How Many Times Does a Robin Sing?
(Calculating songs per minute, hour, day, season)

Background
 Did You Know? Robins can sing for long stretches without stopping. Humans need to pause to take a breath now and then when we are singing or speaking. This is because our sound is only produced as we breathe out. But birds can make sounds while breathing both in and out!
Have you ever counted the songs sung by one of your backyard birds? Margaret Morse Nice spent a whole day counting every single song sung by one backyard Song Sparrow. She first tried this on February 22, 1935. The sparrow sang his first song at 6:42 am, and in the next three hours Dr. Nice counted 679 songs! But then a cold wind made him stop singing, and she quit counting for the day. On May 11, 1935, she tried again. This time he started singing at 4:45 am, and in the next 15 hours Dr. Nice counted a total of 2305 songs! (Why do you think the first song Dr. Nice heard on May 11 was almost two hours earlier than the song she first heard on February 22?)

Our Experimental Challenge
How many songs would a ROBIN sing over a single day? We searched, but couldn't find anyone who had actually counted. We thought we could come up with a reasonable answer ourselves. We know that robins are one of the first species to begin singing every morning. In late May, they normally begin singing over an hour before sunrise. They sing the most early in the morning and at evening twilight after sunset. They sing the least around noon. We thought we could figure out approximately how many songs they sing each hour through the day, and add these up.

To figure out how many songs robins sing during the hours when they sing the most, we listened to Lang Elliott's bird recording, "Know Your Bird Sounds: Volume 1." That's when we realized that robin songs are not as easy to count as Song Sparrow songs!

 Listen to the Robin's Typical Song Listen to the Robin's Continuous Song

Robins sing a song that can have long or short pauses between phrases. We decided for the purposes of this experiment we would count each song as a new one when he made a longer pause. Counting this way, we heard 8 "typical" songs in 22 seconds, which is a LOT of songs!

If the robin continued to sing at this rate for an hour, how many songs would he sing in an hour?

It seemed impossible to count songs when he was singing his "continuous" song — the one robins sing at dawn — because the notes ran together so fast. A continuous song has few or no pauses, so we might think a robin was singing only one song per hour at dawn. This doesn't seem like a reasonable comparison because the same bird might sing over a thousand times later in the morning when he was actually singing fewer notes!

So how could we decide where one song ended and another started? We suddenly realized that this is probably the reason ornithologists don't publish the number of robin songs sung in a day. They're just too hard to count!

Now it's your turn to be the scientist. Listen to the recordings of robin songs. Once you decide on a good way to count the continuous songs and the typical songs, try the activity below.

Activity: Conducting Your Own Robin Song Study
Materials

Instructions
At least once a week, record and count the number of times a robin sings. (Try to listen for 5 to 10 minutes each time.)

Analyzing Your Data (Discussion and Journaling Questions)

• Does the frequency of singing change during the season? If so, try to hypothesize why.
• Do robins seem to sing more at a particular time of day?
• Can you notice whether their song changes according to the stage of the nesting cycle?
• Male robins are said to sing the most while females are incubating eggs. How would you explain this behavior? Does your bird follow this rule?
• When are the songs the longest? When are they shortest?
 One Scientist's Estimate Journey North's Robin Expert Laura Erickson guessed about how many times a robin would sing in a season. She timed the songs in Lang Elliott's recording of a robin's typical song (see above) and calculated that at that rate the robin sang about 1300 songs every hour. If he was singing about 10 hours a day during his heavy song days, that means he sang about 13,000 songs on those days. Robins from the eastern U.S. and Canada sing for about 120 days during the breeding season. Laura made the assumption that about half of those days are heavy singing days. So she calculated that they sang about 780,000 songs during the heavy singing days. If they sang half as many songs during the slow times, or 390,000 songs, then they sang a total of 1,170,000. She decided to round this down to a simple one million songs a season. That's a LOT of singing!

Digging Deeper: A Grand Robin Opera
In March, just about everywhere in North America robins start to sing! Their songs are so popular that we humans sing songs about their songs, such as "When the Red-Red-Robin Comes Bob-Bob-Bobbing Along" and "Rockin' Robin." Close your eyes and listen to the chorus of robins (and other birds) in the morning or evening. How does it make you feel? What does it remind you of? What words would you use to describe it?

Here's what an ornithologist named Edward Howe Forbush wrote in 1925:
"On every vernal morning a wave of Robin song rises on the Atlantic coast to hail the coming day, and so, preceding the rising sun, rolls across the land until at last it breaks and dies away upon the distant shores of the Pacific Ocean."

Another authority on robins named Len Eiserer wrote this in 1976:
"Oh, if only we humans could cast off the blindfold of spatial limitation and actually perceive this daily wave! We surely then would witness one of the great dramatic events of Nature. Still, whether we perceive it or not, this grand Robin opera continues to salute each summer dawn as it has faithfully done since time immemorial."

National Science Education Standards

• Plan and conduct a simple investigation.
• Use data to conduct a reasonable explanation.
• Scientists use different kinds of investigations depending on the questions they are trying to answer.
• Scientists develop explanations using observations (evidence) and what they already know about the world.
• Behavior is one kind of response an organism can make to an internal or environmental stimulus.