May 20, 2025

    We are just into hummingbird season. We saw the first bird about a month ago. We had to rework the spreadsheet, it wasn’t properly accounting for feeders not getting emptied for multiple days. We were also just dividing the syrup volume brought in by 2, which wasn’t quite correct either.

This was shot on 5/18/2025 at about 4:00 PM. Really dramatic thunderstorm, as well as the hummers

This was shot today at 7:00 AM. Still just few hummers.

Here’s the current overall spreadsheet so far this year. We’re up to about 100 birds.

Let’s go behind the scenes! First is some constants that are needed. This year we added the “Cup of Syrup to Sugar Oz Conversion”. We just measured the volume of syrup made from 2 cups of sugar and 4 cups of water. We got 5 cups of syrup. Therefor we get 1.25 cups of syrup from 1 cup of sugar. Taking into account the fact that a cup of sugar weighs only 7 ounces, we arrive at 2.8 ounces of sugar per cup of syrup. The conversion cell is O8 in spreadsheet row-column lingo.

Now we’ll go interesting cell by interesting cell across the sheet. 

Note that when you have a formula open for edit, that Apple’s Numbers spreadsheet color codes the cells referenced. Here the Sugar out is blue, the syrup in is orange and the constant Syrup to sugar conversion in the top right of the spreadsheet is purple.

The first one is the sugar used per day. This is complicated because we measure the sugar out and the syrup brought back in. All we can measure is how much syrup we bring in. Here’s where we use O8, $O$8 means the row and column don’t change no matter where you put this cell in the sheet. We mulitply the syrup brought back in by the conversion factor and subrract that from the sugar used to make the outbound syrup. 

Next is “End of Day”. This is easy, we just look down one row, and if the date has changed, we’re at the end of this day.

“Feeding Interval in Hours” had to be fixed. Martin had been using just simple VLookups to find the previous end of day entry. Unfortunately, if you do it that way, the spreadsheet gets extremely slow and impossible to use if it’s got more than about 100 rows. So the range-limited Lookup is used now to go back 4 syrup reloads. We hope to never have to do more than 4 per day!

“Ounces of Sugar Per Day” is complicated! We have to look backward and forward to find all the days that match this one and if they match we sum up each reload’s sugar used to get this number. There aren’t any days with more than 1 reload yet, so you can’t see multiple rows with the same value yet.

Finally, “Birds per day”. This is really if the hummingbirds were only feeding here, how many would we be feeding. We only calculate this at the end of each day and it also uses the hummer weight from the constants section.