Don’t Mock the Mockingbird

With a classic lullaby, a best selling book, a chart topping pop song and a university run student publication, the northern mockingbird has sold its name to every corner of the industry. Yet, even with its ubiquity and name recognition, the mockingbird has been able to keep its private life hidden behind curtains–something Hollywood should learn from.  After a quick and non-scientific survey of the general populace, I came to the conclusion that outside of its more famous exploits, no one on campus had a clue who or what the mockingbird was! So today, as a favor to my readers and myself, I decided to do a little bit of my own “paparazzi-ing” to enlighten people to the world of this mysterious individual.

My first surprising discovery was how common northern mockingbirds (Mimus polyglottos) actually are. After walking just a few steps into the engineering quad at Rice University, I was able to find a pair of these birds hobbling across the lawn and flying around each other in quick fashion. They were physically inconspicuous – having a relatively small body size and a body shape that is very “thrush-like” but thinner; in fact, it was only when they opened their wings did their dull gray-brown coat give way to the glaring white feathers hidden in the folds of their wings. Yet, as they darted between bushes and grass while zigzagging around each other, it became obvious that their behavior was anything but “inconspicuous.” In fact, these birds were fairly loud and had a large variety of songs. But as a whole, the pair of lovebirds seemed to mesh perfectly together as they danced across the field. Of particular interest was the reappearance of the white feathers as they expanded their wings, a byproduct of their flight.

Taking my observations to more scientific sources, I found many studies on these bird’s andtheir songs, yet surprisingly little else. This piqued my interest since it isn’t very often we will see such an emphasis on one single subject. So what exactly is so interesting about the songs of these birds? It seems that these birds are like the you-tube stars of the bird world, they can cover any song by another bird and are constantly adding new songs and beats to their repertoire and annoying the casual by-passer. But what is astounding is that these birds have been found to have repertoires easily over 400 different songs, which grow as the birds age (Derrickson 1987). In fact, the size and quality of a male’s song repertoire is shown to have greater advantage in acquiring territory as they can deter other potential settlers with threatening bird calls (Howard 1974). Researchers agree that different songs and patterns are used for different purposes; burst singing was found to be most common in the fall when males and females were most territorial  (Logan, Budman et al. 1983). Most song patterns are used more for protecting territory, which is important for getting mates (Howard 1974).

Yet I was also curious about their lifestyle outside of just their singing. Digging through some archives, I came upon the finding that the northern mockingbirds are omnivorous feeders and often eat arthropods and insects close to the ground as well picking up fruits from trees (Breitwisch 1987). This completely explained why the pair that I saw was always hovering so close to the ground. Yet their unique behavior did not stop there, these birds also apparently do use flashing of wings to signal various messages (Sutton 1946) although their exact meanings aren’t always clear. Most of the time, flashing wing displays signaled warning against intruders and that you do not want to mess with these birds (Sutton 1946). Why you may ask? Because they WILL attack you! In fact, in a 1988 paper by Breitwisch, it was found that more aggressive birds were more successful in reproduction. The aggressive males showed greater ability to attract mates and protect their eggs because they were more prone to attack intruders (Breitwisch 1988). This pretty much means that we should probably stay away from these birds, and particularly not mess with their nests or their newly-fledged chicks.

After learning all this, my view of these birds has changed significantly. I always thought these birds were pretty song birds that didn’t really do much besides sing, but their mental and vocal capabilities are far beyond what I imagined and their aggressive behavior is definitely something to beware of. In short, if you didn’t take anything else out of this blog, just know that mockingbirds are basically the sirens of the avian family, they have a beautiful song but if you get too close, they might just claw you to death!

For additional information and pictures, I have placed some links and figures below.

Flickr (Open for commercial re-use): Northern mockingbird flashing wings

Flickr (Open for commercial re-use):  Northern mockingbird resting

Wikimedia Commons: Juvenile northern mockingbird

Fig. 2. The audiograph shows the sound patterns of the northern mockingbird. Each block represents one distinct pattern set of the mockingbird call. Image courtesy of Wildenthal 1965.

References:

Breitwisch, R., 1988. Sex differences in defense of eggs and nestlings by northern mockingbirds, Mimus polyglottos. Animal Behavior. 36(1): 62-72; http://www.sciencedirect.com/science/article/B6W9W-4KRFX07-8/2/7390675155798d9889b405f12c3692ff

Breitwisch, R., M. Diaz, R. Lee, 1987. Foraging Efficiencies and Techniques of Juvenile and Adult Northern Mockingbirds (Mimus polyglottos). Behavior. 101(1): 225-235;http://www.jstor.org/stable/4534598

Derrickson, K.C., 1987. Yearly and Situational Changes in the Estimate of Repertoire Size in Northern Mockingbirds (Mimus polyglottos). The Auk. 104(2): 198-207;http://www.jstor.org/stable/4087025

Logan, C.A., P.D. Budman, et al. (1983). “Role of chatburst versus song in the defense of fall territory in mockingbirds  (Mimus polyglottos).” Journal of Comparative Psychology 97(4): 292-301

Howard, R.D., 1974. The influence of sexual selection and interspecific competition on mockingbird song (Mimus polyglottos). Society for the Study of Evolution. 28(3): 428-438;http://www.jstor.org/stable/2407164

Sutton, G.M., 1946. Wing-flashing in the mockingbird. Wilson Ornithological Society. 58(4): 206-209;http://www.jstor.org/stable/4157522?seq=4

Wildenthal, J.L., 1965. Structure in Primary song of the Mockingbird (Mimus polyglottos). The Auk. 82(2): 161-189;http://www.jstor.org/stable/4082931?seq=5

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