearest the back porch feeder stations at once. It's getting to be a
mess in there :-)) This experiment has been going on now for some time and
randomly with the feeders in various locations, so I am starting to conclude
that they really are using visual clues to evaluate the amount of 'nectar'
remaining before the 'flower dies' and have to proceed to another. Any
thoughts?

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Richard Rowlett
Bellevue (Eastgate), WA, USA

"Discovery consists of seeing what everybody has seen and thinking what
nobody has thought" --Albert Szent-Gyorgi (1893-1986).
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