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 2013...so the experiment shall continue.