Birding at MOSI Outside: Northern Mockingbird

In Harper Lee's classic novel, To Kill a Mockingbird, the character Miss Maudie explains to young Scout why mockingbirds should be protected. "Mockingbirds don’t do one thing but make music for us to enjoy," she says. "They don’t eat up people’s gardens, don’t nest in corncribs, they don’t do one thing but sing their hearts out for us. That’s why it’s a sin to kill a mockingbird."

Harper Lee portrayed many things very faithfully and honestly in her masterpiece, but I've always felt that she may not have quite had a real understanding of mockingbirds themselves. Northern Mockingbirds (Mimus polyglottus) are a common sight at MOSI Outside and throughout much of the country, where they are non-migratory year-round residents. They're often seen perched up high in trees or on rooftops, weaving dozens of different songs, calls, and sounds together as they keep watch for invaders to their territory.

And Northern Mockingbirds are definitely territorial. In the MOSI gardens, we've spent the winter watching various mockingbirds defending their winter feeding grounds from other birds, often diving and attacking to keep invaders from their chosen berry bushes. Northern Mockingbirds love berries, and so when Miss Maudie observed that "they don't eat up people's gardens", we can only assume she wasn't trying to grow cherries or blackberries. Northern Mockingbirds also happily eat insects and even visit feeders for seeds; their varied diet has helped them become one of the most successful and widespread songbirds in North America.

Another factor that may have helped their success is their general aggressiveness, especially during nesting season. Mockingbirds fiercely defend their nests from potential threats, and swoop down to attack with loud cries and even sharp pecks. They are known to attack stray cats, invader birds like hawks, and even humans, all with seemingly fearless bravado. They are also bold when feeding; one of our most memorable moments here at MOSI Outside came when we were out admiring the gorgeous color of a green katydid on the ground under an oak tree. While we stood there, a mockingbird flew in and grabbed the insect, its wings nearly brushing our faces in its eagerness to secure a good meal.

The "North" of their name distinguishes them from other species like the Bahama Mockingbird (Mimus gundlachii), seen only in extreme south Florida, and the Tropical Mockingbird (Mimus gilvus), found in Southern Mexico and Central America. Their scientific name, Mimus polyglottus, is very easy to understand - they mimic just about anything they hear, and more than once we've been fooled in the gardens into thinking a car alarm is going off... when it's actually just a mockingbird calling nearby.

Whatever else Miss Maudie may have thought about mockingbirds, she was right about one thing: it's a sin to kill them - literally. Northern Mockingbirds are protected by the Migratory Bird Treaty Act of 1918 (even though they don't migrate) and it's illegal to kill, capture, hunt, buy, or sell these birds. In the 19th century, mockingbirds were popular cage birds fetching outrageous prices, and the species was nearly erased from some parts of its region. Fortunately, the protection afforded it by the MBTA has led to its full recovery, and Northern Mockingbirds are common here at MOSI throughout the gardens and Historic Tree Grove all day long, every day of the year.