Thursday, November 11, 2010

Of Mantids and Hummingbirds

Dino noticed this hummingbird before the praying mantis did - this bird had evidently perished while securely perched on the fence wire.  Its little feet were still clamped shut and held the bird pendant.  Ever of a scientific bent, we left it. 

Some days after its demise, along came a hungry praying mantis.  We did not know that mantises would eat carrion.

We are still feeding huge swarms of hummers.  Dino has been tracking the number of hummingbird feeders we fill, and determined that in the month of October we put out forty two gallons of hummingbird nectar (1:4 sugar water solution).  This represents a 50% increase in hummingbird food over the months of August and September. 

Using a calculation of 500 birds/gallon/day, we figure that we are feeding 677 hummers/day.  On heavy days, we can easily see 50 or more birds at a time.  I'm not sure where Dino originally found that calculation, but the website Field Guide to Hummingbirds repeats a similar one:  "One fluid ounce of 1:4 sugar water weights about 35.5 grams (approximately 20% more than its plain water counterpart).  We'll average the weight of the birds to 3.5 grams, or about 10% of the weight of a fluid ounce.  Multiply that times by 265% for average consumption and we get 0.265 fluid ounce of 1:4 feeder solution per bird per day, which we'll round down to 1/4 fluid ounce per bird per day.  This multiplies out to around 32 smallish hummingbirds per 8 ounces of 1:4 sugar water, 128 per quart, and 512 per gallon."  Since Anna's hummingbirds are somewhat larger than "smallish", using 500 birds/gallon seems reasonable.

*Note - the author of the blog noted wrote the Peterson Field Guide to Hummingbirds book, so believe her info to be good.

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