Thursday, January 3, 2013

Surprising Patterns of Food Consumption

For the past two years I've systematically measured the consumption of bird foods here in the land of Cary BirdCam.  The basic methodology is simple: measure each amount added to feeders.  And now that 2012 is complete I can start crunching the numbers and evaluating patterns.  The big story in 2012 was reduced consumption of the big ticket items, and greatly reduced consumption at that.

For one, I put out 130.3 pounds' worth of sunflower seed this past year than the one before---a 28% reduction.  For those in the cheap seats, that's more than three 40# sacks, or a savings of over $129 US.  Similarly, safflower seed consumption was down 73.7# and suet 29.2#.  And even the small fry stuff like peanut butter, peanuts and suet nuggets was off pace by similar margins.  All in all, I realized something like $350 in savings this past year.  That's wonderful news: I still got the birds, and I saved big bucks.

So what's going on?  If I saw this drop only in sunflower seed, I would unhesitatingly claim the benefits of managing squirrels.  But that's plainly not the case.  Birds are not likely to be eating less per bird---in terms of fewer calories per day.  Can I assume there are fewer hungry birds, or at least fewer visits per bird to the feeders?  Maybe.  Indeed I have seen fewer goldfinches; that's one seedeater.  But there's also an argument that my anti-squirrel measures have tended to lock out larger birds from most of the seed and suet feeders, and just possibly this is the major cause.  Unfortunately, I don't really know.  I would need to have solid comparative visit data by species for both years.

Well, no matter.  I have plenty of birds here, and I have more greenbacks in the wallet.  And at the end of the day, that's really all that matters.  But I think I want to see data for the experiment shall continue.

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